JPS6314068Y2 - - Google Patents

Description

[Detailed description of the invention] This invention prevents excessive overcompression of the compressor, and also prevents damage to the suction valve attached to the head of the cylinder due to an abnormal increase in cylinder internal pressure during liquid compression. The present invention relates to a compressor designed to do the following.

Generally, a compressor has a compressor part in a housing,
a cylinder that includes a built-in electric motor unit that operates a piston of a compressor unit, a cylinder that includes the piston is formed as a part of a frame that constitutes the compressor unit, and a suction valve and a discharge valve are provided in the head of the cylinder; It is configured to supply gas compressed to a predetermined pressure by sequentially suctioning, compressing, and discharging gas in conjunction with the reciprocating motion of the piston.

As shown in Figure 1, the suction valve and discharge valve are configured such that suction hole 3 and discharge hole 4 are not connected to each other on valve seat 2 attached to the end of cylinder 1, a ring-shaped suction valve 5 that opens and closes suction hole 3 is interposed between cylinder 1 and valve seat 2 so as to be able to be opened and closed freely, a discharge valve 6 that opens and closes discharge hole 4 is attached to the back surface of valve seat 2, and a discharge valve stopper 8 is attached to valve seat 2 via an elastic body 7 to constitute a valve mechanism.

This valve mechanism is designed to reduce the clearance volume [gap volume] formed between the top surface of the piston 9 and the discharge valve 6 when the piston 9 reciprocating in the cylinder 1 is at maximum compression [top dead center]. In order to improve the volumetric efficiency, the discharge hole 4 of the valve seat 2 is formed into a hollow circular shape, and a cylindrical protrusion 10 that can be inserted into the discharge hole 4 is formed on the pressing surface of the piston 9. The upper surface of the piston 9 is partitioned into an inner chamber A and an outer chamber B by the protrusion 10.

However, in this case, the protrusion 10 enters the discharge hole 4 of the valve seat 2 during the discharge stroke, and the pressing surface space of the piston 9 is separated into an inner chamber A and an outer chamber B by the protrusion 10. .

By the way, in order to make the clearance volume as small as possible when the piston 9 reaches the top dead center, there is a gap between the lower surface of the suction valve 5 and the upper edge surface of the piston 9, and between the discharge hole 4 and the protrusion 10. between, and valve seat 2
The gaps formed between the lower surface of the piston 9 and the upper center of the piston 9 are made as small as possible at the top dead center of the piston 9.

Therefore, in the state after the protrusion 10 starts to protrude into the discharge hole 4, the compressed gas passage area gradually becomes narrower, and the outer surface formed between the lower surface of the suction valve 5 and the upper edge surface of the piston 4 becomes narrower. Both the refrigerant gas in the side chamber B and the refrigerant gas in the inner chamber A formed between the lower surface of the valve seat 2 and the upper center of the piston 9 become difficult to flow as the piston 9 rises, and the flow resistance increases. However, this increases overcompression of the refrigerant gas. The degree of this overcompression is the inner chamber A and the outer chamber B.
, and the chamber with a larger volume change, the outer chamber B in the illustrated example, is more strongly overcompressed.

For this reason, there is a drawback that the inner chamber A or the outer chamber B tends to be in an excessively overcompressed state. Furthermore, this compressor generally has a suction hole 3 and a suction valve 5.
The liquid refrigerant in the suction gas tends to accumulate in a certain outer chamber B, resulting in a disadvantage that the suction valve 5 may be damaged during liquid compression.

In view of the above-mentioned conventional drawbacks, this invention prevents excessive overcompression of the compressor, prevents damage to the suction valve attached to the valve seat due to an abnormal increase in cylinder internal pressure during liquid compression, and at the same time of the machine
This invention provides a compressor that improves EER (energy efficiency ratio), and the configuration of this invention will be described below with reference to embodiments shown in the drawings.

Figure 2 is a drawing showing the overall configuration of a completely hermetic compressor, and in the figure, 20 is a bowl-shaped lower case 20a.
The upper case 20b has an inlet port (not shown), the lower case 20a has a discharge port (not shown), and the electric motor section A compression device consisting of a compressor section 21 and a compressor section 22 is built in, and this is elastically supported within the housing 20. 23 is a stator that constitutes the electric motor section 21; 24 is a rotor; 25
is a rotating main shaft, which integrally has a crankshaft 25a at its lower part and whose upper part is attached to the center of the rotor 24.

Reference numeral 26 denotes a frame that constitutes the compressor section 22 and supports the electric motor section 21, and has a bearing section 2 at the center of the upper surface side.
7, a support arm 28 is formed on the outer peripheral edge, and a cylinder 29 is integrally formed on a part of the lower surface side. Then, the stator 23 is placed on the upper surface of the support arm 28.
A cover 30 surrounding the electric motor section 21 is attached to the outer circumferential surface of the cover 30 using screws 31, etc., and the bearing section 27
A rotating main shaft 25 is rotatably supported therein via a metal 32. Also, the frame 26 is the housing 20
It is elastically supported via protrusions 34 and springs 35 by support metal fittings 33 fixed to an appropriate number of locations, for example, three locations, on the inner peripheral surface of the lower case 20a. A lower bearing 36 is attached to the lower surface of the frame 26 and supports the lower part of the rotating main shaft 25.

A piston 37 is slidably disposed within the cylinder 29. A cylindrical protrusion 38 that can be inserted into a discharge hole 44 of a valve seat 42 (to be described later) is provided on the pressing surface of the piston 37 to push the pressing surface of the piston 37 into the inner chamber C.
and an outer chamber D. As shown in FIGS. 3 and 4, a plurality (four) of small diameter communication holes 39 are bored in the bottom of the protrusion 38 to communicate the inner chamber C and the outer chamber D. There is.

Further, the piston pin 37a of the piston 37 and the crankshaft 25a of the rotating main shaft 25 are connected by a connecting rod 40.

Reference numeral 41 denotes a valve mechanism attached to the end of the cylinder 29, and as shown in FIG. An annular suction valve 45 that opens and closes the suction hole 43 is interposed between the cylinder 29 and the valve seat 42 so as to be openable and closable, and a discharge hole 4 is formed on the back of the valve seat 42.
4 is equipped with a discharge valve 46 that opens and closes the elastic body 47.
A discharge valve holder 48 is attached to the valve seat 42 via the valve mechanism. Further, the discharge hole 44 provided in the valve seat 42 of this valve mechanism 41 is formed in a hollow circular shape, and is formed in a trapezoidal shape into which the protrusion 38 provided on the pressing surface of the piston 38 described above can be inserted. 49 is a primary side discharge pipe provided to communicate with the discharge side of the valve mechanism 41; 50 is a primary side discharge pipe 49 and the lower case 20;
A secondary discharge pipe communicates with the discharge port a, and gas compressed and heated by these pipes is led out to the outside.

The action of the compressor made in this way is as follows:
When the rotation main shaft 25 is rotated, the crankshaft 25a integrated therewith rotates, and the piston 3
7 reciprocates within the cylinder 29, and when retracting, opens the suction valve 45 of the valve mechanism 41, closes the discharge valve 46, and directs the gas introduced into the housing 20 from the suction hole 43 of the valve seat 42 into the cylinder 29. When the gas is inhaled and moved forward, the suction valve 45 is closed to compress the gas, and when the gas reaches a predetermined pressure or higher, the discharge valve 46 is opened against the elastic body 47 to discharge the gas from the discharge hole 44 of the valve seat 42 to the primary discharge pipe 49. Furthermore, it is led out to the outside via the secondary discharge pipe 50, supplied to a predetermined device, and then introduced into the housing 20 again. Compressed gas is continuously supplied by repeating such operations.

In the discharge stroke during the above operation, the protrusion 38 provided on the pressing surface of the piston 37 enters the discharge hole 44 of the valve seat 42, and when the piston 37 reaches the top dead center, the pressing portion of the piston 37 The space is the protrusion 3
8 into an inner chamber C and an outer chamber D. Thereafter, as the piston 37 moves upward, the overcompression state increases in both the inner chamber C and the outer chamber D, but the chamber with the larger volume change is more strongly overcompressed.
For example, if the outer chamber D becomes excessively overcompressed than the inner chamber C, the communication hole 3 formed at the bottom of the protrusion 38
9, the gas in the outer chamber D that has become overcompressed escapes to the inner chamber C, which prevents unnecessary back pressure from being applied to the piston 37 and improves the EER of the compressor. can. Also, when compressing the liquid, the gas containing the liquid escapes from the outer chamber D to the inner chamber C through the communication hole 39.
You can prevent troubles that may occur if 5 is damaged.

As explained above, this invention forms the hollow circular discharge hole 44 in the valve seat 42, while the piston 3
A cylindrical protrusion 38 that can be inserted into the hollow circular discharge hole 44 is provided on the pressing surface of 7, and the protrusion 38 protrudes into the discharge hole 44 and causes the piston 37 to be pressed. When the surface portion is partitioned into an inner chamber C and an outer chamber D, the protrusion 38 is provided with a communication hole 39 through which the inner chamber C and the outer chamber D communicate with each other. When the piston 37 rises and the pressing surface of the piston 37 is separated into two internal and external chambers, an inner chamber C and an outer chamber D, by the protrusion 38 provided on the pressing surface of the piston 37, these two chambers are communicated with each other. Since they are in communication through the hole 39, it is possible to prevent excessively overcompressed refrigerant gas from overflowing through the communicating element 39 and becoming in an excessively overcompressed state. Also, during liquid compression, the liquid refrigerant in the outer chamber D is guided to the inner chamber C through the communication hole 39, which prevents the suction valve from cracking during liquid compression and improves the performance of the compressor. can.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of main parts showing the piston and valve mechanism of a conventional compressor, Fig. 2 is a sectional view showing the overall mechanism of the compressor according to this invention, and Fig. 3 is a piston of the compressor according to this invention. FIG. 4 is a sectional view of essential parts showing the valve mechanism, and FIG. 4 is a perspective view of the piston. 29...Cylinder, 37...Piston, 38...
...Protrusion, 39...Communication hole, 42...Valve seat, 43...
...Suction hole, 44...Discharge hole.

Claims (1)

[Scope of utility model registration request] A hollow circular discharge hole 44 is formed in the valve seat 42 attached to the head of the cylinder 29 of the compressor, while the hollow circular discharge hole 44 is formed in the pressing surface of the piston 37 reciprocating within the cylinder 29. A cylindrical protrusion 38 that can be inserted into the piston 37 is provided, and the protrusion 38 projects into the discharge hole 44 and partitions the pressing surface of the piston 37 into an inner chamber C and an outer chamber D. A compressor characterized in that the protrusion 38 is provided with a communication hole 39 through which the inner chamber C and the outer chamber D communicate with each other when the compressor is closed.