WO2004099617A1

WO2004099617A1 - Refrigerant compressor

Info

Publication number: WO2004099617A1
Application number: PCT/JP2004/006578
Authority: WO
Inventors: Masanori Kobayashi
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2003-05-12
Filing date: 2004-05-10
Publication date: 2004-11-18
Also published as: EP1541868A1; KR20050033613A; EP1541868A4; US20060039808A1; JP2004360686A

Abstract

A valve plate has suction holes and suction reed valves opening and closing the suction holes. At least two of the suction reed valves have different natural frequencies. In this structure, one reed valve has a high natural frequency. Consequently, even when operation frequency increases to a higher level, a compressor can efficiently suck a refrigerant into a cylinder without having a delayed closure and reduced lift amount, and this results in higher refrigeration capability and compression efficiency of the compressor.

Description

Specification

Refrigerant compressor technical field

The present invention relates to an improvement in the efficiency of a hermetic compressor used for a freezing and refrigeration apparatus. Background art

In recent years, the efficiency of hermetic compressors used in freezers and the like has been strongly desired. Conventional hermetic compressors improve the compression efficiency by, for example, increasing the suction efficiency by using two suction holes in the valve unit in the compression section. Such a compressor is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-175174. Hereinafter, an example of a conventional hermetic compressor will be described with reference to the drawings.

FIG. 6 is a sectional view of a conventional refrigerant compressor, and FIG. 7 is an exploded perspective view of a valve of the conventional refrigerant compressor. An outlet 52A, which is one end of a suction pipe 52, is connected to the closed vessel 51, and the other end of the suction pipe 52 is connected to a low-pressure side pipe (not shown) of the refrigeration cycle. The motor 53 is composed of a stator 54 and a rotor 55, and drives the compression unit 56. Refrigeration oil 57 is stored at the bottom of the sealed container 51. The coil spring 58 elastically supports the module 53 and the compression section 56.

The compression section 56 includes a cylinder head 61, a cylinder block 62, a valve plate 64, a suction reed valve 67, a piston 68, a connecting rod 70, and a suction muffler 3. 0. The cylinder head 61 forms a suction space 61A and a discharge space 61B. The cylinder block 62 has a cylinder 63. The valve plate 64 has two suction holes 65 and two discharge holes 66. The suction reed valve (hereinafter, valve) 67 has a deformed portion 67A. The connecting rod 70 is connected to the eccentric part 69 A of the crank shaft 69. The suction muffler 30 is connected to the suction space 61A via the communication pipe 30A and the suction hole of the valve plate 64. Communicates with 65 and draws refrigerant gas from the inlet 30B.

The operation of the refrigerant compressor configured as described above will be described below. First, the compression section 56 is driven by the motor 53, and the piston 68 reciprocates in the cylinder 63. The low-temperature and low-pressure refrigerant gas returned from the external refrigeration cycle (not shown) is first drawn into the closed vessel 51 from the suction pipe 52. The refrigerant gas is further sucked from the inlet 30B of the suction muffler 30 and passes through the suction hole 65 through the communication pipe 3OA. By deforming the deformed portion 67 A of the valve 67 during the suction stroke, the coolant gas is guided to the cylinder 63 by opening the valve 67. During the compression stroke, the valve 67 is closed, and the refrigerant gas is compressed to a high temperature and high pressure, passes through the discharge port 66, passes through a discharge pipe (not shown), and is guided to an external refrigeration cycle (not shown) for refrigeration. Make

At this time, the valve 67 is designed to have a natural frequency that opens and closes in a timely manner in accordance with the low-speed operation frequency, so the compressor has low suction loss and can operate with high volumetric efficiency. .

However, if the operating frequency changes from a low operating frequency to a high one due to a change in cooling load conditions, the timing of the opening / closing operation determined by the natural frequency of the valve 67 will be shifted. At this time, even if the pressure in the cylinder 63 exceeds the pressure in the suction space 61A of the cylinder head 61, the valve 67 does not complete the closing operation. As a result, the refrigerant gas flows backward due to the delay in closing and the volume efficiency is reduced, and the refrigeration capacity and refrigeration efficiency are reduced. In order to reduce the backflow of the refrigerant gas due to the delay of closing the valve 67, measures to design a high natural frequency corresponding to high-speed operation can be considered.In this case, the spring constant of the deformed part 67A increases, The amount of deflection of the deformed part 67 A decreases, the suction loss increases, and the refrigeration capacity and refrigeration efficiency decrease. Disclosure of the invention

A refrigerant compressor according to the present invention includes a piston, a cylinder, and a valve plate. The valve plate is provided at the open end of the cylinder. It has a number of suction holes. The refrigerant compressor according to the present invention further has a plurality of suction lead valves provided between the open end of the cylinder and the valve plate to open and close the plurality of suction holes, respectively. At least one of the suction reed valves has a different natural frequency than the other reed valves. With this configuration, even if the operating frequency changes, a delay in closing the suction reed valve and a decrease in the amount of deflection are prevented. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional view of a refrigerant compressor according to an embodiment of the present invention. FIG. 2 is a front view of a suction reed valve in the refrigerant compressor of FIG.

FIG. 3 is a cross-sectional view of a cylinder head of the refrigerant compressor of FIG. 1. FIG. 4 is a cylinder pressure and a reed valve deflection during one stroke in a low-speed operation of the refrigerant compressor according to the embodiment of the present invention. FIG.

FIG. 5 is a diagram showing the pressure in the cylinder and the amount of deflection of the reed valve during one stroke in the high-speed operation of the refrigerant compressor in the embodiment of the present invention. FIG. 6 is a sectional view of a conventional refrigerant compressor.

FIG. 7 is an exploded perspective view of a valve of the refrigerant compressor of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a cross-sectional view of a refrigerant compressor according to an embodiment of the present invention. FIG. 2 is a front view of the suction reed valve. Fig. 3 is a sectional view of the cylinder head.

An outlet 2A, which is one end of a suction pipe 2, is connected to the closed vessel 1, and the other end of the suction pipe 2 is connected to a low-pressure side pipe (not shown) of the refrigeration cycle. The motor 3 includes a stator 4 and a rotor 5 and drives a compression unit 6. The refrigerating machine oil 7 is stored at the bottom of the closed container 1. The coil spring 8 elastically supports the motor 3 and the compression section 6.

The compression unit 6 includes a cylinder head 101, a cylinder block 12 and It is composed of a valve plate 110, a suction reed valve (hereinafter, a valve) 120A, 120B, a piston 18, a connecting rod 20, and a suction muffler 130. The cylinder head 101 forms a suction space 101A and a discharge space 101B. The cylinder block 12 has a cylinder 13. The connecting rod 20 is connected to the eccentric part 19 A of the crankshaft 19. The suction muffler 130 communicates with the suction space 110 A through the pipe 13 OA, and communicates with the suction holes 1 12 A and 1 12 B of the valve plate 110, and the inlet section 130 B More refrigerant gas is sucked.

The valve plate 110 has suction holes 112A and 112B and a discharge hole (not shown). Suction holes 1 1 2 A, 1 1 2 B are openings 1 1 4 from cylinder 13 opening 1 1 4 A, 1 1 4 B to cylinder head 1 0 1 side of valve plate 1 1 10 Inclines to C, 114D in the direction in which the distance between them decreases. Valves 120A and 120B have deformed portions 122A and 122B having different lengths, respectively. Since the deformed part 122 A is longer than the deformed part 122 B, the spring constant of the valve 120 A is smaller, and the valve 120 A has a lower natural frequency than the valve 120 B. I have. The shapes of the valves 122A and 120B are asymmetric with respect to the center lines 124A and 124B of the deformed parts 122A and 122B. The positions of the center points of the suction holes 1 12 A and 1 12 B correspond to the points 1 26 and 1 26 B of the valves 1 20 A and 1 208 respectively.

The seal portions 128 A and 128 B seal the suction holes 112 A and 112 B provided in the valve plate 110.

The operation of the refrigerant compressor of the present embodiment configured as described above will be described below. FIG. 4 is a cylinder pressure and reed valve deflection diagram during one stroke in a low-speed operation of the refrigerant compressor according to the present embodiment. FIG. 5 is a diagram showing the pressure in the cylinder and the amount of deflection of the reed valve during one stroke in the high-speed operation of the refrigerant compressor.

The compression section 6 is driven by the motor 3, and the piston 18 reciprocates in the cylinder 13. The low-temperature and low-pressure refrigerant gas returned from the external refrigeration cycle (not shown) is first drawn into the closed vessel 1 from the suction pipe 2. It is. Refrigerant gas is further sucked in from the inlet portion 130B of the suction muffler 130, and passes through the suction holes 1 12A and 112B via the communication pipe 13OA. By deforming the deformed portions 122A and 122B of the valves 122A and 122B during the suction stroke, the refrigerant gas opens the valves 122A and 122B and the cylinder 1 Guided to 3. During the compression stroke, the valves 120A and 120B are closed, and the refrigerant gas is compressed to a high temperature and pressure, passes through a discharge pipe (not shown) from the discharge port, and is led to an external refrigeration cycle to perform refrigeration. Eggplant

When the piston 18 reciprocates in the cylinder 13, the piston 18 moves to the bottom dead center in the suction stroke. Under low-speed operation, during this suction stroke, the gas pressure load generated by the differential pressure when the pressure 140 in the cylinder 13 falls below the pressure in the suction space 101A of the cylinder head 101 is reduced. Acts on valves 120A and 120B. At this time, at point 140 A, the suction reed valves 12 OA and 120 B begin to open, and refrigerant gas is sucked into the cylinder 13. At point 140 A, the gas pressure load generated by the differential pressure is due to the bending load of the valves 120 A and 120 B and the viscosity of the refrigerating machine oil at the seals of the valves 120 A and 120 B. It means the point at which it becomes larger than the resultant force with adhesion.

In the compression stroke, the valves 120 A and 120 B are connected to the point at which the pressure in the cylinder 13 exceeds the pressure in the suction space 101 A of the cylinder head 101. Close with B, and the suction of refrigerant gas from suction muffler 130 is completed.

Between point 140 A and point 140 B, valve 120 A performs two opening and closing operations at the natural frequency of the primary deformation mode while bending the deformation section 122 A. Repeat OA. Since the natural frequency corresponding to the low-speed operation frequency has been selected for the valve 12OA, the valve 120A closes at almost the same timing as the point 140B. In addition, because the spring constant of the valve 120 A is small, even under the condition where the flow rate of the intake gas is low at the time of low-speed operation, the suction loss does not increase due to the insufficient amount of deflection.

Also, if the valve 120 B, the natural frequency higher than the valve 120 A, It has a spring constant and repeats four opening / closing operations 150 B between point 140 A and point 140 B. At this time, the valve 120B opens a large amount with a predetermined amount of flexure corresponding to the refrigerant circulation amount in the first to third opening / closing operations 150B. In the fourth opening / closing operation, the pressure difference between the inside of the cylinder 13 and the suction space 101A of the cylinder head 101 is very small because it is in the compression stroke. At this time, the refrigerant gas flows through the inlet hole 112A of the valve 120A, which is more greatly bent. Therefore, the amount of the refrigerant gas flowing through the suction hole 112B of the valve 120B becomes small, and the dynamic pressure due to the flow of the refrigerant gas decreases. That is, the valve 120B completes the opening / closing operation near the point 141B with almost no bending.

Therefore, the backflow of the refrigerant gas due to the closing delay of the valves 120A and 120B is prevented, and the increase in suction loss due to an excessively small deflection amount during the suction stroke is also prevented. For this reason, the volume efficiency is increased.

Also, in the case of high-speed operation, the knob 124B repeats three opening / closing operations 151B between the point 141A and the point 141B, and performs the predetermined operation according to the refrigerant circulation amount. Point 14 1 A is the point when the pressure in cylinder 13 drops below the pressure in cylinder head 101 suction space 101 A Means Also, the point 141B indicates the point in time when the pressure in the cylinder 13 exceeds the pressure in the suction space 101A of the cylinder head 101.

The valve 120 A opens a large amount with a predetermined amount of deflection corresponding to the amount of circulating refrigerant at the first opening and closing operation 15 1 A. On the other hand, in the second opening / closing operation, the differential pressure between the inside of the cylinder 13 and the suction space 101A of the cylinder head 101 is very small because it is in the compression stroke. Therefore, after the second time, the refrigerant gas passes through the inlet hole 112B of the valve 120B, which is greatly bent. Therefore, the valve 120A completes the opening / closing operation near the point 141B with almost no bending.

Therefore, even in the case of high-speed operation, the refrigerant gas is efficiently circulated without delay in closing the valves 12 OA and 120 B and insufficient deflection. Sucked into Linda 13 Therefore, even when the operating frequency changes, the refrigerating capacity and compression efficiency of the compressor increase.

Also, the shapes of the knobs 120A and 120B are asymmetric with respect to the center lines 124A and 124B of the deformed portions 122A and 122B. For this reason, the points of action 12 6 A, 12 B of the gas pressure load acting on the valves 12 A, 12 B and the center line of the radial deformation of the valves 12 OA, 12 OB 1 2 4 A and 1 24 B shift. As a result, the valves 120A and 120B start opening while being torsionally deformed. That is, the torsional moment caused by the gas pressure load acts on the valves 12OA and 120B. For this reason, the force of peeling off the adhered part due to the viscosity of the refrigerating machine oil 7 acts on one side of the circular seal parts 128 A, 128 B of the valves 120 A, 120 B, and the valve 1 20 A and 120 B are easy to open. Therefore, the opening of the valves 120A and 120B in the suction stroke starts earlier. Therefore, the refrigerant gas is efficiently sucked into the cylinder 13 and the refrigeration capacity and the compression efficiency are increased. In FIG. 2, the shapes of the valves 120 A and 120 B are asymmetric with respect to the center lines 124 A and 124 B of the deformed parts 122 A and 122 B, respectively. However, only one may do so.

The refrigerant gas in the sealed container 1 passes through the suction space 101 in the high-temperature cylinder head 101 via the suction muffler 130, and the suction hole 1 provided in the valve plate 110. Inhaled into cylinder 13 from 12 A and 11 B. Here, the refrigerant gas in the cylinder 13 is brought into a high temperature state of about 100 by compression action and is discharged to the discharge space 101 B of the cylinder head 101. As a result, the cylinder head 101 is heated to a high temperature state of about 80 ° C.

At this time, the interval between the two suction holes 1 1 2 A and 1 1 2 B of the suction space 1 0 1 A in the cylinder head 101 is at least as small as the seal 1 2 28 A and the seal 1 2 8 B Is necessary to add the width of Here, if the suction holes 112A and 112B are inclined as shown in Fig. 3, there is no need to consider the width between the seal part 128A and the seal part 128B, and the suction hole 1 The interval between 12 A and 11 B can be greatly reduced. Thus, the volume of the suction space 101A and the heat receiving area in the cylinder head 101 can be made small, and the heat transfer to the flowing refrigerant gas is reduced. Therefore, the temperature of the cold soot is kept low, the density of the gas refrigerant is high, the refrigerant circulation amount is large, and the refrigeration capacity and compression efficiency are high. In FIG. 3, both the suction holes 112A and 112B are inclined, but may be provided only to one of them.

In the present embodiment, the number of valves 120A and 120B is two, but the same effect can be obtained with three or more valves.

In the present embodiment, the natural frequency is changed by changing the length of the valves 120A and 120B, but the width and shape of the valves 120A and 120B are changed. The same effect can be obtained even if the natural frequency is changed by changing the natural frequency.Also, in the present embodiment, the number of times of opening and closing in one stroke of the valves 120A and 120B is described as 2 to 4 times. However, the same effect can be obtained if it is performed once or more. Industrial applicability

A refrigerant compressor according to the present invention includes a piston, a cylinder, and a valve plate. The valve plate is provided at an open end of the cylinder and has a plurality of suction holes. The refrigerant compressor according to the present invention further includes a plurality of suction reed valves provided between the open end of the cylinder and the valve plate, and respectively opening and closing the plurality of suction holes. At least one of the suction lead valves has a different natural frequency than the other reed valves. With this configuration, the refrigeration capacity and compression efficiency of the refrigerant compressor can be increased, so that it can be applied to applications such as air conditioners and refrigeration units.

Claims

The scope of the claims

1. Piston and

A cylinder for storing the piston,

A valve plate provided at an open end of the cylinder and having a first suction hole and a second suction hole;

A first suction reed valve provided between the open end of the cylinder and the valve plate to open and close the first suction hole;

A second suction reed valve that is provided between the open end of the cylinder and the pulp plate, opens and closes the second suction hole, and has a different natural frequency from the first reed valve.

Refrigerant compressor.

2. The first suction reed valve has a first deformed portion, the second suction reed valve has a second deformed portion, and the shape of the first suction reed valve is a center line of the first deformed portion. Or the shape of the second suction lead valve is asymmetric with respect to the center line of the second deformable portion.

The refrigerant compressor according to claim 1.

3. At least one of the first suction hole and the second suction hole extends from the opening end surface of the cylinder of the valve plate to the other end surface, and a distance between the first suction hole and the second suction hole. Is inclined in the direction in which

The refrigerant compressor according to claim 1.