JP2858302B2 - Gas compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas compressor used as a refrigerant compressor or the like of a vehicle air conditioner, and more particularly to a gas compressor which reduces a discharge pulsation of a gas compressor to reduce noise.

[0002]

2. Description of the Related Art Conventionally, a gas compressor sucks refrigerant gas,
Since the refrigerant gas is pressurized and delivered in each step of compression and discharge, a specific pressure fluctuation (hereinafter referred to as pulsation) occurs in the discharge chamber and is transmitted from the discharge port to the outside of the compressor. This also caused noise corresponding to the pulsation. The situation during this time will be described by taking a conventional gas compressor as an example. FIG. 5 is a longitudinal sectional view of a conventional gas compressor, and FIG. 6 is a sectional view taken along line AA. The gas compressor mainly includes a housing 1 having a substantially elliptical inner peripheral surface, and a cylinder 4 closed by a front housing side plate 2 and a rear housing side plate 3 for fixing the front and rear end surfaces of the housing 1, respectively. . A rotor 6 rotatably supported by a shaft 5 in a cylinder 4
And a vane 7 which is fitted to the rotor 6 so as to be able to come and go in the radial direction. Between the cylinder 4 and the rotor 6 whose front and rear end faces are closed, two compression chambers 8 are defined at substantially symmetric positions.

The housing 1 fixed to the front housing side plate 2 and the rear housing side plate 3 is fitted in a rear housing 9. A front housing 10 is fixed to an outer end surface of the front housing side plate 2. An oil separator 11 for separating oil from refrigerant gas is fixed to an outer end surface of the rear housing side plate 3. A refrigerant gas discharge port 12 is formed on the upper surface of the rear housing 9, and a refrigerant gas suction port 13 is formed on the upper surface of the front housing 10. The discharge port 12 communicates with a discharge chamber 14 defined by the rear housing side plate 3 and the rear housing 9, and the suction port 13 communicates with a suction chamber 15 defined by the front housing side plate 2 and the front housing 10. ing. The housing 1 has a cylinder discharge port 16 for discharging the compressed refrigerant gas, and a reed valve 17 having one end fastened to the discharge surface of the cylinder discharge port 16 so as to be openable and closable. Are provided at substantially symmetrical positions.

In such a configuration, the refrigerant gas compressed in each compression chamber 8 flows from the cylinder discharge port 16 to the reed valve 1.
7, and passes through a first discharge port 18 (not shown) penetrating the rear housing side plate 3. Thereafter, the refrigerant gas is discharged into the discharge chamber 14 from a wire mesh oil separator 19 fitted to the oil separator 11. At that time, the refrigerant gas separated from the oil contained in the refrigerant gas and from which the oil is removed is led from the discharge port 12 to a hose (not shown) and sent to a condenser or the like. Five vanes 7 are inserted into the rotor 6 shown in FIG. 6 and are involved in each process of suction, compression and discharge of the refrigerant gas. Since the cylinder discharge port 16 is provided at a position substantially opposite to the housing 1, the rotation of the rotor 6 causes five gas pressure fluctuations per one rotation of the rotor 6 from one cylinder discharge port 16. Further, from the other cylinder discharge port 16 facing the opposite side, a gas pressure fluctuation having a phase difference of 180 degrees occurs because an odd number of vanes are used. Therefore,
From the discharge port 12, a combined gas pressure fluctuation, that is, a pulsation corresponding to ten times per rotation of the rotor 6 is generated.

The number of pulsations per second is wide because the shaft 5 of the gas compressor is rotationally driven in conjunction with an engine mounted on the vehicle. For example, the rotation of the engine has a fluctuation range of about 1000 RPM when idling and about 7000 to 8000 RPM in the red zone. That is, a pulsation occurs in accordance with the rotation speed, and at the same time, it causes noise with large frequency fluctuation. Conventionally, in order to reduce such pulsation, a muffler is connected to a discharge port 12 of a gas compressor.
Was known to be attached to the end of the
No. 6005).

[0006]

However, in the above-described conventional silencing technology, the size of the gas compressor is increased and the manufacturing cost is increased by the amount corresponding to the muffler. Further, the discharge chamber 14
There is a possibility that noise leaking to the outside through the rear housing 9 cannot be eliminated. SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and with the recent quietness of the vehicle side, the pulsation leaking to the outside is small, the quietness is high, and the gas compression is small, lightweight and inexpensive to manufacture. The purpose is to provide a machine.

[0007]

According to the present invention, both end surfaces of a housing are closed by a front housing side plate and a rear housing side plate having one or a plurality of first discharge ports for allowing refrigerant gas to pass therethrough. Cylinder, a rotor supported by a shaft in the cylinder and rotating, one or more compression chambers defined by an outer peripheral surface of the rotor and an inner peripheral surface of the cylinder, and pressurization in the compression chamber. Refrigerant
One or more of the cylinders for discharging gas
One cylinder discharge port and one discharge surface of the cylinder discharge port
A reed valve which is fastened to openably other end edge is secured to the outer end face of the rear housing plate, said cylinder
An oil separator having one or a plurality of second discharge ports for discharging the refrigerant gas discharged from the discharge port and separating oil in the refrigerant gas, the rear housing side plate, and a peripheral end surface of the rear housing side plate A gas compressor having a discharge chamber defined by a rear housing fixed to an outer end surface of the rear housing side plate or an inner end surface of the oil separator. The reed valve is fully opened from one discharge port to one or more second discharge ports of the oil separator.
A muffling passage having a passage area of an open area when the muffler was placed was provided.

[0008]

[0009]

[0010]

[0011]

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 showing the first embodiment of the present invention, the compression mechanism comprises front and rear end faces of a housing 1 on a front housing side plate 2 and a rear housing side plate 3.
And corresponds to the cylinder 4 in which the rotor 6 fitted with the vane 7 is installed (hereinafter, the same). An oil separator 11 for separating oil is fixed to the outer end surface of the rear housing side plate 3. Instead of the wire mesh oil separator 19 fitted to the oil separator 11, the discharge port 20 of the oil separator 11 has a pipe cross-sectional area small enough not to abnormally increase the pressure in the compression chamber 8, For example, one end of a copper tube 25 having a long path length is connected. The other end of the copper tube 25 is configured to open into the discharge chamber 14. Next, the operation will be described. When sound propagates through a thin tube, the attenuation of the sound varies depending on the material of the tube wall, but even with a smooth metal tube, the amount of attenuation is greater than that in air. Ki
According to Rchhof, the damping constant α is

(Equation 1) However, C: velocity of sound [m] R: radius of the tube For a square tube, the above equation is

(Equation 2) Here, C: sound velocity [m] D: inner diameter That is, sound attenuation by a pipe is inversely proportional to the radius and inner diameter of the pipe and proportional to the length of the pipe. In many experimental results, the attenuation was 10 to 15 due to other factors than the value calculated in Equation 1.
Percent larger.

In this embodiment, the copper tube 25 is used for the reasons described above.
Was experimentally adopted, the cross-sectional area of the pipeline was reduced to such an extent that the pressure in the compression chamber 8 was not abnormally increased, and the length of the pipeline was secured as long as possible. Here, the inventor considered the open area when the reed valve 17 is opened to the maximum as one assumption of the pipe cross-sectional area that does not abnormally increase the pressure in the compression chamber 8 (hereinafter the same). As a result, the pulsation at the discharge port 12 became extremely small. It was also confirmed that the longer the pipe length, the greater the noise attenuation. Next, FIG. 2 shows a second embodiment of the present invention. In FIG.
(A) is a simplified configuration diagram of the gas compressor, and (B) is an external view of the rear housing side plate 3.

The rear housing side plate 3 is provided with a first discharge port 18.
Muffling passage 2 whose passage cross-sectional area is small and the passage distance is as long as possible so that the internal pressure of the compression chamber 8 does not rise extremely to the second discharge port 20 of the oil separator 11.
1 is arranged. And the noise reduction passage 21
The upper surface is sealed and fixed by an oil separator 11 .
And discharges refrigerant gas to the oil separator 11.
The second discharge port 20 is opened. That is, the discharge port 2
Refrigerant gas discharged from 0 is oil separated by an oil separator such as a wire mesh
It is supposed to be. Also, the oil separator 11
The cross-sectional area S1 of the second discharge port 20 is so small that the pressure in the compression chamber 8 does not abnormally increase. Next, the operation will be described. As described in Equation 1 or Equation 2, it is necessary to secure a small passage cross-sectional area and a long passage distance in order to attenuate noise. However, since various existing bolt holes are present in the rear housing side plate 3, the noise reduction passage 21 is arranged so as to meander so as to avoid the bolt holes (not shown) as shown in FIG. Established. In the present embodiment, the passage distance of the noise reduction passage 21 was about 15 cm. As a result, the noise was reduced to a considerable extent.

Although a cover for closing may be specially provided on the upper surface of the muffling passage 21, the number of parts can be reduced by also using the oil separator 11. Further, although the silencing passage 21 is provided on the outer end surface of the rear housing side plate 3, the same applies when the muffler passage 21 is provided on the inner end surface of the oil separator 11. According to the present embodiment, the number of parts is reduced by not using the copper tube 25 as compared with the first embodiment, the assembling process is the same as the conventional one, the manufacturing cost is hardly increased, and the reliability and durability are the same as the conventional one. There are advantages. On the other hand, when sound propagates through the tube, if there is a change in cross section or impedance change such as a pore that leads to the outside, some of the sound will be reflected and the propagation of a specific frequency will decrease as a result. I can do it. The amount of noise attenuation in this case is related to the change ratio of the cross-sectional area of the tube. According to the calculation based on the acoustic impedance, the attenuation is approximately 0.5 dB when the cross-sectional area change ratio S2 / S1 of the tube is twice, approximately 2 dB when the ratio is three times, and approximately 5 dB when the ratio is ten times. . Therefore, the cross-sectional area S1 of the second discharge port 20 of the oil separator 11 is reduced so as not to abnormally increase the pressure in the compression chamber 8 and discharged to the discharge chambers 14 having different cross-sectional areas S2. A sound attenuation effect by S2 / S1 can be obtained. On the other hand, the cross-sectional area of the discharge port 12 is the same size as the conventional one, but is still sufficiently smaller than the cross-sectional area S2. In this case, the change S2 / S1 in the cross-sectional area can secure a large ratio by the large volume of the discharge chamber 14, so that the sound attenuation effect is also large.

As described above, since the silencing passage 21 is provided in the rear housing side plate 3 and the cross-sectional area S1 of the second discharge port 20 of the oil separator 11 is reduced, there is no major design change in the gas compressor. At the outlet of the discharge port 12, a damping effect of about 1/10 in the pressure value could be obtained. This corresponds to a 20 dB attenuation. Next, FIG. 3 shows a third embodiment of the present invention. In FIG. 3, the rear housing side plate 3 and the oil separator 11 have the same configuration as that of the above-described second embodiment.
An auxiliary side plate 22 further provided with a muffling passage 21 is interposed between the oil separator 11 and the oil separator 11. Next, the operation will be described. Compared with the second embodiment, the passage distance can be increased by the extension of the muffling passage 21 by the auxiliary side plate 22, and the noise can be further reduced. By stacking the auxiliary side plates 22 in a plurality of stages, the passage distance of the muffling passage 21 can be further increased. However, since there are disadvantages such as an increase in the number of parts of the auxiliary side plate 22 and a decrease in the volume of the discharge chamber 14, consideration must be given to a balanced form.

Next, FIG. 4 shows a fourth embodiment of the present invention. In the above-described second embodiment, the case where one compression chamber 8 is provided and the rear housing side plate 3 is provided with one first discharge port 18 is illustrated, but FIG. 4 illustrates two compression chambers 8A and 8B. And the rear housing side plate 3 has two first discharge ports 18A and 18B corresponding to the respective compression chambers. In FIG. 4A, the refrigerant gas discharged from the two first discharge ports 18A and 18B is discharged to the two second discharge ports 20A and 20B via the two silence passages 21A and 21B, respectively. Show the case. In this case, the pulsating components generated in the two compression chambers 8 </ b> A and 8 </ b> B, each having a half-wave phase difference, merge in the discharge chamber 14. The noise reduction passages 21A and 21B are
As in the second embodiment, it is preferable that the cross-sectional area of the passage is as small as possible so that the internal pressure in A and 8B is not extremely increased, and the length of the conduit is as long as possible. The point of ensuring a small area and a long pipe length is as follows.

FIG. 4B shows two first discharge ports 18A,
The refrigerant gas discharged from the cooling passages 18B is
A case is shown in which, after once merging in the plane of the rear housing side plate 3 via A and 21B, it is further discharged to one discharge port 20 via a sound deadening passage 21C. In this case, the pulsating components having a half-wave phase difference generated in the two compression chambers 8A and 8B merge in the plane of the rear housing side plate 3, and the pulsating peaks and valleys interfere with each other. Will be. That is, a cancellation effect due to the phase difference can be expected. At this time, it has been confirmed from the experimental results of the inventor that the effect of canceling out the phase difference is greater when the pipe lengths of the noise reduction passages 21A and 21B are equal to each other until the merge. Hereafter, the point of making the distance equal is the same). FIG. 4C shows the second first discharge port 1.
This shows a case where the refrigerant gas discharged from 8A and 18B joins immediately before being discharged to one discharge port 20 via the silence passages 21A and 21B, respectively. In this case, the second compression chamber 8
The pulsating components having a half-wave phase difference generated in A and 8B merge immediately before being discharged to the discharge port 20 of the rear housing side plate 3, and the phases cancel each other.

FIG. 4D shows two first discharge ports 18A,
A case is shown in which the refrigerant gas discharged from 18B joins immediately before being discharged to one discharge port 20 via the silence passages 21a and 21b each formed by a plurality of lines. That is, FIG.
The noise reduction passages 21A and 21B of FIG.
This corresponds to the case of dividing into 1a and 21b. Such division of the muffling passage can be applied to FIG. By dividing the muffling passage, the passage cross-sectional area of each passage can be further reduced, and the effect of damping by Equation (1) or Equation (2) can be further expected. In addition, it is possible to sufficiently secure the total cross-sectional area of the divided muffling passages, and it is not necessary to consider a rise in the internal pressure of the compression chamber 8. The divided muffling passages may be arranged in parallel with each other as in this embodiment, or may be arranged separately from each other.

FIG. 4E shows the noise reduction passages 21A and 21B.
Shows a case in which a plurality of cavities are arranged in the middle of the process. As described above, when a sound propagates through a tube, if there is a change in cross section or the like, propagation of a specific frequency can be reduced. Therefore, by arranging a plurality of cavities 30 having a cross-sectional area S4 different from the passage cross-sectional area S3 of the muffling passage in the middle of the muffling passages 21A and 21B, it is possible to reduce the passage cross-sectional area and secure a long pipe length. In addition to the effects of the above-described embodiments, a sound attenuation effect due to the change S4 / S3 in the cross-sectional area can be obtained. In this case, in order to ensure a large cross-sectional area S4 of the cavity 30, the cavity 30 is formed using both the rear housing side plate 3 and the oil separator 11.
May be formed.

FIG. 4F shows a plurality of cavities 30 having a cross-sectional area S4 different from the passage cross-sectional area S3 of the muffling passage in the middle of the plurality of muffling passages 21a and 21b shown in FIG. This shows a case in which the components are arranged in series. In this case, in addition to the effect of dividing the muffling passage and reducing the passage cross-sectional area of each muffling passage, a sound damping effect due to the change in cross section S4 / S3 can be obtained. The cavity 30 may be formed by continuously changing the cross section of the passage in the pipe length direction (not shown). Although the rear housing side plate 3 and the oil separator 11 used in this embodiment are made of aluminum, the sound attenuation effect may be devised by changing the material to another material. Further, the number of the compression chamber, the first discharge port, and the second discharge port is not limited to one or two.

[0022]

As described above, according to the present invention, the passage cross-sectional area of the muffling passage is defined as the open area when the reed valve is fully opened, which hinders the normal operation of the gas compressor. As a result, noise generated due to pulsation can be suppressed to the maximum.

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[Brief description of the drawings]

FIG. 1 is a simplified configuration diagram of a gas compressor showing a first embodiment of the present invention.

FIG. 2 is a simplified configuration diagram of a gas compressor showing a second embodiment of the present invention.

FIG. 3 is a simplified configuration diagram of a gas compressor showing a third embodiment of the present invention.

FIG. 4 is a simplified configuration diagram of a gas compressor showing a fourth embodiment (various modes of a noise reduction passage) of the present invention.

FIG. 5 is a longitudinal sectional view of a conventional gas compressor.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 housing 2 front side housing side plate 3 rear side housing side plate 6 rotor 8 compression chamber 9 rear housing 11 oil separator 12 discharge port 14 discharge chamber 18 first discharge port 20 second discharge port 21 silence passage 30 cavity

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F04C 29/06 F04C 18/344

Claims (1)

(57) [Claims] 1. A cylinder closed on both end surfaces of a housing by a front housing side plate and a rear housing side plate having one or a plurality of first discharge ports for allowing refrigerant gas to pass therethrough, and a shaft in the cylinder. a rotor which is supported to rotate, and one or a plurality of compression chambers which are partitioned and formed by the outer peripheral surface of the rotor and the inner peripheral surface of the cylinder, the compressed
In order to discharge the refrigerant gas pressurized in the chamber,
One or a plurality of cylinder discharge ports disposed, and the cylinder;
One end is fastened to the discharge surface of the discharge port so that one end can be opened and closed freely.
And an oil valve fixed to an outer end surface of the rear housing side plate and having one or a plurality of second discharge ports for discharging the refrigerant gas discharged from the cylinder discharge port and separating oil in the refrigerant gas. In a gas compressor provided with a discharge chamber defined by a separator, the rear housing side plate, and a rear housing fixed to a peripheral end surface of the rear housing side plate, an outer end surface of the rear housing side plate or the oil is provided. the Lee from one or a plurality of the first discharge port of the rear-side housing side plate at the inner end surface of the separator to one or more of the second discharge port of the oil separator
The open area when the valve is fully open is defined as the cross-sectional area of the passage.
A gas compressor characterized by having a noise reduction passage arranged.