JPH062654A - Compressor - Google Patents

Abstract

PURPOSE:To reduce the extent of noise and vibration attending on opening or closing a discharge valve in a compressor. CONSTITUTION:A wedge type notch 37, by way of example, being interconnected to an interspace in a discharge port 18 even in a valve closed state is installed within the range of a contact surface of a discharge valve 16 (illustration is a reed valve) at an end face downstream of this discharge port 18 being opened to a valve plate 3 of a compressor. Since pressure in a fluid compressed in an operating chamber 14 acts on not only a sectional area of the discharge port 18 but also an area of the notch 37, force for opening the discharge valve 16 becomes large enough as compared with the case that it is not installed, while an overcompression value necessary for opening the discharge valve 16 beyond the discharge pressure becomes lessened. In consequence, noise and vibration attending on opening or closing the discharge valve 16 is reduced, and a torque variation and a power increase for driving the valve are also restrained, thus temperature in the fluid to be discharged goes down. In this connection, a figure 20 shows minute jogs by dint of a shot blast performed from the past and 19 shows a valve guard, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor suitable for compressing a refrigerant in, for example, an automobile air conditioner, and more particularly to a discharge valve used in the compressor.

[0002]

2. Description of the Related Art In recent years, in order to improve the quietness and comfort of an automobile, research on a technique for suppressing noise generated by a vehicle body and an internal combustion engine mounted on the automobile has been advanced, and the level of noise and vibration is reduced as a whole. Since they are decreasing, noise and vibration of auxiliary equipment parts, which were not a problem when they were at a high level, became noticeable, and the development of technology to suppress them became an urgent task. It was As a problem among the noises of such auxiliary equipment parts, a refrigerant compressor of an automobile air conditioner, in particular, a discharge port for discharging a compressed refrigerant from a working chamber toward a condenser of a refrigeration circuit is provided. There is pulsating noise generated when the discharge valve having a shape such as a reed valve intermittently opens and closes the discharge port.

A reed valve that automatically opens and closes depending on the pressure difference is often used as the discharge valve of the refrigerant compressor. The reed valve is made of a metal having elasticity so as to close the outside of the discharge port that is opened in the valve plate. Since the thin plate (lead) is attached in a cantilevered manner, the reed normally blocks the discharge port, and the pressure in the working chamber increases when the pressure in the working chamber of the compressor rises. When the valve opening force multiplied by the value reaches a value that allows the lead to bend and deform toward the valve opening side,
The reed bends, opens the discharge port rapidly, and opens the valve.
At that time, the refrigerant compressed in the working chamber is ejected into the discharge chamber so as to burst, which causes noise.

When such a discharge valve is opened, the discharge valve that is normally closed is opened, so the pressure in the working chamber of the compressor is the same as the pressure in the discharge chamber outside the discharge valve. The valve does not open only when the value is reached, but when the valve opening pressure, which is higher than the discharge pressure and which is mainly determined by the rigidity of the reed, is reached, the reed is opened to open the valve. This excess pressure is generally called an overcompression amount, and in order to discharge the compressed fluid to the discharge chamber, the compressor needs to additionally compress the compressed fluid such as a refrigerant. When the amount of over-compression increases, not only noise, vibration, torque fluctuations, etc. increase, but also the temperature of the discharged fluid (discharge temperature) rises, and the power required to drive the compressor also increases. It is well known that many adverse effects occur.

[0005]

As a means for reducing the amount of over-compression, shot blasting has been conventionally performed on the surface of the valve plate around the discharge port with which the lead of the discharge valve comes into contact, and a smooth surface is formed. Therefore, it is done to intentionally add minute unevenness. It is also true that this has the effect of reducing the amount of over-compression, but when the compressor is used for a long period of time and the number of collisions of the reed with the valve plate becomes extremely large, the reed even on the valve plate surface will be affected. On the seating surface of No. 3, there was a problem that minute unevenness due to shot blast was gradually worn away to reduce the surface roughness, the effect of unevenness was lost, and noise and vibration were increased. In view of these problems of the prior art, it is an object of the present invention to provide a novel means for reducing noise and vibration of a compressor very easily and maintaining their effects. .

[0006]

DISCLOSURE OF THE INVENTION The present invention is, as a means for solving the above-mentioned problems, a discharge capable of automatically opening a valve toward a discharge chamber in accordance with the pressure of a fluid compressed in a working chamber. A valve, a discharge port formed from the working chamber through the discharge valve to the discharge chamber and having a downstream end face closed by the discharge valve, and the discharge valve at the downstream end face of the discharge port. A compressor provided with a notch formed within a range of a contact surface and always communicating with a space inside the discharge port.

[0007]

In the range of the contact surface of the discharge valve on the downstream end face of the discharge port, a notch communicating with the space inside the discharge port is provided even when the valve is closed. It affects not only the cross-sectional area of the outlet but also the area of the notch. Therefore, the force for opening the discharge valve becomes larger than that in the case where the notch is not provided, and the amount of over-compression required to open the discharge valve beyond the discharge pressure becomes small. As a result, noise and vibration associated with the opening and closing of the discharge valve are reduced, and torque fluctuation and power increase for driving are also suppressed.
The temperature of the discharged fluid decreases.

[0008]

EXAMPLE FIG. 2 shows a swash plate type compressor as an example of the present invention. The cross-sectional shape along the line AA is shown in FIG. 1, which shows the shape of the surface of the valve plate including the main part B of this embodiment. The cross-sectional shape of the main part B of this embodiment is enlarged and shown in FIGS. 3 and 4. The main body of the swash plate type compressor 1 shown in FIG.
And a front housing 4 fastened on the left side with the valve plate 3 sandwiched therebetween, and a rear housing 6 fastened with the valve plate 5 sandwiched on the right side. The cylinder block 2 at the center of the main body is further divided into two parts, a front side cylinder block 2a and a rear side cylinder block 2b. Further, five through bolts 7 are used as means for integrally fastening the cylinder blocks 2a and 2b, the valve plates 3 and 5, the front housing 4 and the rear housing 6.

Inside the front housing 4, a substantially annular suction chamber 8 is located near the inner circumference and a substantially annular discharge chamber 9 is located near the outer circumference.
Similarly, inside the rear housing 6, a substantially annular suction chamber 10 is formed near the inner circumference and a substantially annular discharge chamber 11 is formed near the outer circumference. The suction chamber 8 on the front side and the suction chamber 10 on the rear side are in communication with each other, and as a fluid to be compressed, a return refrigerant is supplied from, for example, an evaporator in a refrigeration circuit of an air conditioner. Further, the front side discharge chamber 9 and the rear side discharge chamber 11 are also in communication with each other, and a fluid such as a compressed refrigerant is merged and sent to, for example, a condenser in a refrigeration circuit of an air conditioner.

On the front cylinder block 2a,
Five cylinders 12 are bored at even positions around the center, and correspondingly, the rear cylinder block 2b also has five cylinders 12 on the same axis as the pair. A cylinder 13 is bored. A common piston is inserted into each of the paired cylinders on the front side and the rear side so as to bridge the cylinders, and a working chamber 14 is provided in each of the five front side cylinders 12. Further, working chambers 15 are formed in the five rear cylinders 13, respectively.

The valve plate 3 on the front side is provided with a working chamber 14 in each cylinder 12 and a common annular discharge chamber 9.
And a reed valve-shaped discharge valve 16 made of a thin spring plate, respectively, and closed from the outside (left side in FIG. 2) of the valve plate 3. Reference numeral 19 exemplifies one of the valve retainers for the discharge valve provided at the discharge port 18. On the outer side surface of the valve plate 3, as shown in FIG. 1, the annular portion 20 on which the discharge valve 16 is seated so as to close the discharge port 18 is provided with fine irregularities by shot blasting.

Similarly, the valve plate 5 on the rear side is also provided with a discharge port 21 through which the working chamber 15 in each cylinder 13 and a common discharge chamber 11 having a substantially annular shape can communicate with each other, and each thin spring plate. Is closed from the outside (right side in FIG. 2) of the valve plate 5. Although not shown in the drawing, a ring-shaped portion having fine irregularities formed by shot blasting is also provided around the discharge port 21 outside the valve plate 5 as in the front side. In addition, 22 has illustrated one of the valve retainers.

A rotary shaft 24 extends from a side surface into a swash plate chamber 23 formed in the cylinder block 2 and is rotationally driven from an internal combustion engine of a vehicle (not shown) via an electromagnetic clutch or a transmission device such as a transmission. It The rotary shaft 24 is supported by radial bearings 25 and 26 provided in the cylinder block 2 in the front and rear thereof. In the swash plate chamber 23, an elliptical swash plate 27 is attached to and integrated with the rotary shaft 24 by an appropriate means, and the axial load as a reaction force acting on the rotary shaft 24 by the swash plate 27 is It is supported by a pair of thrust bearings 28 and 29.

A double-headed piston 3 is provided in each pair of the front-side cylinder 12 and the rear-side cylinder 13 which are bored in the cylinder block 2 in parallel with the rotary shaft 24.
0 is inserted so as to be reciprocally slidable in the axial direction, and spherical recesses 31, for example, are formed on both side walls of the groove in the central portion of the pistons 30. A pair of wear resistant shoes 32 forming a part of the above are inserted, and the peripheral portion of the swash plate 27 is slidably sandwiched between the shoes 32.

The swash plate chamber 23 is used as a part of the suction passage of the swash plate type compressor 1. As described above, both the front suction chamber 8 and the rear suction chamber 10 communicate with the swash plate chamber 23. The low-temperature low-pressure refrigerant returning from, for example, the evaporator in the refrigerating circuit of the air conditioner is received by the suction pipe (not shown) connected to the swash plate chamber 23.

The front suction chamber 8 and each cylinder 12
Of the valve plate 3 between the working chamber 14 and the suction port 33
An intake valve 34 made of an elastic thin metal plate (lead) is provided inside the valve plate 3 (on the right side in FIG. 2) to close the intake port 33 from the inside. Similarly, the suction chamber 10 on the rear side and each cylinder 1
The valve plate 5 between the working chamber 15 and the working chamber 15 has a suction port 3
5 is perforated, and an intake valve 3 made of an elastic thin metal plate is provided inside the valve plate 5 (on the left side in FIG. 2).
6 is provided to close the suction port 35 from the inside.

Although the above-mentioned structure is not particularly different from the conventional compressor, the compressor of the illustrated embodiment is enlarged and clearly shown in FIGS. 3 and 4 in correspondence with the feature of the present invention. In addition, a notch 37 is formed in a part of the outer peripheral edge (on the side of the discharge chamber 9) of the discharge port 18 that is bored in the valve plate 3. The notch 37 in this example is like a wedge-shaped shallow groove, and has a shape in which the depth gradually decreases toward the tip P. The notch 37 does not need to penetrate the valve plate 3, and at the same time when the discharge port 18 is punched out on the surface of the valve plate 3 covered by the reed-shaped discharge valve 16, for example, by a projection formed on the tool, It is formed. Although the rear valve plate 5 is shown in a small size in FIG. 2 and not shown in detail, the notch 37 as shown in FIGS. 3 and 4 is provided in the discharge port of the rear valve plate 5. The same applies to 21 as well.

The desired size of the notch 37 is such that its tip P does not reach the starting point of the deflection of the discharge valve 16, that is, the holding portion 38 of the front housing 4, and its width is as shown in FIG. Due to the relationship with the width of 16, it is set so that the sealed portion remains about 2 mm. The depth of the groove is, for example, about 0.2 to 0.5 mm at the deepest point.
If the depth is excessively large, the dead volume of the working chamber 14 is increased and the compression function is deteriorated.

The basic operation of the swash plate type compressor 1 of the illustrated embodiment is similar to that of the conventional swash plate type compressor, and when the rotary shaft 24 is driven to rotate, the swash plate 27 rotates. It swings and gives a reciprocating motion in the axial direction to the piston 30 via the shoe 32. As a result, the front working chamber 14 and the rear working chamber 15 that are paired with each other alternately expand and contract, and compress the fluid such as the refrigerant sucked through the suction ports from the suction chambers 8 and 10. The fluid pressurized in the working chamber 14 or the working chamber 15 is discharged from the discharge ports 18 and 21 to the discharge valve 16
And 17 are pushed open and ejected into the discharge chambers 9 and 11, and after being merged, they are guided to a condenser in a refrigerating circuit of an air conditioner through a passage (not shown).

When a fluid such as the refrigerant in the working chamber 14 or the working chamber 15 is compressed by the piston 30, the pressure of the compressed fluid depends on the size of the cross-sectional area of the discharge port 18 or 21. 16 or 17 acts on the surface (inner surface) to generate a force in the valve opening direction.
Or, the discharge valve 16 or 17 does not open only by exceeding the adhesion force pressing the valve plate 3 or 5 against the valve plate 3 or 5, and the fluid is further strongly compressed by the piston 30 and the discharge valve 16 or 17 is further compressed. Or, since it is necessary to bend it against the elastic force of the discharge valve 16 or 17 so as to take a gap necessary for passage of fluid, the maximum pressure value generated at that time and the discharge pressure The difference is generally referred to as "overcompression amount", and that when the overcompression amount increases, noise, vibration, and torque fluctuations of the compressor increase, leading to an increase in discharge temperature and an increase in power required for driving. However, the magnitude of this overcompression amount depends on the ease with which the discharge valve opens.

In the case of the embodiment of the present invention, the valve plate 3
Since the cutouts 37 are provided in the and 5, the pressure fluid in the working chamber 14 or 15 not only acts on the discharge valve 16 or 17 over the region corresponding to the cross-sectional area of the discharge port 18 or 21, but also the cutout 37. Since it wraps around the surface of the discharge valve 16 or 17 more widely and acts on the area corresponding to the size of the notch 37, the effective area on the discharge valve 16 or 17 on which the fluid pressure acts increases. And discharge valve 1
The force that pushes 6 or 17 in the valve opening direction becomes large and the discharge valve 1
6 and 17 are easy to open.

Therefore, when the notch 37 is provided, the discharge valves 16 and 17 are opened even if the value of the pressure exceeding the discharge pressure is small as compared with the case where the notch 37 is not provided. This relationship is shown by the P-V diagram of FIG. In FIG. 5, the horizontal axis indicates the volume V of the working chamber 14 or 15, and the vertical axis indicates the working chamber 14.
Or, the pressure P of 15 or 15 is taken to show the change of the pressure of the working chamber 14 or 15 with respect to the stroke of the swash plate type compressor. There is a clear difference between the case and the case of the conventional example (where the notch 37 is not provided) indicated by the broken line. That is, the overcompression amount Pt according to the embodiment of the present invention does not have a peak value like the overcompression amount Pt ′ according to the conventional example, and the height is low on average.

By thus reducing the amount of over-compression, noise, vibration, torque fluctuation, etc. can be actually reduced, and effects such as a decrease in discharge temperature and a decrease in power required for driving can be obtained. Is also confirmed by experiments by the inventors. Since the depth of the notch 37 is deeper than the fine unevenness formed by the shot blasting process on the annular portion 20 of the surface of the valve plates 3 and 5, even if the discharge valves 16 and 17 are repeatedly contacted for a long period of time, they are worn away. Even if the effect of the annular portion 20 is reduced by abrasion, the effect of reducing noise and the like continues if the notch 37 is also provided.

FIG. 6 shows the level of noise generated by comparing the conventional ordinary swash plate type compressor with the case where the notch 37 is provided in the discharge port of the valve plate (the present invention). It is a thing. In any case, since the fine irregularities provided by the shot blasting process are worn away with time, the noise level gradually increases, but the noise reduction effect of the notch 37 is remarkable.

Although the present invention has been described by taking the swash plate type compressor 1 having the reed valve type discharge valves 16 and 17 as an example, the object of providing the notch 37 is the valve of the swash plate type compressor 1. Since the invention is not limited to the plate 3 or 5, it is considered that the present invention can be applied to a compressor having a discharge valve in general. Regarding the shape of the notch 37, it is formed as a wedge-shaped groove in the illustrated embodiment, but it may be another shape instead of the wedge shape as long as it has the same action and effect. The width of the groove of the notch 37, etc. is made as large as possible as long as the sealing property of the discharge valve 16 or 17 is sufficiently secured and the increase of the dead volume of the working chambers 14 and 15 can be ignored. be able to.

[0026]

According to the present invention, noise and vibration generated from the compressor can be reduced by a very simple means of providing a notch on the downstream end surface of the discharge port of the discharge valve. It is possible to prevent torque fluctuation and power increase for driving, and lower the temperature of the discharged fluid. There is no need to insert a special step to provide the notch, and since it is possible to perform processing at the same time in the step of punching the discharge port and the processing is extremely simple, there is no increase in cost due to the implementation of the present invention. . Since the notch according to the present invention is not likely to be worn away like the fine irregularities formed by the conventional shot blasting, the effect is stably maintained for a long time.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional front view showing the overall configuration of the embodiment of FIG.

FIG. 3 is a side sectional view showing an enlarged main part of FIG.

FIG. 4 is a front sectional view of a main part shown in FIG.

FIG. 5 is an actual measurement P for explaining the operation and effect of the present invention.
It is a -V diagram.

FIG. 6 is a diagram showing the noise reduction effect of the present invention in comparison with a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Swash plate type compressor 2 ... Cylinder block 3, 5 ... Valve plate 9, 11 ... Discharge chamber 14, 15 ... Working chamber 16, 17 ... Discharge valve 18, 21 ... Discharge port 23 ... Swash plate chamber 24 ... Rotation shaft 27 … Swash plate 30… Double-headed piston 37… Notch 38… Holding part

Claims (1)

[Claims] 1. A discharge valve capable of automatically opening toward a discharge chamber according to the pressure of a fluid compressed in the working chamber, and a discharge from the working chamber through the discharge valve to the discharge chamber. A discharge port which is formed as a passage and whose downstream end face is closed by the discharge valve, and a discharge port which is formed in the range of the contact surface of the discharge valve on the downstream end face of the discharge port and is always in communication with the space in the discharge port. A compressor provided with a notch.