JPH07139463A - Reciprocating compressor - Google Patents

Abstract

PURPOSE:To reduce suction pulse due to pressure loss by arranging an intake passage communicated with a suction chamber perpendicularly to an machine axis, varying a sectional area of the intake passage for forming a pulse attenuation part, and thereby equalizing pressure of coolant gas to be suctioned by a plurality of bores. CONSTITUTION:A cylinder head 20 is installed on a cylinder block 1 in which a plurality of bores 2 are parallely formed through a valve plate 5 which has suction ports 3 and discharge ports 4 correspondingly to the bores 2. When pistons 7 inserted into the respective bores 2 reciprocate with specified phase differences, coolant gas is suctioned into a suction chamber 9, comproessed in the bores 2, and discharged to a discharge chamber 8. An expanded portion 20a is formed on a side end wall of a cylinder head 20, while an intake passage 21 extended in a direction perpendicular to a machine axis is formed thereinside. A pulse attenuation part composed of the expanded portion 21a and a contracted portion 21b is formed in the intake passage 21, and is communicated with each area in the suction chamber through branch ports 21c, 21c'.

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 air conditioning of a vehicle, and more particularly to a multi-cylinder reciprocating compressor having a single-headed piston therein.

[0002]

2. Description of the Related Art Conventionally, as this main compressor, a constant capacity type compressor having a fixed swash plate and a variable capacity type compressor having a rotary swash plate capable of tilting displacement have been known. As shown in FIGS. 5 and 6, these compressors include a cylinder block 1 having a plurality of bores 2 arranged in parallel, a valve plate 5 having an intake port 3 and a discharge port 4 corresponding to each bore 2. And a cylinder head 6 for closing the outer end of the cylinder block 1 with the valve plate 5 having the intake valve 3a and the discharge valve 4a mounted therebetween.
The piston 7 inserted into each bore 2 is configured to reciprocate with a predetermined phase difference. Inside the cylinder head 6, a discharge chamber 8 is defined in the central region, and a suction chamber 9 is defined in the outer peripheral region.
Of the suction flange 12 of the suction chamber 9
Is communicated with the suction hole 13.

Therefore, when the compressor is driven, the refrigerant gas introduced from the circuit pipe connected to the evaporator into the suction chamber 9 through the suction hole 13 is in the process of being sequentially suctioned through the respective suction ports 3. The refrigerant gas sucked into the bore 2 and compressed is sequentially discharged from each discharge port 4 into the discharge chamber 8 and is discharged to the circuit pipe connected to the condenser via the discharge hole 11.

[0004]

However, as clearly shown in FIG. 5, the shape of the suction chamber is often complicated due to design restrictions and the like. An unexpectedly large pressure difference occurs between the position and the position farthest from the opening due to the pressure loss due to the gas flow. p. At a rotational speed of m, the value reaches 0.5 to ¹ kg / cm ² . For this reason, the refrigerant gas is always sucked as much as the bore corresponding to the suction port remote from the suction hole opening, which not only lowers the volumetric efficiency but also causes the nonuniform suction of the related device due to the suction pulsation. Amplifies vibration and noise.

As a matter of course, as a measure for reducing such suction pulsation, a technique of providing a muffler effect by partitioning the suction chamber in the axial direction by a partition wall (Actual No. 61-145884).
No.), and a technique in which a cover member is further mounted on the outer end of the cylinder head so that the entire circular expansion space formed inside functions as a muffler, depending on the difference between suction and discharge. 56-44481) and the like have been proposed.

However, all of these proposals have a structure in which the volume expanding portion of the gas flow path is provided in the axial direction of the compressor, and particularly in a vehicle air-conditioning compressor which is strongly demanded to be miniaturized, the expansion of the axial length is severely limited. In addition, attenuation of the pulsation component of about 500 to 800 Hz caused by the pulsation of the intake valve has a completely contradictory functional restriction that the extended muffler needs to have a length of at least 50 mm or more.

Further, like the latter proposed technique described above,
If the suction muffler is configured to have an expansion space that covers almost the entire end surface of the cylinder head, the area adjacent to the expansion space and the discharge chamber (high temperature region) will inevitably be expanded, so that the intake gas is heated. This may lead to new defects such as performance degradation. SUMMARY OF THE INVENTION The present invention aims to simultaneously attenuate the intake pulsation based on the pressure loss and the intake pulsation based on the pulsation of the intake valve as a technical problem to be solved.

[0008]

In order to solve the above problems, the present invention solves the above problems by providing a cylinder block in which a plurality of bores are arranged side by side, a valve plate having an inlet and an outlet corresponding to each bore, an inlet valve and an outlet. A piston inserted into each of the bores, which includes a cylinder head that closes the outer end of the cylinder block with the valve plate fitted with a valve interposed therebetween, and an intake chamber and a discharge chamber that are defined in the cylinder head. In a compressor of the type that reciprocates with a predetermined phase difference, while arranging a suction passage that connects a suction flange connected to a refrigeration circuit and a plurality of regions in the suction chamber in a direction orthogonal to the machine axis,
A novel structure is adopted in which the pulsation damping portion is formed by expanding or contracting the cross-sectional area of the suction passage.

In a preferred form of the present invention, the suction passage is communicated with at least two regions radially suspended in the suction chamber via a branch hole.

[0010]

When the compressor is driven, the refrigerant gas that has flowed into the suction chamber from the suction flange connected to the refrigeration circuit through the suction passage and the branch hole that forms a part of the suction passage is brought to a close position from each branch hole. Each bore is smoothly sucked through the open suction port, and the pressure loss due to the flow path resistance in the suction chamber is reasonably reduced, so the pulsation of relatively low frequency components accompanying the pressure loss is incidental. Will be reduced.

Further, a pulsation damping portion consisting of an expansion portion and a contraction portion is formed in the suction passage, and the expansion portion extends in a direction orthogonal to the axial center of the machine body, so that the axial length of the compressor is reduced. Since a necessary and sufficient length can be secured without causing a great influence, the pulsation of a relatively high frequency component due to the vibration of the suction valve is also damped very well.

[0012]

Embodiments of the present invention will be specifically described below with reference to FIGS. The same components as those of the conventional device are designated by the same reference numerals, and detailed description thereof will be omitted. That is, a substantially T-shaped bulging portion 20a is formed on the side end wall of the cylinder head 20 that closes the outer end of the cylinder block 1 with the valve plate 5 interposed therebetween, and the bulging portion 20a is formed inside thereof and is orthogonal to the axis of the machine body. A suction passage 21 extending in the direction of rotation is provided.
As is apparent from FIGS. 3 and 4, the suction passage 21 includes an expanded portion 21a having a long hole-shaped cross section and a reduced portion 21b having a circular cross section.
And a pulsation damping portion formed by
Each of the a and the reduced portion 21b similarly constitutes a part of the suction passage 21, and the branch hole 21 penetrating the bottom wall of the suction chamber 9 is formed.
It is communicated with two regions in the suction chamber 9 suspended from each other via c and 21c '. The opening end of the expanded portion 21a is covered with a suction flange 23 so as to accommodate the sealing element 22, and a suction hole 24 of the suction flange 23 connected to the suction passage 21 extends from an evaporator (not shown). It is connected to the suction system refrigeration circuit.

Therefore, in each of the bores 2 in which the compressor is driven to sequentially move to the suction stroke, the corresponding suction port 3 and each branch hole 21 opened at a position close to the suction port 3 are provided.
Since the refrigerant gas is smoothly sucked through c and 21c 'and the pressure loss due to the flow path resistance in the suction chamber 9 is reasonably reduced, the pulsation of the relatively low frequency component accompanying the pressure loss is incidental. Is reduced to.

In particular, in the suction passage 21 of the present invention, the pulsation damping portion consisting of the expanded portion 21a and the contracted portion 21b functions as a muffler, and the expanded portion 21a is oriented in the direction orthogonal to the axial center of the machine body. It is possible to secure a necessary and sufficient length without extending so much that the axial length of the compressor is greatly affected. Therefore, the pulsation of a relatively high frequency component due to the vibration of the suction valve 3a is also well damped. It

In the above-described embodiment, the branch hole 21 through which the refrigerant gas communicates with the two regions in the suction chamber 9 which are suspended from each other.
Although the structure in which the air is sucked through c and 21c 'has been described, if it is communicated with another region in the suction chamber 9 through a branch hole further extended from a part of the suction passage 21, it is sucked into each bore 2. The pressure difference of the refrigerant gas can be further equalized. It is also possible to locally increase the depth of the suction chamber 9 and directly open the reduced portion 21b of the suction passage 21 on the inner peripheral wall thereof so as to omit the illustrated branch hole 21c '.

[0016]

As described above in detail, according to the present invention, the suction passage that connects the suction flange connected to the refrigeration circuit and the plurality of regions in the suction chamber is arranged in the direction orthogonal to the machine axis. Since the pulsation damping portion is formed by expanding / contracting the cross-sectional area of the suction passage, the pressure difference of the refrigerant gas sucked into each bore is equalized, and the suction pulsation due to the pressure loss is reasonably reduced. At the same time, due to the function of the pulsation attenuating portion formed in the suction passage, it is possible to extremely well dampen the heterogeneous pulsation component generated due to the vibration of the suction valve.

[Brief description of drawings]

FIG. 1 is a sectional side view showing a rear housing of a compressor according to an embodiment of the present invention.

FIG. 2 is a sectional front view showing a suction passage of the compressor according to the embodiment of the present invention.

FIG. 3 is a side view showing a suction passage of the compressor according to the embodiment of the present invention.

FIG. 4 is a view taken along the line AA of FIG. 3 showing the suction passage of the compressor according to the embodiment of the present invention.

FIG. 5 is a sectional side view showing a rear housing of a conventional compressor.

FIG. 6 is a sectional front view showing a rear housing of a conventional compressor.

[Explanation of symbols]

1 is a cylinder block, 2 is a bore, 3 is a suction port, 3a is a suction valve, 5 is a valve plate, 8 is a discharge chamber, 9 is a suction chamber, 20 is a cylinder head, 21 is a suction passage, 21a is an expansion part, 21
b is a reduced portion, 21c and 21c 'are branch holes, 23 is a suction flange, and 24 is a suction hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masafumi Ito 2-chome, Toyota-cho, Kariya City, Aichi Stock Company Toyota Industries Corp.

Claims (2)

[Claims] 1. A cylinder block having a plurality of bores arranged in parallel, a valve plate having an intake port and a discharge port corresponding to each bore, and the cylinder block sandwiching the valve plate having the intake valve and the discharge valve mounted therein. A compressor of a type that includes a cylinder head that closes the outer end of the cylinder, and a suction chamber and a discharge chamber that are defined in the cylinder head, and a piston that is inserted into each of the bores reciprocates with a predetermined phase difference. In the pulsation damping unit, a suction passage that connects the suction flange connected to the refrigeration circuit and a plurality of regions in the suction chamber is arranged in a direction orthogonal to the machine body axis, and the cross-sectional area of the suction passage is expanded or reduced. A reciprocating compressor characterized by being formed. 2. The reciprocating compressor according to claim 1, wherein the suction passage is in communication with at least two radially suspended regions in the suction chamber via a branch hole.