JPH0791369A - Multistage reciprocating compressor - Google Patents

Abstract

PURPOSE:To prevent any cloudy phenomenon in lubricating oil from occurring by forestalling a drain flowing into a high-pressure side cylinder from a suction chamber of a cylinder head. CONSTITUTION:A cylinder head 21 is installed on a high-pressure side cylinder 9 so as to make a suction chamber 22 turn to the lower side and a discharge chamber 23 to the upper side respectively, and an inlet port 22B of the suction chamber 22 is set up so as to make it downward and to be opened to a bottom side (nearer to the cylinder 9), while a high-pressure side pipe part 24C of an intermediate pipeline 24 is connected to the inlet port 22B so as to extent it downward as its constitution. Accordingly, in time of the shutdown of a compressor, each drain produced in the suction chamber 22 and the intermeduate pipeline 24 is all flowing into the side of the intermediate pipeline 24 from the inside of the suction chamber 22 via the inlet port 22B set up at the bottom side, and it is conducted to the side of an intermediate pipe part 24B to be situated at the lower side together with another drain produced in the intermediate pipeline 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-stage reciprocating compressor suitable for efficiently compressing a fluid such as air.

[0002]

2. Description of the Related Art A two-stage reciprocating air compressor will be described as an example of a conventional multi-stage reciprocating compressor with reference to FIGS.

In the drawing, 1 is a crankcase which constitutes the main body of a reciprocating air compressor, and 2 is a crankshaft whose one end is rotatably disposed in the crankcase 1 via a bearing (not shown). The other end of the crankshaft 2 projects out of the crankcase 1, and a pulley 18 to be described later is attached to the projecting end. Further, the crankcase 1 has a pair of oblique sides 1A, 1A on the upper side.
Is formed as a mountain-shaped closed box, and the lubricating oil A for lubricating and cooling each sliding portion and the like is housed therein.

Reference numeral 3 denotes a low-pressure side cylinder which is located on the left side of the crankcase 1 in the drawing and has a predetermined inclination to the left, and on the cylinder 3, an upper opening of the cylinder 3 is provided. A cylinder head 4 that closes the cylinder is mounted. Here, the inside of the cylinder head 4 is, as shown in FIG. 4, one end side of the cylinder 3 via a suction valve (not shown).
It becomes a suction chamber 5 that can communicate with the inside, and the other end side is a discharge chamber 6 that can communicate with the inside of the cylinder 3 via a discharge valve (not shown). Further, the suction chamber 5 is formed with a suction port 5A located at one end side and opening toward one side to suck air as a fluid in the suction chamber 5, and the discharge chamber 6 has the other end. A discharge port 6A that is located on the side and opens toward the other side to discharge the compressed air discharged into the discharge chamber 6 to the outside,
A filter (not shown) is attached to the suction port 5A, and a low-pressure side pipe portion 15A of an intermediate pipe 15 described later is connected to the discharge port 6A.

Reference numeral 7 denotes a piston which is reciprocally inserted into the cylinder 3, and 8 denotes a connecting rod which has a base end side connected to the crankshaft 2 and a front end side connected to the piston 7 via a piston pin 7A. The connecting rod 8 has its base end side rotated by the crankshaft 2 to reciprocate the piston 7 connected to the tip end side in the cylinder 3.

Reference numeral 9 designates a cylinder on the high pressure side, which is located on the hypotenuse 1A on the right side of the crankcase 1 in the figure, is provided with a predetermined inclination to the right, and has a diameter smaller than that of the cylinder 3 on the low pressure side. , A cylinder head 1 on the cylinder 9.
0 is installed. Here, in the cylinder head 10, an upper left end side is a suction chamber 11 that can communicate with the inside of the cylinder 9 through a suction valve 11A, and a lower right end side is communicated with the inside of the cylinder 9 through a discharge valve 12A. It is a possible discharge chamber 12. Further, the suction chamber 11 is formed with a suction port 11B which is located on the upper end side and opens obliquely upward and sucks air into the suction chamber 11, and the discharge chamber 12 is located on the lower end side. And a discharge port 12B which is opened obliquely downward and discharges the compressed air discharged into the discharge chamber 12 to the outside, and the intermediate pipe 15 is provided at the suction port 11B.
15C of the high-pressure side is connected, and the discharge port 12B is connected to a discharge pipe 16 described later.

Reference numeral 13 denotes a piston which is reciprocally inserted into the cylinder 9, and 14 has a base end side connected to the crankshaft 2 and a front end side which is connected to the piston pin 13A through the piston pin 13A.
3 shows connecting rods connected to each other.
Is rotated by the crankshaft 2 on the base end side, so that the piston 13 connected to the tip end side is moved to the cylinder 9
It reciprocates inside.

Reference numeral 15 denotes an intermediate pipe provided between the low pressure side cylinder head 4 and the high pressure side cylinder head 10. The intermediate pipe 15 has a discharge end formed at the low pressure side cylinder head 4 at the base end side. A low-pressure side pipe portion 15A, which is connected to the discharge port 6A of the chamber 6 and whose tip side extends downward, and extends rightward from the tip side of the low-pressure side pipe portion 15A so as to pass under the crankshaft 2. The intermediate pipe portion 15B and the suction port 11B of the suction chamber 11 formed in the cylinder head 10 on the high-pressure side are bent upward and extend upward from the tip side of the intermediate pipe portion 15B. High pressure side tube 1
5C and is formed in a substantially U-shape opening upward. The intermediate pipe 15 supplies the compressed air discharged from the discharge chamber 6 of the low pressure side cylinder head 4 to the suction chamber 11 of the high pressure side cylinder head 10.

Reference numeral 16 denotes a discharge pipe connected to the discharge port 12B of the discharge chamber 12 formed in the cylinder head 10 on the high pressure side, and the tip end side of the discharge pipe 16 is connected to an air tank (not shown). The compressed air discharged from the discharge chamber 12 is discharged into the air tank.

Reference numeral 17 denotes an oil scraper located in the crankcase 1 and provided on the base end side of one of the connecting rods 8 and 14. The oil scraper 17 is such that the crankshaft 2 is driven to rotate. The lubricating oil A in the crankcase 1 is swept up by the above-mentioned operation to supply oil to each sliding portion.

On the other hand, reference numeral 18 denotes a pulley mounted on the protruding end side of the crankshaft 2, and the pulley 18 is rotated by a rotation source (neither is shown) via a belt, whereby the crankshaft 2 is rotated. Is to rotate.

The two-stage reciprocating air compressor according to the prior art has the above-mentioned structure, and when the crankshaft is rotationally driven by the drive source, the piston 7 is in the low pressure side cylinder 3 via the connecting rod 4. And the piston 13 is reciprocated in the high pressure side cylinder 9 via the connecting rod 14. This allows the suction chamber 5 to pass through the filter.
The air sucked in is sucked into the low pressure side cylinder 3 via the suction valve, is compressed to an intermediate pressure in the cylinder 3 and is discharged into the discharge chamber 6 via the discharge valve. The compressed air discharged into the discharge chamber 6 has a discharge port 6A.
Is supplied into the suction chamber 11 through the intermediate pipe 15.
Next, the compressed air supplied into the suction chamber 11 is supplied to the suction valve 1
1A is sucked into the high-pressure side cylinder 9, compressed to the final pressure in the cylinder 9, and then discharged into the discharge chamber 12 through the discharge valve 12A. From the discharge chamber 12 through the discharge pipe 16. It can be stored in the air tank.

[0013]

The conventional two-stage reciprocating air compressor described above has, for example, 1 to
It may be used in a so-called ultra-intermittent operation state in which it is repeatedly operated for 2 minutes and stopped for 1 hour. When the operation is stopped in such an ultra-intermittent operation, the suction chamber 11 on the high-pressure side, the intermediate pipe 15, etc. are cooled to room temperature. Then, when the compression operation is restarted after a while, the compressed compressed air having a high temperature comes into contact with the cooled intermediate pipe 15 and the suction chamber 11 to cause dew condensation to generate a drain.

Further, the compressed air that has been increased to an intermediate pressure in the low pressure side cylinder 3 is stored under pressure in the suction chamber 11, the intermediate pipe 15 and the like of the high pressure side cylinder head 10, and in this state the compressed air is stored. Is cooled to almost room temperature, dew condensation occurs in the suction chamber 11 and the intermediate pipe 15 to cause drainage.

When the compression operation is restarted in the state where the drain is generated as described above, the drain in the suction chamber 11 and the intermediate pipe 15 is sucked into the cylinder 9 together with the compressed air through the suction valve 11A. The drain flows into the crankcase 1 from between the cylinder 9 and the piston 13. As a result, the drain is mixed into the lubricating oil A to cause a turbid phenomenon in the lubricating oil A, which not only shortens the life of the lubricating oil A but also reduces the rust preventive effect of the lubricating oil A, which causes rusting. There is a problem that the life of the compressor itself is significantly reduced.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to prevent the drain from flowing into the cylinder side of the high pressure side from the intermediate pipe to prevent the clouding phenomenon of the lubricating oil. A reciprocating air compressor is provided.

[0017]

In order to solve the above-mentioned problems, the structure of the multi-stage reciprocating compressor adopted by the present invention comprises a crankcase and a low pressure side cylinder mounted on the crankcase. A high-pressure side cylinder mounted on the crankcase with an inclination, a cylinder head mounted on each cylinder and having a suction chamber and a discharge chamber defined inside, and reciprocating in each cylinder. A piston for compressing the fluid sucked from the suction chamber of the cylinder head and discharging it to the discharge chamber side; a discharge chamber of the cylinder head on the low pressure side and a suction chamber of the cylinder head on the high pressure side. It consists of connecting intermediate piping.

The features of the configuration adopted by the present invention are as follows.
The cylinder head on the high pressure side is arranged on the high pressure side cylinder so that the suction port of the suction chamber opens downward,
The intermediate pipe is connected to the suction port of the suction chamber so as to extend downward.

[0019]

With the above structure, the drain generated in the suction chamber of the cylinder head on the high pressure side when the operation is stopped flows out into the intermediate pipe through the suction port opening downward, and flows downward together with the drain generated in the intermediate pipe. Then, it is guided to the lower end side of the intermediate pipe, and the drain is prevented from being stored in the suction chamber.

[0020]

Embodiments of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the conventional technique shown in FIGS. 3 to 5 are designated by the same reference numerals, and the description thereof will be omitted.

First, FIG. 1 shows a first embodiment of the present invention.

In the figure, reference numeral 21 denotes a cylinder head according to the present embodiment mounted on the cylinder 9 on the high pressure side. Inside the cylinder head 21, the lower right end is the suction valve 2
2A is a suction chamber 22 that can communicate with the inside of the cylinder 9, and the upper left end is a discharge chamber 23 that can communicate with the inside of the cylinder 9 via a discharge valve 23A. It's different. Further, the suction chamber 22 is formed with a suction port 22B located at the lower end side and opening obliquely downward and sucking air as a fluid into the suction chamber 22, and the discharge chamber 23 is provided with: A discharge port 23B that is located on the upper end side and opens obliquely upward and discharges the compressed air discharged into the discharge chamber 23 to the outside is formed.

Here, the suction port 22B is the suction chamber 22.
It is arranged so as to open on the bottom side (close to the cylinder 9), whereby all the drain generated in the suction chamber 22 flows out to the intermediate pipe 24 side described later. The suction port 22B is connected to the high-pressure side pipe portion 24C of the intermediate pipe 24, and the discharge port 23B is connected to a discharge pipe 25 described later.

Reference numeral 24 denotes an intermediate pipe according to the present embodiment provided between the low pressure side cylinder head 4 and the high pressure side cylinder head 21, and the intermediate pipe 24 is substantially the same as the intermediate pipe 15 described in the prior art. Similarly, the low pressure side pipe portion 24A connected to the discharge port 6A of the discharge chamber 6 formed in the low pressure side cylinder head 4 and the tip side of the low pressure side pipe portion 24A pass through the lower side of the crankshaft 2. Connected to the intermediate pipe portion 24B extending rightward to the right and the suction port 22B of the suction chamber 22 formed in the cylinder head 21 on the high pressure side extending upward from the tip end side of the intermediate pipe portion 24B. It is formed in a substantially U-shape that opens upward from the side tube portion 24C. However, the tip end side of the high-pressure side tube portion 24C is connected to the suction port 22B from below so as to extend downward from the suction port 22B, whereby the drain generated in the suction chamber 22 is discharged in the intermediate pipe 24. It is configured to be guided to the intermediate pipe portion 24B side together with the generated drain.

Reference numeral 25 denotes a discharge pipe connected to a discharge port 23B of a discharge chamber 23 formed in the cylinder head 21 on the high pressure side. The discharge pipe 25 is the same as the discharge pipe 16 described in the prior art. The compressed air discharged from the discharge chamber 23 is discharged into an air tank (not shown).

The two-stage reciprocating air compressor according to this embodiment has the above-mentioned structure, and its basic operation is not different from that of the prior art.

However, in this embodiment, the cylinder head 2
1 is arranged on the high pressure side cylinder 9 so that the suction chamber 22 is on the lower side and the discharge chamber 23 is on the upper side.
The suction port 22B of the suction port 22B facing downward and opening toward the bottom side (close to the cylinder 9).
Is connected to the high-pressure side pipe portion 24C of the intermediate pipe 24 so as to extend downward. Therefore, even if the drain is generated in the suction chamber 22 and the intermediate pipe 24 when the compressor is stopped, the entire amount of the drain is transferred from the suction chamber 22 to the intermediate pipe 24 side through the suction port 22B arranged on the bottom side. It can be made to flow out and be circulated downward together with the drain generated in the intermediate pipe 24 to be guided to the intermediate pipe portion 24B side.

Thus, according to the present embodiment, the drain generated in the suction chamber 22 and the intermediate pipe 24 of the cylinder head 21 on the high pressure side can be guided to the intermediate pipe portion 24B side, so that the drain is in the suction chamber 22. Stored in crankcase 1
It is possible to reliably prevent the oil from flowing into the inside, prevent the occurrence of the clouding phenomenon of the lubricating oil A due to the inflow of the drain, extend the life of the lubricating oil A, and prevent rusting. Therefore, the life of the compressor itself can be extended.

Next, FIG. 2 shows a second embodiment of the present invention, which is characterized in that the low pressure side cylinder head is arranged on the cylinder so that the discharge chamber is on the lower side. An intermediate pipe is connected to the discharge port of the discharge chamber so as to extend downward. In the embodiment, the same components as those in the first embodiment shown in FIG. 1 described above are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 31 indicates a cylinder head according to the present embodiment mounted on the cylinder 3 on the low pressure side. Inside the cylinder head 31, the suction valve 3 is located on the upper right side.
Conventionally, a suction chamber 32 that can communicate with the inside of the cylinder 3 via 2A is arranged, and a discharge chamber 33 that can communicate with the inside of the cylinder 3 via a discharge valve 33A is arranged on the lower left side. It differs from the cylinder head 4 according to the technology. Further, the suction chamber 32 is formed with a suction port 32B which is located on the upper end side and opens obliquely upward to suck air as a fluid in the suction chamber 32, and the discharge chamber 33 has a lower end. Located on the side of the discharge chamber 33 and opened obliquely downward.
A discharge port 33B for discharging the compressed air discharged into the outside
Are formed.

Here, the discharge port 33B is the discharge chamber 33.
Is arranged so as to open on the bottom side (close to the cylinder 3), whereby the entire amount of drain generated in the discharge chamber 33 flows out to the intermediate pipe 34 side described later. A filter (not shown) is connected to the suction port 32B, and the low pressure side pipe portion 34A of the intermediate pipe 34 is connected to the discharge port 33B.

Reference numeral 34 denotes an intermediate pipe according to the present embodiment provided between the low pressure side cylinder head 31 and the high pressure side cylinder head 21, and the intermediate pipe 34 is the intermediate pipe described in the first embodiment. Similar to 24, the low pressure side pipe portion 34A connected to the discharge port 33B of the discharge chamber 33 formed in the low pressure side cylinder head 31, and the lower side of the crankshaft 2 from the tip end side of the low pressure side pipe portion 34A. Connected to the intermediate pipe portion 34B extending rightward so as to pass through, and the suction port 22B of the suction chamber 22 formed in the cylinder head 21 on the high pressure side extending upward from the tip end side of the intermediate pipe portion 34B. Although it is formed in a substantially U-shape that opens upward from the high pressure side pipe portion 34C, the low pressure side pipe portion 34A has a discharge port 33B.
Is connected to the discharge port 33B from the lower side so as to extend downward from the discharge port 33B, so that the drain generated in the discharge chamber 33 and the drain generated in the low pressure side pipe portion 34A of the intermediate pipe 34 are connected to the intermediate pipe portion 34B side. It is designed to guide you.

Thus, even in this embodiment having the above-described structure, the same effects as those of the first embodiment can be obtained, but in particular, in this embodiment, the discharge of the cylinder head 31 on the low pressure side is achieved. The drain generated in the chamber 33 can be positively guided to the intermediate pipe portion 34B side of the intermediate pipe 34, and the discharge valve and the like in the discharge chamber 33 can be prevented from rusting due to the drain.

In the first embodiment, the case where the crankcase 1 is provided so as to incline both the low pressure side cylinder 3 and the high pressure side cylinder 9 has been described as an example. Alternatively, the low-pressure side cylinder 3 may be arranged vertically and only the high-pressure side cylinder may be inclined.

Further, in each of the above-mentioned embodiments, the case where a two-stage reciprocating air compressor including low pressure side cylinders 3 and 31 and high pressure side cylinder 21 is used as a multistage reciprocating compressor is taken as an example. However, the present invention is not limited to this, and a reciprocating air compressor having three or more stages may be used.

In each of the above-mentioned embodiments, the oil replenishment type two-stage reciprocating air compressor has been described as an example of the multi-stage reciprocating compressor, but it is applied to the oil-free reciprocating compressor. Good.

Further, in each of the above embodiments, the case where the air as the fluid is compressed by the reciprocating compressor has been described as an example, but it may be used for compressing the fluid such as the refrigerant. Moreover, you may apply to a vacuum pump.

[0038]

As described above in detail, according to the present invention, the cylinder head on the high pressure side is arranged on the cylinder on the high pressure side so that the suction port of the suction chamber opens downward, and the suction is performed. Since the intermediate pipe is connected to the suction port of the chamber so as to extend downward, the drain generated in the suction chamber of the cylinder head on the high pressure side when the operation is stopped is caused to flow out from the suction port opening downward into the intermediate pipe, By circulating downward with the drain generated in the intermediate pipe and guiding it to the lower end side of the intermediate pipe, it is possible to prevent the drain from being stored in the suction chamber and prevent rusting of each part due to the drain. The life of the reciprocating compressor can be extended. In particular, in a refueling type compressor, since it is possible to prevent the clouding phenomenon of the lubricating oil due to the mixing of drain, it is possible to maintain the lubricating effect of the lubricating oil, the rust preventive effect, etc. for a long period of time. The life can be extended.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a two-stage reciprocating air compressor showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a two-stage reciprocating air compressor showing a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view showing a conventional two-stage reciprocating air compressor.

FIG. 4 is a configuration diagram of the two-stage reciprocating air compressor shown in FIG. 3 viewed from above.

5 is a side view of the two-stage reciprocating air compressor shown in FIG.

[Explanation of symbols]

 1 Crankcase 3 Low Pressure Side Cylinder 4,21,31 Cylinder Head 5,22,32 Suction Chamber 5A, 22B, 32B Suction Port 6,23,33 Discharge Chamber 6A, 23B, 33B Discharge Port 7,13 Piston 9 High Pressure Side Cylinder 24,34 Intermediate piping

Claims (1)

[Claims] 1. A crankcase, a low-pressure side cylinder mounted on the crankcase, a high-pressure side cylinder mounted on the crankcase with an inclination, and mounted on each of the cylinders. A cylinder head defined by a suction chamber and a discharge chamber; and a piston that is reciprocally provided in each of the cylinders and that compresses the fluid sucked from the suction chamber of the cylinder head and discharges it to the discharge chamber side. In a multistage reciprocating compressor consisting of an intermediate pipe connecting the discharge chamber of the cylinder head on the low pressure side and the suction chamber of the cylinder head on the high pressure side, the cylinder head on the high pressure side is the suction port of the suction chamber. Is arranged on the cylinder on the high-pressure side so as to open downward, and the intermediate pipe is connected to the suction port of the suction chamber so as to extend downward. Reciprocating compressor.