JP2008088878A - Reciprocating compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating compressor always keeping discharge pressure of the compressor at a target pressure that prevents damage of a compressor structural member and satisfies a desired working pressure for a discharge gas using equipment of the compressor without increasing the number of part items and machining man-hours, and manufacturing costs caused thereby. <P>SOLUTION: This reciprocating compressor is configured such that gas sucked from a suction port opened/closed by an inlet valve into a cylinder is compressed by a piston reciprocating in the cylinder and delivered from a delivery port opened/closed by a delivery valve to the gas using equipment connected to the delivery port. The volume value of a cylinder clearance volume part at a top dead center of the piston is set such that the maximum pressure in the cylinder determined by a compression ratio calculated by a ratio of the stroke volume value of the piston to the volume value of the cylinder clearance volume satisfies the desired pressure for the gas using equipment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas connected to a discharge port from a discharge port opened and closed by a discharge valve by compressing a gas sucked into a cylinder from a suction port opened and closed by a suction valve and reciprocating in the cylinder. The present invention relates to a reciprocating compressor configured to be sent to a use destination.

In-cylinder pressure control methods for reciprocating compressors include pressure switch control (automatic operation stop control), unloader control (load / no load control), safety valve control (upper limit pressure discharge release), and combinations of these. The multiple control selection method is adopted.
In such a cylinder pressure control system, a pressure switch is required for pressure switch control, an unloader is required for unloader control, a safety valve is required for safety valve control, and the operation stability of each control device is maintained. Equipped with an air reservoir (gas reservoir).

In such a reciprocating compressor, the maximum discharge pressure Pmax of the compressor is determined by the compression ratio κ of the piston (κ = (Vh + Vc) / Vc · Vh: stroke volume, Vc: cylinder gap volume at top dead center) When the cylinder gap volume Vc is designed to be too small, the maximum discharge pressure Pmax may exceed an allowable value, which may cause excessive stress on members around the cylinder and motion members.
In order to avoid such an excessive increase in the maximum discharge pressure Pmax, a means for controlling the maximum discharge pressure Pmax to an allowable value or less by providing a discharge pressure control device is used.

In the technique of Patent Document 1 (Japanese Patent Publication No. 2004-510101) provided as one of the means for controlling the maximum discharge pressure, a cylinder cover is provided with a relief hole and a relief valve for opening and closing the relief hole, and a piston is provided. At the end of the piston compression process, the relief valve is opened by a driving projection protruding from the top of the cylinder, and a part of the gas in the cylinder is extracted outside through the relief hole, and the maximum discharge pressure is kept below the allowable value. Yes.
Special table 2004-510101 gazette

  The maximum discharge pressure Pmax of the compressor does not cause an excessive stress that causes damage to the members around the cylinder and the moving member, and is used for the equipment (gas usage destination) that uses the discharge gas of the compressor. It is necessary to satisfy the required working pressure. In the technique of Patent Document 1 (Japanese Patent Publication No. 2004-510101), the above-mentioned maximum discharge pressure control means is provided, and the maximum discharge pressure is determined under both conditions. The target pressure is controlled so that it can be provided.

  However, in the technique of Patent Document 1, a cylinder cover is provided with a relief hole, a relief valve that opens and closes the relief hole, and an opening / closing mechanism thereof, and a piston that has a drive projection formed on the top is specially manufactured. In order to control the maximum discharge pressure, special installation and processing of special members are required. For this reason, in this technique, the number of parts increases and the number of processing steps increases, leading to an increase in the manufacturing cost of the compressor.

  In view of the problems of the prior art, the present invention prevents the compressor discharge pressure from being damaged and reduces the compressor discharge pressure without increasing the number of parts, the number of processing steps, and the manufacturing cost. An object of the present invention is to provide a reciprocating compressor that can always be maintained at a target pressure that can satisfy the required working pressure of the discharge gas usage destination.

  The present invention achieves such an object, and compresses a gas sucked into a cylinder from a suction port opened and closed by a suction valve by a piston reciprocating in the cylinder, and then from the discharge port opened and closed by a discharge valve. In a reciprocating compressor configured to be sent to a gas user connected to a discharge port, a volume value of a cylinder gap volume at the bottom dead center of the piston and a cylinder gap volume at a top dead center of the piston The maximum in-cylinder pressure determined by the compression ratio calculated by the ratio with the volume value is set so as to be the required pressure of the gas user.

In this invention, specifically, the following configuration is preferable.
(1) The cylinder cover that covers the cylinder is configured as a bowl-shaped cylinder cover in which a suction chamber that communicates with the suction port and a discharge chamber that communicates with the discharge port are provided.
(2) The suction port and the suction valve are provided on one side of the upper side wall of the cylinder, the discharge port and the discharge valve are provided on the other side of the upper side wall, and the discharge port is provided on the discharge side of the cylinder. A discharge chamber communicated is provided, and the discharge valve is installed so as to open and close the discharge port and the discharge chamber.
(3) A suction port that is opened and closed by the suction valve is opened on an upper surface of the piston facing the cylinder gap volume, a suction passage that communicates with the suction port is provided in the piston, and the cylinder is provided on the upper side wall of the cylinder. A discharge port and a discharge valve are provided, a discharge chamber communicated with the discharge port is provided on the discharge side of the cylinder, and the discharge valve is installed to open and close the discharge port and the discharge chamber.
(4) A second cylinder gap volume portion communicating with the cylinder gap volume portion is formed on the side wall portion of the cylinder, and a volume adjusting piston for changing the volume of the second cylinder gap volume portion is provided.

  According to the present invention, at the time of manufacturing the compressor, the volume value of the cylinder gap volume at the top dead center of the piston is used, and the maximum gas pressure in the cylinder determined by the compression ratio is used for equipment such as equipment that uses the discharge gas of the compressor. The relief hole and the relief valve provided in the cylinder cover in the technique of Patent Document 1, the opening / closing mechanism thereof, and the piston top portion are simply set by setting the volume value so as to be the previous required pressure (required use pressure). Without requiring a mechanism for controlling the maximum discharge pressure of the compressor to the target pressure, such as a drive protrusion, the maximum discharge pressure can be constantly held at the required pressure of the gas user. .

  As a result, there is no increase in the number of parts and the number of parts processing man-hours for controlling the maximum discharge pressure of the compressor, and the maximum discharge pressure of the compressor is reduced without increasing the manufacturing cost. It is possible to always maintain the target pressure so as to prevent damage to the component member and satisfy the required working pressure of the discharge gas use destination.

  Further, regarding a normal compressor in which a cylinder cover that covers the cylinder is configured as a bowl-shaped cylinder cover in which a suction chamber that communicates with the suction port and a discharge chamber that communicates with the discharge port are provided. By simply inserting a spacer between the upper surface of the cylinder and the cylinder cover and adjusting the volume of the cylinder gap volume part, the existing compressor is used as it is, and the maximum discharge pressure of the compressor as described above is required. A control effect on the working pressure can be obtained.

In addition, a suction port and a suction valve are provided on one side of the upper side wall of the cylinder, a discharge port and a discharge valve are provided on the other side of the upper side wall, and a discharge port communicated with the discharge port on the discharge side of the cylinder. If the chamber is provided and the discharge valve is configured so as to open and close the discharge port and the discharge chamber, it is possible to secure a space for providing the suction valve on the upper side wall of the cylinder gap volume, and to discharge the cylinder. By providing a discharge chamber in communication with the discharge port on the side, the cylinder cover that covers the cylinder can be formed in a plate shape that does not include the discharge chamber or the like and that simply covers the cylinder and the discharge chamber.
Thereby, the structure of the cylinder cover is simplified, the manufacturing cost of the cylinder cover can be reduced, and a compact and compact structure in which the length of the piston in the axial direction is suppressed can be achieved.
Further, since the cylinder cover can be formed in a plate shape, it is possible to easily form cooling fins on the outer surface of the cylinder cover, thereby improving the cooling effect of the cylinder.

In addition, a suction port that is opened and closed by the suction valve is opened on an upper surface of the piston facing the cylinder gap volume, a suction passage that communicates with the suction port is provided in the piston, and the discharge port is formed in an upper portion of the side wall of the cylinder. A port and a discharge valve are provided, a discharge chamber connected to the discharge port is provided on the discharge side of the cylinder, and the discharge valve is installed to open and close the discharge port and the discharge chamber. For example, by providing a discharge chamber in communication with the discharge port on the discharge side of the cylinder and opening and closing the intake port on the upper surface of the piston facing the cylinder gap volume by the intake valve. The cylinder cover is not provided with a discharge chamber or the like, and can be formed in a plate shape that simply covers the cylinder and the discharge chamber. Structure of a cylinder cover is made easy, it is possible to reduce the manufacturing cost of the cylinder cover can be a small compact structure with reduced axial length of the piston.
Further, it is easy to form cooling fins on the outer surface of the cylinder cover, and the cooling effect of the cylinder can be improved.

In addition, since the intake port and intake valve are provided on the upper surface facing the cylinder gap volume of the piston, the intake valve is opened by the negative pressure in the cylinder when the piston descends, and the gas is sucked into the cylinder. The intake valve can be opened and closed by using the reciprocating motion of the piston, such as closing the intake valve by the pressure increase in the cylinder and compressing the gas.
Thus, intake can be performed from the lower side wall of the cylinder or the side wall of the crankcase, so that the degree of freedom in designing the intake intake port is improved.

  Further, a second cylinder gap volume portion communicating with the cylinder gap volume portion is formed on the side wall portion of the cylinder, and a volume adjustment piston that changes the volume of the second cylinder gap volume portion is provided. Then, the cylinder gap volume value can be defined by the total volume of the cylinder gap volume at the piston top dead center and the second cylinder gap volume, and the maximum discharge pressure that matches the required pressure of the gas user can be adjusted. it can.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

In FIG. 1 showing a reciprocating compressor according to a first embodiment of the present invention, a crankshaft 6 is provided inside a crankcase 1 indicated by reference numeral 1, and both end portions of the crankshaft 6 are main bearings 7. , 7 are rotatably supported by the crankcase 1. A cylinder 3 is fixed to the upper portion of the crankcase 1 by a plurality of bolts (not shown).
A piston 5 is fitted to the inner surface of the cylinder 3 so as to be reciprocally slidable. The piston 5 is connected to a small end portion of a connecting rod 8 via a piston pin 5a. The large end portion 8 is rotatably connected to the crankshaft 6 via a bearing. A crankcase cover 2 is fixed to one side of the crankcase 1 in the axial direction by a plurality of bolts 2a.

A valve case 4a is disposed above the cylinder 3 via a spacer 40, and a cylinder cover 4 is disposed above the valve case 4a via a gasket (not shown). The cylinder cover 4 and the valve case 4a are A plurality of bolts (not shown) are fastened to the upper surface of the cylinder 3 together.
The cylinder cover 4 is formed in a bowl shape, and a suction chamber 130 that communicates with the suction port 10 and a discharge chamber 15 that communicates with the discharge port 13 are defined by partition walls 130 therein. The intake chamber 130 has an air inlet 12 for opening air, and the discharge chamber 15 has an outlet 16 for discharging compressed air.
The suction port 10 and the discharge port 13 are opened in the valve case 4 a, and the suction port 10 is opened and closed by the suction valve 11, and the discharge port 13 is opened and closed by the discharge valve 14.

In the reciprocating compressor configured as described above, in the present invention, the upper surface of the piston 5, the inner surface of the cylinder 3, and the cylinder cover 4 side when the piston 5 is at the bottom dead center position indicated by B in FIG. The volume value of the cylinder gap volume 9 divided by the lower surface of the valve case 4a side, the upper surface of the piston 5 when the piston 5 is at the top dead center position indicated by A in FIG. The maximum pressure in the cylinder determined by the compression ratio calculated by the ratio between the inner surface and the cylinder gap volume 9 defined by the cylinder cover 4 side (valve case 4a side) is compressed air that has passed through the discharge chamber 15. The length C of the cylinder gap volume 9 is set at the time of manufacturing the compressor so that the required pressure of the user is used.
That is, the volume value of the cylinder gap volume 9 is set to the thickness of the spacer 40 so that the pressure in the cylinder gap volume 9 when the piston 5 reaches top dead center A becomes the required pressure of the user. Adjust the height. The length S indicates the stroke of the piston 5.

During operation of the reciprocating compressor having the above configuration, the crankshaft 6 is rotationally driven by a drive source such as a motor, and the rotational motion of the crankshaft 6 is converted into the reciprocating motion of the piston 5 via the connecting rod 8. .
When the piston 5 is lowered from the top dead center A to the bottom dead center B, the suction valve 11 is opened and air is introduced into the cylinder 3, and the piston 5 rises from the bottom dead center B to the top dead center A. Accordingly, when the air in the cylinder 3 is compressed and the discharge valve 14 is opened, the pulsation is eased in the discharge chamber 15, and then the compressed air is supplied to the place where the air is used through the discharge port 16.
In the figure, arrows indicate the flow of air (the same applies to FIGS. 2 to 4).

  During such operation, when the compressor is manufactured, the volume value of the cylinder gap volume 9 at the top dead center A of the piston 5 is the maximum pressure in the cylinder determined by the compression ratio, etc. Therefore, the maximum pressure in the cylinder at the top dead center A of the piston 5 is the required pressure (required use pressure) of the gas use destination. ) And the maximum pressure in the cylinder does not rise abnormally.

As described above, according to the first embodiment, when the compressor is manufactured, the maximum value in the cylinder determined by the compression ratio is used to determine the volume value of the cylinder gap volume portion 9 at the top dead center A of the piston 5. The cylinder cover in the technique of Patent Document 1 is provided only by assembling the compressor by setting the volume value so as to be the required pressure (required use pressure) of the gas use destination of the equipment using the discharge gas of Without requiring a mechanism for controlling the maximum discharge pressure of the compressor to the target pressure, such as a relief hole, a relief valve, its opening / closing mechanism, and a drive projection on the top of the piston, the maximum discharge pressure is reduced to the gas. It can always be kept at the pressure required by the user.
As a result, there is no increase in the number of parts and the number of parts processing man-hours for controlling the maximum discharge pressure of the compressor, and the maximum discharge pressure of the compressor is reduced without increasing the manufacturing cost. It is possible to always maintain the target pressure so as to prevent damage to the component member and satisfy the required working pressure of the discharge gas use destination.

  Further, the cylinder cover 4 that covers the cylinder 3 is configured as a bowl-shaped cylinder cover in which a suction chamber 130 that communicates with the suction port 10 and a discharge chamber 15 that communicates with the discharge port 13 are provided. For a normal compressor, the spacer 40 is inserted between the upper surface of the cylinder 3 and the cylinder cover 4 to adjust the volume of the cylinder gap volume portion 9, and the existing compressor is used as it is. Such a control effect of the maximum discharge pressure of the compressor to the required working pressure can be obtained.

FIG. 2 is an upper partial sectional view taken along the cylinder center line 100 of the reciprocating compressor according to the second embodiment of the present invention.
In the second embodiment, the suction port 20 and the suction valve 11 for opening and closing the suction port 20 are provided in the horizontal direction on one side of the upper side wall of the cylinder 3, and the other side (suction port) of the upper side wall. The discharge port 23 and the discharge valve 14 for opening and closing the discharge port 23 are provided on the opposite side of the discharge port 23.
Further, a discharge chamber 24 communicating with the discharge port 23 is provided on the discharge side side portion of the cylinder 4, and the discharge valve 14 is installed so as to open and close between the discharge port 23 and the discharge chamber 24. .
The upper opening of the cylinder 3 and the upper opening of the discharge chamber 24 are covered with a plate-like cylinder cover 21.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

According to the second embodiment, since the height of the cylinder gap volume portion 9 can be made large, a space for providing the suction valve 11 can be secured in the upper portion of the side wall, and the discharge port 23 communicates with the discharge side portion of the cylinder 3. By providing the discharge chamber 24, the cylinder cover 21 that covers the cylinder 3 can be formed in a plate shape that simply covers the cylinder 3 and the discharge chamber 24 without providing the discharge chamber or the like.
A space for providing a suction valve in the upper part of the side wall of the cylinder gap volume part can be secured, and a cylinder cover that covers the cylinder by providing a discharge chamber connected to the discharge port on the discharge side of the cylinder is provided with a discharge chamber and the like. Instead, it can be formed in a plate shape that simply covers the cylinder and the discharge chamber.
As a result, the structure of the cylinder cover 21 is simplified, the manufacturing cost of the cylinder cover 21 can be reduced, and a compact and compact structure in which the length of the piston in the axial direction can be suppressed.
Further, since the cylinder cover 21 can be formed in a plate shape, cooling fins (not shown) can be easily formed on the outer surface of the cylinder cover 21, and the cooling effect of the cylinder 3 can be improved.

FIG. 3 is a diagram corresponding to FIG. 2 showing a third embodiment of the present invention.
In the third embodiment, the discharge side has the same structure as the second embodiment, and is provided with a discharge port 23 and a discharge valve 14 that opens and closes the discharge port 23 on the side wall. The piston suction port 25 is opened on the upper surface of the piston 5 facing the cylinder gap volume 9, and the piston suction port 25 is opened and closed by the suction valve 11.
In the third embodiment, an air suction port (not shown) is provided in the lower side wall of the cylinder 3 or the side wall of the crankcase 1, and the suction valve 11 is opened by the negative pressure in the cylinder 3 when the piston 5 is lowered. Air is sucked into the cylinder 3 from the suction port 25 through the suction passage in the piston, and when the piston 5 is lifted, the suction valve 11 is closed by the pressure increase in the cylinder 3 to compress the gas.
Similarly to the second embodiment, the upper opening of the cylinder 3 and the upper opening of the discharge chamber 24 are covered with a plate-like cylinder cover 21.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

According to the third embodiment, the discharge chamber 24 communicated with the discharge port 23 is provided on the discharge side portion of the cylinder 4, and the piston suction port 25 is formed on the upper surface of the piston 5 facing the cylinder gap volume portion 9. As in the second embodiment, the cylinder cover 21 can be formed in a plate shape that simply covers the cylinder 3 and the discharge chamber 24, and the cylinder cover 21 is opened and closed by the intake valve 11. The structure of 21 can be simplified, the manufacturing cost of the cylinder cover 21 can be reduced, and a small and compact structure in which the length of the piston in the axial direction can be suppressed.
Further, it is possible to easily form cooling fins on the outer surface of the cylinder cover 21 and improve the cooling effect of the cylinder.
Further, since the piston suction port 25 and the suction valve 11 are provided on the upper surface of the piston 5 facing the cylinder gap volume 9, when the piston 5 is lowered, the suction valve 11 is opened by the negative pressure in the cylinder 3 to enter the cylinder 3. The suction valve 11 is opened and closed by using the reciprocating motion of the piston 5 such that air is sucked and the suction valve 11 is closed and the gas is compressed by the pressure increase in the cylinder 3 when the piston 5 is lifted. Can do.
As a result, intake can be performed from the lower side wall of the cylinder 3 or the side wall of the crankcase 1, so that the degree of freedom in designing the intake intake port is improved.

FIG. 4 is a diagram corresponding to FIG. 2 showing a fourth embodiment of the present invention.
In the fourth embodiment, a second cylinder gap volume 30 communicating with the cylinder gap volume 9 is formed on the discharge side of the cylinder 3, and the second cylinder gap volume 30 is formed in the second cylinder gap volume 30. A volume adjustment piston 31 is fitted so as to be able to reciprocate, and a return spring 32 is interposed between the lower surface of the volume adjustment piston 31 and the bottom surface of the second cylinder gap volume portion 30.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

According to the fourth embodiment, the cylinder gap volume value can be defined by the total volume of the cylinder gap volume portion 9 and the second cylinder gap volume portion 30 at the piston top dead center, and is adapted to the required pressure of the gas user. The maximum discharge pressure can be adjusted.
In addition, since the volume of the second cylinder gap volume portion 30 communicated with the cylinder gap volume portion 9 varies depending on the balance between the cylinder pressure and the force of the spring 32, the spring force is adjusted so that the piston 5 The total volume of the cylinder gap volume 9 and the second cylinder gap volume 30 at the top dead center A can be set, and the maximum discharge pressure that matches the required pressure of the gas user can be automatically held. .

  In the above embodiment, the reciprocating compressor that is delivered to the gas user has been described. However, the user is not particularly limited, and the reciprocating booster compressor has the same mechanism as the reciprocating compressor of the present invention. Of course, it may be used.

  According to the present invention, the discharge pressure of the compressor can be prevented from being damaged and the discharge gas used by the compressor can be used without increasing the number of parts, increasing the number of processing steps, and increasing the manufacturing cost. It is possible to provide a reciprocating compressor that can always be maintained at a target pressure that can satisfy the required working pressure.

It is sectional drawing along the cylinder centerline of the reciprocating compressor which concerns on 1st Example of this invention. FIG. 6 is an upper partial cross-sectional view along a cylinder center line of a reciprocating compressor according to a second embodiment of the present invention. FIG. 6 is a view corresponding to FIG. 2 showing a third embodiment of the present invention. FIG. 9 is a view corresponding to FIG. 2 showing a fourth embodiment of the present invention.

Explanation of symbols

1 Crankcase 2 Crankcase cover 3 Cylinder 4, 21 Cylinder cover 4a Valve case 5 Piston 6 Crankshaft 10, 20 Suction port 11 Suction valve 13, 23 Discharge port 14 Discharge valve 15, 24 Discharge chamber 25 Piston suction port 30 2nd Cylinder gap volume 31 Volume adjustment piston 40 Spacer 130 Suction chamber

Claims (5)

  Gas sucked into a cylinder from a suction port that is opened and closed by a suction valve is compressed by a piston that reciprocates in the cylinder, and sent from a discharge port that is opened and closed by a discharge valve to a gas usage destination connected to the discharge port. In the reciprocating compressor configured to perform the compression, the compression is calculated by a ratio between the volume value of the cylinder gap volume at the bottom dead center of the piston and the volume value of the cylinder gap volume at the top dead center of the piston. A reciprocating compressor characterized in that a maximum pressure in a cylinder determined by a ratio is set to be a required pressure of the gas user.   2. The cylinder cover that covers the cylinder is configured as a bowl-shaped cylinder cover in which a suction chamber that communicates with the suction port and a discharge chamber that communicates with the discharge port are provided side by side. The reciprocating compressor described.   The suction port and the suction valve are provided on one side of the upper portion of the side wall of the cylinder, the discharge port and the discharge valve are provided on the other side of the upper portion of the side wall, and communicated with the discharge port on the discharge side of the cylinder. The reciprocating compressor according to claim 1, wherein a discharge chamber is provided, and the discharge valve is installed so as to open and close the discharge port and the discharge chamber.   A suction port that is opened and closed by the suction valve is opened on an upper surface of the piston facing the cylinder gap volume, a suction passage communicating with the suction port is provided in the piston, and the discharge port and the upper side wall of the cylinder are provided. A discharge valve is provided, a discharge chamber connected to the discharge port is provided on a discharge side side of the cylinder, and the discharge valve is installed to open and close the discharge port and the discharge chamber. Item 2. The reciprocating compressor according to Item 1.   A second cylinder gap volume portion communicating with the cylinder gap volume portion is formed on a side wall portion of the cylinder, and a volume adjustment piston for changing the volume of the second cylinder gap volume portion is provided. The reciprocating compressor according to claim 1.

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