The present invention relates to a valve plate device for a compressor, and specifically, to a compressor valve plate device which enables a suction valve to perform a smooth operation.
For example, in a piston-type compressor which has a plurality of cylinders, usually, a valve plate device is interposed between a cylinder head having a suction chamber and a discharge chamber and a cylinder block having cylinder bores. This valve plate device has a valve plate having a suction hole communicating between the suction chamber and the cylinder bore and a discharge hole communicating between the cylinder bore and the discharge chamber, a suction valve disposed on a surface of the valve plate facing the cylinder block for opening and closing the suction hole, and a discharge valve disposed on a surface of the valve plate facing the cylinder head for opening and closing the discharge hole.
This valve plate device is provided for preventing back flow of gas when a piston reciprocally inserted into a cylinder bore is in a suction stroke and a discharge stroke. More concretely, when a piston is in a suction stroke, the suction valve opens the suction hole of the valve plate and the discharge valve closes the discharge hole of the valve plate, and when the piston is in a discharge stroke, the suction valve closes the suction hole of the valve plate and the discharge valve opens the discharge hole of the valve plate, thereby preventing back flow of gas.
In case of a conventional general valve plate device, the valve plate is formed in a flat plate without irregularity. On the other hand, a lubricant oil for lubricating a compressor is contained in the gas sucked and compressed by the compressor at a mist condition. When the lubricant oil contained in this gas at a mist condition touches to the valve plate, a part thereof adheres to the valve plate in a form of oil film. The lubricant oil having adhered to the valve plate enters into a portion between the valve plate and the suction valve, and the suction valve is made difficult to be opened by a sticking force due to the surface tension, the adhesion force, etc. of the lubricant oil. As a result, in order to open the suction valve, it is necessary to add a force excessively by an amount of the sticking force due to the surface tension, the adhesion force, etc. of the lubricant oil in addition to a sticking force due to a rigidity of the suction valve itself, and in order to obtain this force, it becomes necessary to enlarge a pressure difference between the inside of the cylinder bore and the inside of the suction chamber, and whereby, the piston must perform an excessive work. Further, when the suction valve having been sticking opens, because there is a fear that the valve violently strikes a recessed portion regulating the opening degree of the valve, it may cause occurrence of noise and vibration.
Where, as for the discharge valve side, in order to prevent an excessive compression that may occur by a condition where the discharge valve becomes difficult to be opened by the lubricant oil, Patent document 1 discloses a structure wherein a gas filling concave portion is formed on a portion of the valve plate facing the discharge valve. However, this Patent document 1 does not refer as to the suction chamber side. Further, although Patent document 2 discloses a structure wherein a concave portion for introducing a suction pressure is formed on a surface of the valve plate facing the suction valve, because the suction pressure is relatively low, it is difficult to enough encourage the opening operation of the suction valve.
Patent document 1: JP-A-11-166480
Patent document 2: Japanese Utility Model Laid-Open 5-89876
Paying attention to the problems accompanying with the above-described sticking of a suction valve, although it has not yet been published, the applicant of the present invention has proposed prior to the present application a mechanism (called as a forcible valve opening mechanism) wherein by returning a part of discharge gas to the back surface side of the suction valve (a portion between the suction valve and the valve plate), the suction valve is forcibly opened utilizing the pressure due to the discharge gas (Japanese Patent Application No. 2008-168501). The forcible valve opening mechanism has been proved to be effective in reduction of sticking also in an actual device. In this actual device for proof, although a route for returning the discharge gas up to the back side of the suction valve (a gas introduction route) is formed by defining a groove on the valve plate, in this formation, because the valve plate is formed from a relatively thick plate, a load to a pressing machine increases in a mass production, and there is a fear that the cost for production may increase. Therefore, in the above-described previous proposal, although it is also proposed to form the gas introduction route on a discharge valve comprising a thin plate, it describes only a principal structure and does not propose a concrete structure, and further, does not propose a desirable structure for the formation. Therefore, problems and subject matter to be solved with the problems for actually carrying out have not been made clear, and means for solving the problems also has not been made clear.
Accordingly, paying attention to the above-described problems at the suction valve side and paying attention also to the technology previously proposed by the applicant of the present invention, an object of the present invention is to provide a structure capable of preventing or suppressing increase of consumption power and occurrence of noise and vibration which have occurred by a difficulty of opening of a suction valve due to a sticking force of lubricant oil, and even in a mass production, to provide a compressor valve plate device capable of reducing a load to a pressing machine, etc. and decreasing a cost for production, which is formed as a more concrete and desirable structure.
To achieve the above objects, a valve plate device for a compressor according to the present invention which is interposed between a cylinder head having a suction chamber and a discharge chamber and a cylinder block having a cylinder bore inserted reciprocally with a piston and which comprises a valve plate having a suction hole communicating between the suction chamber and the cylinder bore and a discharge hole communicating between the cylinder bore and the discharge chamber, a suction valve disposed on a surface of the valve plate facing the cylinder block for opening and closing the suction hole, and a discharge valve disposed on a surface of the valve plate facing the cylinder head for opening and closing the discharge hole, is characterized in that in the valve plate, at least a part of a gas filling chamber capable of introducing and filling gas with a higher pressure than a suction gas pressure in the suction chamber between the valve plate and the suction valve is constituted and a communication hole communicating with a surface at a valve closing side of the suction valve is provided, at least a part of a gas introduction route for introducing the gas with a higher pressure than a suction gas pressure in the suction chamber into the communication hole is formed on the discharge valve, and a part of the gas introduction route formed on the discharge valve is sealed by a member disposed on a surface facing the discharge valve.
In such a compressor valve plate device according to the present invention, when the suction valve is being closed, it becomes possible to introduce the gas with a higher pressure than a suction gas pressure in the suction chamber into the surface portion of the valve closing side of the suction valve through the gas introduction route and the communication hole, and the introduced gas is filled in the gas filling chamber formed between the valve plate and the suction valve so as to be able to introduce and fill the gas. Thus, by the condition where the gas with a higher pressure than a suction gas pressure in the suction chamber is introduced into a portion of the surface of the valve closing side of the suction valve being closed (a surface of the side facing the valve plate) through the communication hole and the gas is filled at the portion, when the pressure in the cylinder bore reduces in the suction stroke of the piston (expansion stroke of the gas in the cylinder bore), a pressure difference is generated between the pressure of the filled gas and the pressure in the cylinder bore, and by this pressure difference, a force is generated in a direction for pushing up the suction valve (in a direction for opening the valve). By adding this force in the direction for opening the valve, even if there is a sticking due to the lubricant oil, it becomes possible to open the suction valve quickly and smoothly, it is not necessary for the piston to perform an excessive work, and therefore, the consumption power of the compressor can be decreased. Further, by the condition where the suction valve is opened quickly and smoothly, the noise and vibration, which may have occurred by the condition where the suction valve violently strike the recess, may be decreased. Then, by the formation where at least a part of the gas introduction route for introducing the gas with a higher pressure than a suction gas pressure in the suction chamber into the communication hole is formed on the discharge valve formed from a relatively thin plate, forming the gas introduction route may be facilitated, and in case of forming it, a load to a pressing machine may be decreased, and therefore, the cost for mass production may be decreased. Further, by the structure where at least a part of the gas introduction route is formed on the discharge valve comprising a thin plate member which is easy to be formed, freedom in arrangement of the gas introduction route can be increased, and therefore, a forcible valve opening mechanism for stabilizing the operation of the suction valve can be applied to various kinds of devices. Further, by the structure where at least a part of the gas introduction route is formed on the discharge valve, even in case where the remaining portion of the gas introduction route is formed on the valve plate, the route length of the gas introduction route to be formed on the valve plate can be decreased, and it becomes to improve the durability against gas blow by of the valve plate (blow-by durability). Furthermore, by the structure where a part of the gas introduction route formed on the discharge valve is sealed by the member disposed on a surface facing the discharge valve (for example, a gasket or a retainer integrated gasket for the discharge valve interposed between the discharge valve and the cylinder head, or the valve plate), the gas with a higher pressure than a suction gas pressure in the suction chamber into the surface portion of the valve closing side of the suction valve through the gas introduction route may be introduced into the surface portion of the valve closing side of the suction valve efficiently at a condition where a desired pressure is maintained, and a quick and smooth valve opening operation of the suction valve can be ensured more securely.
In the above-described compressor valve plate device according to the present invention, a structure may be employed wherein at least a part of the gas introduction route formed on the discharge valve passes through a portion corresponding to at least a part of a partition wall between the discharge chamber and the suction chamber in the cylinder head. Namely, it is a structure wherein at least a part of the gas introduction route is provided within a positional area positioned with the partition wall of the cylinder head. Since the portion of the partition wall of the cylinder head is a portion being fixed by fastening and the like and its surface pressure is high, by the above-described structure, the sealability of the gas introduction route at that portion can be improved utilizing the surface pressure of the partition wall portion of the cylinder head, and gas leakage from the gas introduction route can be decreased.
Further, a structure may also be employed wherein at least a part of the gas introduction route formed on the discharge valve passes through a portion corresponding to at least a part of an outer circumferential wall of the cylinder head. Similarly to the structure described above, since the portion of the outer circumferential wall of the cylinder head also has a high surface pressure, by providing at least a part of the gas introduction route within a positional area positioned with this outer circumferential wall, the sealability of the gas introduction route at that portion can be improved, and gas leakage from the gas introduction route can be decreased.
Further, a structure may be employed wherein a bead is formed on at least a part of the member disposed on a surface facing the discharge valve for sealing at least a part of the gas introduction route formed on the discharge valve or a portion including the part of the gas introduction route and a circumferential portion of the communication hole. By forming such a bead, since it becomes possible to locally increase the surface pressure for sealing at the portion of the bead, the sealability of the gas introduction route surrounded by this bead can be improved, and gas leakage from the gas introduction route can be decreased.
Further, a structure may be employed wherein at least a part of a facing surface of at least one of the discharge valve and the member disposed on a surface facing the discharge valve is formed from a polymer material. If an adequate polymer material capable of adhering to the facing surface is selected, by employing such a member at least at a part of which is formed from the polymer material, the sealability of the gas introduction route can be improved, and gas leakage from the gas introduction route can be decreased.
Further, it is preferred that at least a part of the gas introduction route formed on the discharge valve is formed by punching. Because the discharge valve is formed as a thin plate as compared with the valve plate, it is possible to perform punching easily, by punching, a predetermined gas introduction route can be formed on the discharge valve by a low processing load easily at a high accuracy, and it becomes possible to decrease time for processing and cost for production.
Further, it is also possible to form at least a part of the gas introduction route formed on the discharge valve by bead processing. If the path is formed by bead processing, it becomes possible to give the bead portion both a path forming function and a seal function, and therefore, it becomes possible to easily form a gas introduction route having a good sealability by a simple structure.
Further, a structure may also be employed wherein a seal material, for a part of which a polymer material is used, is nipped between the discharge valve and the member disposed on a surface facing the discharge valve (for example, a gasket or the valve plate). By such an interposition of the seal material, the sealability of the gas introduction route formed on the discharge valve can be improved, and if the seal material is extended up to the circumferential portion of the communication hole, the sealability for the communication hole can also be improved.
Further, a structure may also be employed wherein the discharge valve and the member disposed on a surface facing the discharge valve are bonded to each other by a polymer material having an adhesive property at least at a part of a portion present therebetween. In such a structure, because both members are bonded by adhesion directly to each other by the polymer material, the sealability of a necessary portion can be improved easily and surely.
The above-described discharge valve and the valve plate may be connected to each other by an appropriate connecting means. For example, a structure may be employed wherein the discharge valve and the valve plate are connected to each other by a rivet or a bolt at least at one position or more.
In order to ensure a good sealability, it is preferred that a seal portion for at least a part of the gas introduction route formed on the discharge valve is configured at a seal width of a certain level or more, and for example, the seal width is preferably set at 0.2 mm or more.
Further, although the formation for supporting the discharge valve is not particularly limited, in order to hold it between the cylinder head and the valve plate at a predetermined form, for example, a structure may be employed wherein at least a part of a portion of the discharge valve positioned in the discharge chamber is supported by the cylinder head.
Further, it is possible to perform barrel polishing for at least a part of the gas introduction route formed on the discharge valve. Since the inner surface of the gas introduction route at this portion is processed to a smooth surface with no irregularity by barrel polishing, the resistance against gas flow in the path can be greatly reduced, and the introduced gas can be easily introduced into the communication hole at a condition where a desired pressure is kept.
Further, in the present invention, although a structure may be employed wherein the gas introduction route formed on the discharge valve extends at a constant width, a structure may also be employed wherein the width of the gas introduction route varies partially.
Further, in case where at least a part of the gas introduction route formed on the discharge valve passes through a portion corresponding to the partition wall between the discharge chamber and the suction chamber in the cylinder head, the width of the gas introduction route at that portion is preferably smaller than the width of the partition wall between the discharge chamber and the suction chamber. By employing such a path width, utilizing a high surface pressure for sealing at the portion corresponding to the partition wall, the sealability of the gas introduction route at this portion may be improved.
Further, the gas introduction route formed on the discharge valve may extend bending or curving on the way. In consideration of the sealability, etc. required for the gas introduction route, the path width and the extending formation may be decided.
In the present invention, it is possible to employ various structure as a passageway of the gas introduction route. For example, the gas introduction route may be formed in an order of valve plate-discharge valve-valve plate, and may also be formed in an order of valve plate-discharge valve.
Further, a structure may be employed wherein as a route for introducing gas which includes as far as said communication hole, it may be a structure formed by the discharge valve and the valve plate.
The above-described compressor valve plate device according to the present invention can be applied basically to any type compressor. In particular, it is suitable for application to a compressor used for an air conditioning system for a vehicle for which noise and vibration are desired to be suppressed.
In the compressor valve plate device according to the present invention, since a force in a valve opening direction can be added to the suction valve by the gas with an adequate pressure which is introduced into and filled in the gas filling chamber formed on the surface at the valve plate side of the suction valve, it is prevented that the suction valve becomes difficult to be opened by the sticking force due to lubricant oil, and it becomes possible to prevent or suppress increase of consumption power of the compressor which has been generated by the difficulty of the opening operation of the suction valve and occurrence of noise and vibration at the time of opening of the suction valve. Further, a gas route with a desirable performance can be easily formed by the structure wherein at least a part of the gas introduction route for introducing the gas with an adequate pressure is formed on the discharge valve formed from a relatively thin plate, and a structure for sealing the gas introduction route. Moreover, in the present invention, since various structures for mass production of such a valve plate device are concretely proposed, it becomes possible to decrease the load to a pressing machine, etc. and to reduce the cost for production, and actually this valve plate device can be adequately applied to various kinds of compressors.
Hereinafter, desirable embodiments of the present invention will be explained referring to figures.
In this embodiment, valve plate device 20 is constructed as shown in
In compressor valve plate device 20 thus constructed, when suction valve 26 is being closed, it becomes possible to introduce gas with a pressure higher than the pressure of suction gas in the suction chamber (in this embodiment, discharge gas) into the surface of the valve closing side of the suction valve 26 through gas introduction route 32 and communication hole 31, and the introduced gas in filled in gas filling chamber 30 including gas filling recessed portion 36 which is formed between valve plate 25 and suction valve 26. In the suction stroke of piston 3 (expansion stroke of the gas in cylinder bore 4), by reduction of the pressure in cylinder bore 4, there occurs a pressure difference between the gas filled in gas filling chamber 30 with a pressure higher than the pressure of the suction gas in the suction chamber and the pressure in cylinder bore 4, and by this pressure difference, a force in a direction for pushing up suction valve 26 (in a direction for opening the valve) is generated. Since this force in the valve opening direction is added, even if there is a sticking due to lubricant oil, it becomes possible to open suction valve 26 quickly and smoothly. Further, because by the amount thereof it is not necessary for piston 3 to perform an excessive work, the consumption power of the compressor can be decreased. Furthermore, by the quick and smooth opening operation of suction valve 26, the noise or vibration, which may have been generated by a violent striking of suction valve 26 to recess 37, can be decreased.
Since at least a part (in this embodiment, path portion 33) of gas introduction route 32 for introducing gas with a pressure higher than the suction gas pressure in the suction chamber into communication hole 31 is formed on discharge valve 27 formed from a relatively thin plate member, for example, when formed by pressing, the load to a pressing machine is decreased, and the cost for production at the time of mass production may be reduced. Further, by the condition where at least a part of gas introduction route 32 is formed on discharge valve 27 formed from a thin plate member which is easy to be formed, the freedom for arrangement of gas introduction route 32 is increased, and for example, it also becomes possible to extend it a state of bending or curving, and therefore, to various kinds of devices, the forcible valve opening mechanism for stabilizing the operation of suction valve 26 may be applied. Furthermore, by the condition where at least a part of gas introduction route 32 (path portion 33) is formed on discharge valve 27, even in case where the remaining portions of gas introduction route 32 (path portions 34, 35) are formed on valve plate 25, the length of the route of gas introduction route 32 to be formed on valve plate 25 can be greatly decreased, and it becomes possible to improve the blow-by durability of valve plate 25.
Further, by the member disposed on a surface facing discharge valve 27 (in the above-described embodiment, retainer integrated gasket 29), a part of gas introduction route 32 (path portion 33) formed on discharge valve 27 can be easily sealed, and a good sealability can be exhibited by gasket 29, and therefore, the gas with a pressure higher than the suction gas pressure in the suction chamber, which is introduced into the surface of the valve closing side of suction valve 26 through gas introduction route 32, may be introduced into the surface side of the valve closing side of suction valve 26 efficiently at a state where a desired pressure is kept. By this gas pressure, a quick and smooth valve opening operation of suction valve 26 may be ensured more securely.
Further, with respect to the sealability, for example, as shown in
The compressor valve plate device according to the present invention can be applied basically to any type compressor, and in particular, it is suitable to be applied to a compressor used for an air conditioning system for a vehicle for which noise and vibration are desired to be suppressed.
Number | Date | Country | Kind |
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2008-294409 | Nov 2008 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2009/006188 | 11/18/2009 | WO | 00 | 5/18/2011 |