JP3602700B2 - Compressor injection device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection device for a compressor in which a fluid to be compressed is injected into various compressors so as to supercharge the fluid to be compressed, and more particularly to an injection device for a compressor mainly used for refrigeration and air conditioning for business and home use. It is about.
[0002]
[Prior art]
Electric compressors for refrigeration and air conditioning include those having a reciprocating compressor, a rotary compressor, and a scroll compressor. Currently, it is growing by making use of its features in terms of cost and performance. Among them, scroll compressors have been put to practical use taking advantage of the features of high efficiency, low noise, and low vibration.
[0003]
Japanese Patent Application Laid-Open No. 08-144971 discloses that a refrigerant gas at an intermediate pressure separated by a gas-liquid separator is injected into a compression chamber formed between a fixed scroll and an orbiting scroll by a scroll compressor via a check valve. Further, the disclosure discloses that a stable and efficient gas injection is realized by utilizing a gentle compression characteristic of a scroll compressor.
[0004]
[Problems to be solved by the invention]
However, in the conventional scroll compressor, the check valve for gas injection is provided on an outer peripheral surface of a head plate of a fixed scroll or an injection pipe connected to a rear housing provided so as to cover a refrigerant discharge space from the head plate. Due to the structure provided in the middle, the path from the check valve to the compression chamber is complicated and long, and the injection device is complicated and large, and it is difficult to manufacture and the cost is high. In addition, a dead volume formed by a complicated and long injection path increases the amount of lubricating oil that penetrates and becomes difficult to remove even by gas injection, so that lubrication becomes unstable and performance becomes unstable.
[0005]
In addition, since the compression in the compression chamber extends to the dead volume up to the check valve position in the injection path, if the dead volume is long and large, the compression efficiency is affected, and from high-load operation, which is a high-speed operation such as heating. When gas injection is stopped to diversify the operation, such as switching to low-load operation, which is a low-speed operation such as cooling operation, the refrigerant or lubricating oil in this dead volume passes through the compression chamber in the compression process to increase the pressure. After being closed, the compressor expands again when it is connected to the next compression chamber where the closing is started. Therefore, as the dead volume increases, the performance and efficiency of the compressor are likely to decrease.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a compressor injection device which has a simple structure, a small device and a small dead volume, is inexpensive, and can prevent problems due to re-expansion of a fluid to be compressed and lubricating oil and a large amount of lubricating oil entering. Is to do.
[0007]
[Means for Solving the Problems]
According to the present invention, an inlet from an injection pipe connected to an outer surface of a fixing member forming a compression chamber, and an injection port for guiding an injection fluid from the inlet to the compression chamber in a substantially wall thickness direction. A check valve chamber is formed, and a free valve is provided in the check valve chamber to slide between an inlet surface where the introduction port opens and an outlet surface where the injection port opens. A portion from the inlet surface side of the check valve chamber to the opening of the injection port of the outlet surface between the sliding contact surface with the inner periphery of the stop valve chamber and the opposing surface where the free valve abuts on the outlet surface. A fluid passage is formed between the opposed surface where the free valve and the inlet surface are in contact with each other, and is not communicated with the opening of the inlet.
[0010]
In such a configuration, the inlet surface side and the outlet surface side of the check valve chamber are partially formed by the fluid passage provided between the free valve and the sliding contact surface between the check valve chamber that partition between them. When the injection fluid flows into the check valve chamber through the inlet at the time of injection, the dynamic pressure acts on the free valve and presses the free valve against the outlet surface, but between the facing surface and the outlet surface. Since the provided fluid passage communicates with the fluid passage and the injection port opened to the outlet surface, the injection fluid can be guided to the compression chamber with a predetermined passage resistance through the injection port, and the injection can be performed as set. Achieved. When injection is not performed, the fluid sucked into and compressed by the compression chamber also reaches the check valve chamber through the injection port, and the dynamic pressure presses the free valve against the inlet face, so that the two opposing faces are not in contact with each other. The fluid passage and the inlet from the injection pipe that opens at the inlet face contact each other, preventing the fluid to be compressed from escaping to the injection pipe side beyond the check valve, thereby achieving the compression. You can do so.
[0011]
In this case, when the check valve chamber and the free valve have a circular cross section and the ratio L / D of the diameter D and the thickness L of the free valve is 0.3 or more, the injection of the free valve is performed. This makes it easier to improve the responsiveness of opening and closing when not performed.
[0012]
In particular, the injection device is a component count less simple and compact, and inexpensive and easy fabrication.
[0013]
In addition, since the dead volume formed by the injection path from the check valve to the compression chamber also becomes smaller, the amount of refrigerant and lubricating oil that enters there is reduced. When the gas injection performed during high-load operation such as during cooling is not performed during low-load operation such as during cooling, the influence of the refrigerant or lubricating oil in the dead volume, even if re-expanded, may be reduced. It is possible to improve the efficiency and performance of the compressor at low load operation with less. Further, since the amount of the lubricating oil entering the dead volume is small even if it enters the dead volume, it is possible to reduce a decrease in lubricity of the sliding portion of the compression mechanism and prevent a decrease in performance.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
It will be described below with reference to FIGS. 1-6 with its reference examples for some embodiments of the present invention.
[0015]
( Reference example )
This reference example is an example of a case where a horizontally mounted scroll compressor for refrigeration and air conditioning is used, and FIG. 1 shows a configuration of a main part.
[0016]
To explain this, a scroll-type compression mechanism 2 is provided at one end, an electric motor 3 for driving the compression mechanism 2 is provided at an intermediate part, and an oil reservoir at a lower portion of the closed vessel 1 is provided at the other end. An oil pump 6 for sending out the oil 4 in the lubrication target 5 to the lubrication target portion is provided.
[0017]
The compression mechanism 2 is configured such that the blades 11a rising from the head plate 11d of the fixed scroll 11 and the rising blades 12a from the head plate 12d of the orbiting scroll 12 are engaged with each other in the same manner as in the related art, so that the orbiting scroll 12 moves in a circular orbit without rotating. The pair of compression chambers 13 formed between the two are provided on the end plate 11d of the fixed scroll 11 from the outer peripheral side communicating with the suction port 14 provided in the end plate 11d of the fixed scroll 11 shown in FIG. While being moved to the center side communicating with the discharge port 15, the sealed volume is reduced and compression is performed to discharge.
[0018]
The support and drive and the guide structure of the fluid to be sucked, compressed and discharged in the closed vessel 1 may be configured in any manner. Further, the oil pump 6 may be of any type. In the present reference example , the compression mechanism 2 is integrated with a main bearing member 9 fixed to one end side by bolting a fixed scroll 11 to the main bearing member 9. The scroll 12 is sandwiched. The electric motor 3 includes an annular stator 3a fixed to the closed container 1 by welding or the like, and a rotor 3b disposed inside the stator 3a. The crank for orbitally driving the orbiting scroll 12 of the compression mechanism 2 on the rotor 3b. The shaft 16 is fixed.
[0019]
The crankshaft 16 is supported by an auxiliary bearing member (not shown) fixed to the closed container 1 by welding or the like at the other end of the closed container 1, and a main shaft 18 on the opposite side is supported by the main bearing member 9. The auxiliary bearing member and the main bearing member 9 have a slide bearing 21 and the like for the bearing. The main shaft 18 is fitted with a revolving shaft 12b projecting at an eccentric position on the back surface of the end plate 12d of the revolving scroll 12 via an eccentric bearing 23 held so as to be able to reciprocate on the diameter line of the main shaft 18, and when the main shaft 18 is rotated, the main shaft 18 is rotated. The cooperation of the Oldham ring 28 provided between the bearing member 9 and the orbiting scroll 12 causes the orbiting scroll 12 to orbit so as to make a circular orbital motion without rotating with respect to the fixed scroll. However, the above bearing structure can be variously changed.
[0020]
Since the present reference example is a scroll compressor for refrigeration and air conditioning, the fluid sucked, compressed and discharged by the compression mechanism 2 is a refrigerant, especially when a chlorine-free refrigerant such as a fluorocarbon hydrogen-based refrigerant is used. The oil 4 is compatible with the oil, and even if the refrigerant does not have chlorine and lubricity cannot be expected, the oil 4 is compatible with the oil 4 and is transported by the refrigerant to the mechanical sliding portions of each part in the closed container 1. This improves lubricity.
[0021]
A gas suction pipe 32 is connected to the suction port 14, and a gas discharge pipe (not shown) on the side opposite to the gas suction pipe 32 is connected to the discharge port 15 through a refrigerant passage 33 on the oil reservoir 5 in the sealed container 1. It is connected.
[0022]
The oil pump 6 is driven by the crankshaft 16 together with the compression mechanism 2, sends out the oil 4 in the oil reservoir 5 to an oil passage 35 formed vertically through the crankshaft 16, and first supplies the oil 4 to the eccentric bearing 23. A part of the oil 4 after being supplied to the eccentric bearing 23 is supplied to the sliding bearing 22 and the compression mechanism 2 through gaps and a predetermined passage in each part, and the rest is returned to the lower oil reservoir 5. .
[0023]
Further, the discharge port 15 is provided with a check valve 42 for preventing the orbiting scroll 12 from rotating backward when the compression mechanism 2 is stopped, and a check valve stopper 43 for restricting the movement of the orbiting scroll 12.
[0024]
Between the gas discharge pipe 34 and the gas suction pipe, equipment for a refrigerating mechanism such as a condenser (not shown), an expansion valve, the gas-liquid separator 46 (not shown), a capillary tube (not shown), and an evaporator are sequentially connected. In addition, a heat pump type refrigeration cycle including the compression mechanism 2 in the closed vessel 1 is connected in a ring shape as a whole, so that low-load cooling and high-load heating can be performed. It has a structure.
[0025]
The end plate 11d of the fixed scroll 11 is provided with an injection port 51 for performing gas injection into the pair of compression chambers 13 as shown in FIGS. An injection pipe 52 is connected to the injection port 51 via a check valve 54, and a gas refrigerant supply pipe 53 from the gas-liquid separator 46 is connected to the injection pipe 52. As a result, the gas refrigerant in the gaseous phase separated into gas and liquid by the gas-liquid separator 46 is injected into the compression chamber 13 through the refrigerant supply pipe 53, the injection pipe 52, and the injection port 51, and the reverse flow of the refrigerant once injected is reversed. It is blocked by the stop valve 54. Since such gas injection increases the efficiency of the compressor in the compression mechanism 2, the heating capacity is improved accordingly.
[0026]
In accordance with the diversification of the operation of the refrigeration system, the gas injection may be performed in a timely manner in accordance with the operation state of the refrigeration system. A one-way solenoid valve 56 is provided, and the opening and closing of the refrigeration system is controlled as needed along with the operation of the refrigeration system. This control can be performed by a microcomputer together with, for example, the operation control of the refrigeration apparatus, but is not particularly limited thereto. In addition, in order to diversify the operation, in the present embodiment, in addition to the heat pump type that can also be used for cooling and heating, the electric motor 3 is controlled, for example, by an inverter so that the orbiting scroll 12 can be orbitally driven at a variable speed. It is.
[0027]
In particular, in the present reference example , the outer surface of the fixed scroll 11 which is a fixed member forming the compression chamber 13, as a preferable example , penetrates substantially from the back side of the end plate 11 d to the compression chamber 13 in the wall thickness direction. An injection port 51 is provided, and a block 82 to which an injection pipe 52 is connected is applied to a back surface as an outer surface corresponding to the injection port 51 of the fixed scroll 11 as a fixed member. As one example shown in FIG. 2A, a check valve chamber 57 is formed by cutting a part of the end plate 11d. In some cases, the side of the block 82 may be formed, or both sides may be formed. However, drilling on only one side simplifies the processing, and if one side is provided on the side of the fixed member, which is the fixed scroll 11, it is provided without bulk using the normal volume.
[0028]
The valve seat 54b having a reed valve 54a shown one example inlet 85 into the check valve chamber 57 in FIG. 2 for opening and closing from the inside (b) from the injection pipe 52 of the block 82 1 and 2 are sandwiched between a block 82 and a rear surface, which is the outer surface of the fixed scroll 11, and fastened by bolts 81 as shown in FIG. The check valve chamber 57 is closed in a sealed state. If necessary for this sealing, a sealing material may be interposed between the end plate 11d and the valve seat 54b and between the block 82 and the valve seat 54a. The injection pipe 52 is connected to the injection nozzle 87 for the block 82 and indirectly connected to the block 82. However, the invention is not limited to this. For example, a resin bush for increasing the heat resistance may be directly connected to the block 82. It can also be press-fitted for connection.
[0029]
Further, a part of the check valve chamber 57, a part of the side of the end plate 11d facing the tip end part 54a1 for closing the introduction port 85 of the reed valve 54a, is provided with a valve stopper for restricting the maximum opening position of the reed valve 54a. 88 is, for example, integrally formed. When the end plate 11d is made of aluminum or the like having low abrasion resistance, it is formed by a separate member made of an iron-based material having high abrasion resistance and provided by an appropriate method such as adhesion, brazing, or screwing. Alternatively, it may be possible to deal with maintenance-free operation such as when the compression mechanism 2 is housed in the closed container 1.
[0030]
In such an injection device, when the injection is performed, the reed valve 54a is pushed and opened by the injection pressure so that the injection is achieved, and when the injection is not performed, the reed valve 54a closes by its own restoring force or is compressed by this. The fluid pressure due to the compression in the chamber 13 is applied to increase the closing force, and the compressed fluid in the compression chamber 13 is prevented from escaping beyond the check valve to the side of the injection pipe 52 to exhibit a check valve function. Compression can be achieved.
[0031]
In addition, the injection device of the present embodiment only needs to provide the valve seat 54b between the fixed scroll 11, which is an example of the fixed member forming the compression chamber 13, and the block 82 applied to the fixed scroll 11, and the fixed scroll 11 At 11, the reed valve 54 a of the valve seat 54 b opens and closes an inlet 85 from the injection pipe 52 opened to the check valve chamber 57, and the fluid flowing from the inlet 85 when the inlet 85 is opened is compressed. The injection port 51 communicating with the chamber 13 is provided with a space for flowing from the opening, and a valve stopper 88 serving as a contact with the reed valve 54a only needs to be partially provided. It is easy and cheap.
[0032]
In addition, since the dead volume formed by the injection path from the check valve 54 to the compression chamber 13 is also reduced, the amount of the refrigerant and the lubricating oil that has entered there is reduced, so that the operation of the refrigeration compressor can be diversified. When gas injection performed during high-load operation such as during heating is not performed during low-load operation during cooling or the like, even if the refrigerant or lubricating oil in the dead volume may re-expand, It is possible to reduce the influence and improve the efficiency and performance of the compressor at low load operation. Further, since the amount of the lubricating oil entering the dead volume is small even if it enters the dead volume, it is possible to reduce a decrease in lubricity of the sliding portion of the compression mechanism 2 and prevent a decrease in performance.
[0033]
The valve seat 54b is made of a spring steel plate, and the reed valve 54a formed by punching is simple in structure and manufacture, and can be satisfied in terms of durability. However, the present invention is not limited to this, and another member having elastic restoring force can be used instead.
[0034]
( Embodiment )
In the present embodiment , as shown in FIG. 3, the basic structure is the same as that of the reference example shown in FIG. 1, and the same members are denoted by the same reference numerals and overlapping description will be omitted.
[0035]
As shown in FIG. 3, an inlet 85 from the injection pipe 52 connected to the back of the fixed scroll forming the compression chamber 13, and an injection gas from the inlet 85 is supplied to the compression chamber 13 substantially in the direction of the wall thickness. A non-return valve chamber 57 is formed between the fuel injection port 51 and the injection port 51 that guides the fuel injection port 51, and between the inlet face 57a where the introduction port 85 opens in the non-return valve chamber 57 and the outlet face 57b where the injection port 51 opens. Is provided with a free valve 54c that slides. The degree of fitting between the free valve 54c and the check valve chamber 56 depends on the dynamic pressure of the gas refrigerant due to the injection from the injection pipe 52 by the free valve 54c and the dynamic pressure of the refrigerant due to the compression in the compression chamber 13 and the rattling and twisting. It is good to have a smooth fit without any gap.
[0036]
Also, as shown in FIGS. 3 and 4A and 4B, between the sliding contact surface between the outer periphery of the free valve 54c and the inner periphery of the check valve chamber 57, and between the free valve 54c and the outlet surface 57b. A part of the check valve chamber 57 from the inlet face 57a side to the opening of the injection port 51 of the outlet face 57b, and the free valve 54c and the inlet face 57a abut against each other. A fluid passage 92 that is not communicated with the opening of the introduction port 85 is formed between the surfaces.
[0037]
3, in the form of one embodiment shown in (a) (b) of FIG. 4, the check valve chamber 57 and the free valve 54c is a circular cross section, of the free valve 54c periphery of the check valve chamber 57 The fluid passage 92 between the sliding contact surface with the inner periphery is formed by the cutout surfaces 54c1 provided on both sides of the side peripheral surface of the free valve 54c, and between the opposed surface where the free valve 54c and the inlet surface 57a abut. The fluid passage 92 is formed by a groove 54c2 formed on the end face of the free valve 54c. However, the present invention is not limited to this, and the notch surface 54c1 and the groove 54c2 may be provided at only one location in the circumferential direction, that is, only one half in the illustrated case, or at least three locations. Is also good. In addition, partial recesses such as the cutout surface 54c1 and the groove 54c2 for forming the fluid passage 92 may be provided on the check valve chamber 57 side, or may be provided on both the free valve 54c and the check valve chamber 57. You may share and provide. Check valve function with a predetermined Injection down flow amount need be guaranteed.
[0038]
In this case, the inlet face 57a and the outlet face 57b of the check valve chamber 57 have a fluid passage provided between the free valve 54c and the check surface of the check valve chamber 57, which partition between them. Although the fluid is only partially communicated by 92, the dynamic pressure when the injection refrigerant flows into the check valve chamber 57 through the inlet 85 at the time of injection acts on the free valve 54c to press the free valve 54c against the outlet surface 57b. Since the fluid passage 92 provided between the surface facing the outlet surface 57b communicates with the fluid passage 92 and the injection port 51 opened to the outlet surface 57b, the injection refrigerant from the injection pipe 52 is prevented from flowing. It can be guided to the compression chamber 13 with a predetermined passage resistance through the injection port 51, and the injection can be performed. It is achieved in constant street.
[0039]
In addition, when the injection is not performed, the refrigerant sucked into the compression chamber 13 and compressed also reaches the inside of the check valve chamber 57 through the injection port 51, and its dynamic pressure presses the free valve 54c to the inlet face 57a this time. The two opposing surfaces contact each other so that the fluid passage 92 does not communicate with the introduction port 85 from the injection pipe 52 opened to the inlet surface 57a, and the refrigerant to be compressed passes through the check valve 54 and is injected into the injection pipe. It can be prevented from escaping to the side 52 so that the compression is achieved.
[0040]
Another embodiment shown in (a) (b) of FIG. 5, instead of the notch surface 54c1 of the embodiment, which has a groove 54c3 mutually communicates with the groove 54 c 2, and the embodiment Exhibits a similar check valve function.
[0041]
Injection device of embodiment, with less simple and small number of components, that Do and inexpensive easy to manufacture.
[0042]
In the experiment of the present inventors, as shown in FIG. 5C, when the ratio L / D of the diameter D to the thickness L of the free valve 54c is 0.3 or more, the free valve 54c is It is easy to improve the responsiveness of the opening and closing operation when performing injection and when not performing injection. Specifically, the degree of freedom in setting the cross-sectional area of the fluid passage 92 and the clearance between the free valve 54c and the check valve chamber 57 is increased, and the design and manufacture are facilitated.
[0043]
According to one embodiment, the diameter of the check valve chamber 57 is 6 mm, the diameter D of the free valve 54c is 5.8 mm, the thickness L of the free valve is 3 mm, and the outer diameter of the free valve 54c of the groove 54c2 and the groove 54c3. Was suitable with a maximum depth and a cross-sectional radius of 2 mm. In addition, when the free valve 54c is formed of a material such as polyimide, polyimide containing graphite, and PEEK, the required opening / closing performance and the life corresponding to maintenance-free can be satisfied.
[0044]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, while ensuring the required non-return valve function when injection is performed and when it is not performed, an injection device becomes simple, small in number of parts, inexpensive, easy to manufacture.
[0045]
In addition, since the dead volume formed by the injection path from the check valve to the compression chamber also becomes smaller, the amount of refrigerant and lubricating oil that enters there is reduced. When the gas injection performed during high-load operation such as during cooling is not performed during low-load operation such as during cooling, the influence of the refrigerant or lubricating oil in the dead volume, even if re-expanded, may be reduced. It is possible to improve the efficiency and performance of the compressor at low load operation with less. Further, since the amount of lubricating oil entering the dead volume is small even if it enters the dead volume, it is possible to reduce a decrease in lubricity of the sliding portion of the compression mechanism and prevent a decrease in performance.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a main part of a scroll compressor showing a reference example of the present invention.
FIGS. 2A and 2B show an injection device of the compressor shown in FIG. 1, wherein FIG. 2A is a sectional view and FIG. 2B shows a valve seat having a reed valve.
FIG. 3 is a longitudinal sectional view of a main part of the scroll compressor according to the embodiment of the present invention.
4A and 4B show a free valve employed in a check valve as one embodiment provided in an injection device portion of the compressor of FIG. 3, wherein FIG. 4A is a plan view and FIG. It is a perspective view.
5A and 5B show a free valve employed in a check valve as another embodiment provided in the injection device of FIG. 3, wherein FIG. 5A is a plan view, FIG. 5B is a perspective view, and FIG. FIG. 3 is a cross-sectional view in a use state.
[Explanation of symbols]
Second compression mechanism 3 motor 11 fixed scroll 11d panel 13 the compression chamber 14 suction port 15 discharge port 51 injection port 52 injection pipe 53 coolant supply pipe 54 check valve 54c free valve 54c1 notched surface 54c2,3 groove 57 check valve chamber 57a inlet surface 57b exit surface 82 block 85 introduces port 92 fluid passageway

Claims (2)

The closed volume is reduced by the displacement of the compression chamber from the suction position to the discharge position, and the fluid sucked at the suction position is compressed and discharged to the outside at the discharge position. In the injection device of the compressor to be injected,
A check valve is provided between an inlet from the injection pipe connected to the outer surface of the fixed member forming the compression chamber and an injection port for guiding the injection fluid from the inlet to the compression chamber in a substantially wall thickness direction. A free valve that slides between an inlet surface where the introduction port opens and an outlet surface where the injection port opens is formed in the check valve chamber, and the outer periphery of the free valve and the check valve chamber are provided. Between the sliding contact surface with the inner periphery, and between the opposing surfaces where the free valve and the outlet surface are in contact with each other, partially communicate from the inlet surface side of the check valve chamber to the opening of the injection port on the outlet surface, An injection device for a compressor, wherein a fluid passage is formed between an opposing surface of a free valve and an inlet surface in contact with an opening of an inlet. The injection device for a compressor according to claim 1 , wherein the check valve chamber and the free valve have a circular cross section, and a ratio L / D of a diameter D thereof to a thickness L of the free valve is 0.3 or more.

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