JP4359379B2 - Control valve for variable capacity compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control valve for a variable displacement compressor, and more particularly to a displacement control valve for a swash plate variable displacement compressor used in an in-vehicle air conditioner or the like.
[0002]
[Prior art]
As a capacity control valve for a swash plate type variable capacity compressor, as shown in Japanese Patent Publication No. 7-84865, Japanese Patent Laid-Open No. 5-99136, Japanese Patent Laid-Open No. 9-166606, an electromagnetic coil device is used. 2. Description of the Related Art An electromagnetic type variable displacement compressor control valve for controlling the displacement of a variable displacement compressor by controlling the crank chamber pressure of the variable displacement compressor according to the opening degree of the valve body that is driven to open and close has been known. In these conventional variable displacement compressor control valves, the valve portion is constituted by a ball valve, a needle valve, and a spool valve.
[0003]
[Problems to be solved by the invention]
In the conventional variable displacement compressor control valve in which the valve portion described above is composed of a ball valve and a needle valve, the valve element contacts the valve seat (seat) at an angle when the valve is closed. When the duty control in which the valve body is repeatedly seated is performed, there is a problem that the valve seat is deformed, the pressure balance is lost and the operating voltage is likely to increase, and the durability is inferior.
[0004]
Further, in a conventional variable displacement compressor control valve constituted by a spool valve, the valve element may contact the valve seat (seat) at an angle when the valve is closed, such as a ball valve or a needle valve. Since there is no pressure balance due to the deformation of the valve seat, the degree of close contact of the valve body with the valve seat is relatively low, and there is a problem that the valve leakage increases.
[0005]
The present invention has been made to solve the above-described problems, and it is not necessary to increase the size of the electromagnetic coil regardless of the increase in discharge pressure, and at the same time, a pressure balance can be achieved. It is an object of the present invention to provide a control valve for a variable displacement compressor in which a stopper structure having the above characteristics can be incorporated.
[0006]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, a control valve for a variable displacement compressor according to claim 1 comprises a suction port side passage, a crank chamber side passage, a discharge port side passage, the suction port side passage, A valve housing in which a suction pressure valve port for connecting the crank chamber side passage and a discharge pressure valve port for connecting the crank chamber side passage and the discharge port side passage are formed; the suction pressure valve port and the discharge pressure valve; The valve body is integrally provided so as to be movable in the valve housing so as to open and close the ports in a mutually opposite relationship, and the valve body is urged by a valve spring to close the suction pressure valve port. A valve chamber; a plunger chamber that is communicated with the suction pressure valve port and into which suction pressure is introduced; a plunger; and a winding portion. An electromagnetic coil device attached to one end of the valve housing for driving the valve rod so that the valve element closes the discharge pressure valve port against the valve spring by operating a valve The valve rod is driven by duty ratio control of the coil device, and the flow rate between the suction port side passage and the crank chamber side passage and the flow rate between the crank chamber side passage and the discharge port side passage per unit time according to the duty ratio. In the control valve for a variable displacement compressor for controlling the capacity of the variable displacement compressor by controlling the crank chamber pressure of the compressor based on the ratio of the valve rod, one end of the valve rod on the electromagnetic coil device side A first stopper for restricting a valve closing position of the valve body that contacts the electromagnetic coil device and closes the suction pressure valve port, and is provided at the other end of the valve rod. A second stopper for restricting the valve closing position of the valve body that contacts the stopper provided at the end and closes the discharge pressure valve port, and the first stopper communicates with the suction pressure valve port. The second stopper accommodates the discharge pressure valve port having a diameter equal to the valve seat diameter of the suction pressure valve port and the discharge pressure valve port in accordance with the valve diameter of the valve body, respectively. In addition, the suction pressure of the suction pressure valve port is exerted on the end surface of the second stopper .
[0007]
In order to achieve the above object, a variable displacement compressor control valve according to a second aspect of the present invention is the variable displacement compressor control valve according to the first aspect of the present invention, wherein the stopper portion is the second stopper. An adjustment screw member for adjusting the valve closing position of the valve body regulated by the stopper
It is characterized by that .
[0008]
According to the control valve for a variable displacement compressor according to the first aspect of the present invention, the valve housing includes a suction port side passage, a crank chamber side passage, a discharge port side passage, a suction port side passage, and a crank chamber side passage. Are formed, and a suction pressure valve port for connecting the crank chamber side passage and the discharge port side passage is formed. A valve stem integrally having a valve body movably provided in a valve housing so as to open and close the suction pressure valve port and the discharge pressure valve port in a mutually opposite relationship is a valve spring in a state where the valve body closes the suction pressure valve port. It is energized by. The electromagnetic coil device attached to one end portion of the valve housing has a plunger chamber, a plunger, and a winding portion that are communicated with the suction pressure valve port and into which the suction pressure is introduced. Actuates and drives the valve stem in a state where the valve body closes the discharge pressure valve port against the valve spring. The valve stem is driven by duty ratio control of the electromagnetic coil device, and the ratio between the flow rate between the suction port side passage and the crank chamber side passage and the flow rate between the crank chamber side passage and the discharge port side passage per unit time according to the duty ratio is determined. The capacity of the variable capacity compressor is controlled by controlling the crank chamber pressure of the compressor.
Teeth may, valve stem provided at one end of the valve stem of the electromagnetic coil device side, a first stopper for regulating the valve-closed position of the valve body that closes the intake valve port in contact with the electromagnetic coil device, the A second stopper that is provided at the other end of the valve stem and that abuts against a stopper provided at the other end of the valve housing to restrict the valve closing position of the valve body that closes the discharge pressure valve port; An empty space in which the first stopper communicates with the suction pressure valve port, and the second pressure stopper extends the discharge pressure valve port having a diameter equal to the valve seat diameter of the valve body and the valve seat diameter of the discharge pressure valve port. together are accommodated, respectively at the second though the suction pressure of the suction valve port on the end face of the stopper is exerted, it is rather Na breaking the pressure balance, moreover, does not occur biting into the valve seat surface of the valve body .
[0009]
According to the control valve for a variable displacement compressor according to the invention of claim 2, the stopper portion is composed of an adjusting screw member for adjusting a valve closing position of the valve body regulated by the second stopper, The restriction position of the valve stem, which is driven in a state where the plunger is actuated by energizing the wire portion and the valve body closes the discharge pressure valve port, can be adjusted .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0011]
1 to 3 show a variable displacement compressor control valve according to an embodiment.
[0012]
The variable displacement compressor control valve 10 has a cylindrical valve housing 11. The valve housing 11 is composed of an upper housing 11A and a lower housing 11B connected by screws or caulking, and the valve housing 11 includes a suction port extending across the intermediate portion of the valve housing 11 in the radial direction. Side passage 12, crank chamber side passage 13, discharge port side passage 14, suction pressure valve port 15 connecting the suction port side passage 12 and crank chamber side passage 13, and crank chamber side passage 13 and discharge port side passage 14. And a discharge pressure valve port 16 that communicates with each other.
[0013]
The valve housing 11 is provided with a valve rod 18 that integrally has a valve body 17 that opens and closes a suction pressure valve port 15 and a discharge pressure valve port 16 in a mutually opposing relationship. In this embodiment, the opening degree of the suction pressure valve port 15 is reduced by the upward movement of the valve body 17 and the opening degree of the discharge pressure valve port 16 is increased. On the contrary, the suction pressure valve port 15 is moved by the downward movement of the valve body 17. The opening degree of 15 increases and the opening degree of the discharge pressure valve port 16 decreases.
[0014]
An adjustment screw member 19 is threadedly engaged with the lower end portion of the valve housing 11, and the valve spring is interposed between the adjustment screw member 19 and a lower stopper 20 as a second stopper formed at the lower end of the valve stem 18. 21 is provided, and the valve spring 21 urges the valve rod 18 upward. Between the adjusting screw member 19 and the lower stopper 20, a spring chamber 22 for accommodating the valve spring 21 is also defined as a void extending the discharge pressure valve port 16 for accommodating the second stopper. 11 is formed with a suction pressure introduction port 23 for introducing the suction pressure Ps of the compressor into the spring chamber 22 for pressure balance.
[0015]
An electromagnetic coil device 24 is attached to the upper end portion of the valve housing 11. The electromagnetic coil device 24 includes a suction element 25 fixed to the valve housing 11, a lower cover 26 fixed to the suction element 25, a plunger tube 27 fixed to the suction element 25, and an outer part fixed to the lower cover 26. The box 27A, the coil bobbin 28 fixed inside the outer box 27A, the winding portion 29, the magnetic guide member 30, the plug member 31 that covers the plunger tube 27, and the plunger tube 27 (plunger chamber 32) move up and down. The plunger 33 is provided, and the plunger spring 34 is provided between the plug member 31 and the plunger 33.
[0016]
A center hole 35 is formed through the suction element 25, and a connecting rod 36 that connects the plunger 33 and the valve rod 18 is fitted in the center hole 35 so as to be movable up and down.
[0017]
The suction port side passage 12 is a gap between the upper stopper 37 as a first stopper formed at the upper end of the valve rod 18 and the fitting hole 38 of the valve housing 11 that receives the upper stopper 37, the connecting rod 36 and the suction. The plunger 25 communicates with the plunger chamber 32 through a gap with the center hole 35 of the child 25, and a pressure equalizing hole (through hole) 39 is formed in the plunger 33.
[0018]
Lower stopper 20 top facing of the stopper portion 40 of the adjusting screw member 19, the most-lowered position of the valve rod 18 abuts against the stopper portion 40, i.e., a discharge valve port 16 closed valve position of the closes the valve body 17 Is stipulated. Further, the upper stopper 37 faces the lower bottom surface of the attracting element 25 and abuts against the attracting element 25 constituting a part of the electromagnetic coil device 24 to close the highest position of the valve rod 18 , that is, the suction pressure valve port 15. The valve closing position of the valve body 17 is defined.
[0019]
Next, the operation of the variable displacement compressor control valve 10 having the above-described configuration will be described.
Duty ratio control of the electromagnetic coil device 24, i.e., more power control per unit time, the valve rod 1 8 comprising valve body 17 by the equilibrium relationship between the generated load and the spring load of the valve spring 21 of the electromagnetic coil device 24 and above downward, opening per unit time of the intake valve ports 1 5 and a discharge valve port 16 according to the duty ratio is increased or decreased by one another mutually contradictory. As a result, the flow rate between the suction port side passage 12 and the crank chamber side passage 13 and the flow rate between the crank chamber side passage 13 and the discharge port side passage 14 increase or decrease, and the flow rate between Pd-Pc and Pc-Ps The crank chamber pressure of the compressor is controlled by the ratio with the inter-flow rate, and the capacity control of the variable capacity compressor is performed.
[0020]
When the coil of the electromagnetic coil device 24 is not energized, as shown in the figure, the suction pressure valve port 15 is fully closed and the discharge pressure valve port 16 is fully opened, so that the variable displacement compressor is in a full unload operation state. Become.
[0021]
The suction pressure Ps of the compressor enters the plunger chamber 32 from the suction port side passage 12 through a gap between the upper stopper 37 and the fitting hole 38 and a gap between the connecting rod 36 and the center hole 35. As a result, the suction pressure Ps of the compressor is introduced into the plunger chamber 32.
[0022]
Further, the lowest lowered position of the valve stem 18 is defined by the lower stopper 20 and the stopper portion 40 of the adjusting screw member 19, and the highest raised position of the valve stem 18 is defined by the upper stopper 37 and the suction element 25. , necessary to provide the stopper function (the flange diameter at the expense of pressure balance valve body 17 to be sufficiently larger than the seat diameter) in the valve body 17 I is Do not, the valve diameter D14 to the seat diameter D11 or D12 As shown in FIG. 2, the upper stopper 37 is connected to the suction pressure valve port 15 including the fitting hole 38, and the lower stopper 20 is connected to the valve seat valve diameters D11 and D12. The discharge pressure valve port 16 having the same diameter D13 is accommodated in the extended space, and the suction pressure of the suction pressure valve port 15 is applied to the end surface of the lower stopper 20. Accordingly, it becomes possible to be exerted the same suction pressure Ps in the upper and lower ends of the valve rod 18 can take the full pressure balanced construction so that it can be a D11 = D12 = D13 (= D14 ).
[0023]
As a result, the pressure effect on the valve body 17 can be eliminated, and the valve opening characteristic is not affected even when the discharge pressure Pd becomes high, and the electromagnetic coil device 24 is reduced by reducing the valve driving force. Miniaturization is possible.
[0024]
Further, in the case where there is no upper and lower stopper mechanism as described above, if the valve diameter D14 is set to a substantially seat diameter D11 or D12, the durability decreases due to biting into the seat surface of the valve body. by provided, be made the duty ratio control, without the valve body 17 bites into the narration over up surface 41 (see FIG. 3), the original high pressure resistance, durability of these portions Sex is secured.
[0028]
【The invention's effect】
As understood from the above description, according to the variable displacement compressor control valve according to the invention of claim 1, rather name can break the pressure balance, moreover, does not occur biting into the valve seat surface of the valve body Therefore, it is no longer necessary to increase the size of the electromagnetic coil device even when the discharge pressure becomes high in a supercritical vapor compression refrigeration cycle device that uses a refrigerant such as CO ₂ , and a compact design is possible. Thus, sufficient durability in duty control can be obtained.
[0029]
According to the control valve for a variable displacement compressor according to the second aspect of the present invention, since the restriction position of the valve rod when the plunger is operated can be adjusted, more sufficient durability can be obtained .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a control valve for a variable displacement compressor according to the present invention.
FIG. 2 is an enlarged cross-sectional view showing a main part of an embodiment of a control valve for a variable displacement compressor according to the present invention.
FIG. 3 is an enlarged cross-sectional view of a portion B in FIG .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Control valve for variable displacement type compressor 11 Valve housing 12 Suction port side passage 13 Crank chamber side passage 14 Discharge port side passage 15 Suction pressure valve port 16 Discharge pressure valve port 17 Valve element 18 Valve rod
19 Adjustment screw member 20 Lower stopper (second stopper)
21 Valve spring 23 Suction pressure introduction port 24 Electromagnetic coil device 25 Suction element 27 Plunger tube 29 Winding part 32 Plunger chamber 33 Plunger 37 Upper stopper (first stopper)
40 stopper portion

Claims (2)

A suction port side passage, a crank chamber side passage, a discharge port side passage, a suction pressure valve port that connects the suction port side passage and the crank chamber side passage, and the crank chamber side passage and the discharge port side passage. A valve housing formed with a discharge pressure valve port to be connected in communication, and a valve body movably provided in the valve housing so as to open and close the intake pressure valve port and the discharge pressure valve port in a mutually opposing relationship And a valve rod urged by a valve spring so that the valve body closes the suction pressure valve port, a plunger chamber communicated with the suction pressure valve port and introduced with suction pressure, a plunger, and a winding The valve body is in a state where the valve body closes the discharge pressure valve port against the valve spring by operating the plunger by energizing the winding portion. An electromagnetic coil device attached to one end of the valve housing for driving the valve shaft, the valve rod is driven by duty ratio control of the electromagnetic coil device, and the suction port side passage per unit time according to the duty ratio -Capacity variable compression that controls the capacity of the variable capacity compressor by controlling the crank chamber pressure of the compressor by the ratio of the flow rate between the crank chamber side passage and the crank chamber side passage-the flow rate between the discharge port side passages. In machine control valves,
A first stopper that restricts a valve closing position of the valve body that is provided at one end of the valve rod on the electromagnetic coil device side and contacts the electromagnetic coil device to close the suction pressure valve port; A second stopper that is provided at the other end of the valve stem and that abuts against a stopper provided at the other end of the valve housing to restrict the valve closing position of the valve body that closes the discharge pressure valve port; Have
In the space where the first stopper communicates with the suction pressure valve port, the second stopper has a diameter equal to the valve seat diameter of the suction pressure valve port and the discharge pressure valve port adjusted to the valve diameter of the valve body. A control valve for a variable displacement compressor, wherein the discharge pressure valve port is accommodated in an empty space, and the suction pressure of the suction pressure valve port is exerted on the end surface of the second stopper . The stopper portion is composed of an adjusting screw member that adjusts the valve closing position of the valve body regulated by the second stopper.
The control valve for a variable displacement compressor according to claim 1 .

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