VARIABLE-CAPACITY COMPRESSOR CONTROL VALVE

Abstract

Provided is a variable-capacity compressor control valve that can effectively reduce sliding resistance while preventing Pd-Ps leakage and the inclination of a valve element, thus increasing controllability and operation stability, and can also avoid operation failures or troubles caused by foreign matter. A sliding portion of a main valve element that is slidably fitted and inserted into a guide hole provided in a valve body includes an upper small-clearance portion and a lower small-clearance portion in the opposite ends in a vertical direction thereof and a large-clearance portion between the upper small-clearance portion and the lower small-clearance portion. The upper small-clearance portion and the lower small-clearance portion each has a diameter Dx and a vertical length that is equal to or larger than a predetermined length. The large-clearance portion has a diameter Dy that is smaller than the Dx and a vertical length of 1 mm or larger.

Claims

1. A variable-capacity compressor control valve, comprising: a valve body including a valve chamber with a valve orifice, a Ps inlet/outlet port communicating with a suction chamber of a compressor, a Pd introduction port arranged upstream of the valve orifice and communicating with a discharge chamber of the compressor, and a Pc inlet/outlet port arranged downstream of the valve orifice and communicating with a crank chamber of the compressor; a valve element for opening or closing the valve orifice; an electromagnetic actuator adapted to move the valve element in a direction to open or close the valve orifice; a pressure-sensitive chamber adapted to receive a suction pressure Ps from the compressor via the Ps inlet/outlet port; and a pressure-sensitive reaction member adapted to urge the valve element in the direction to open or close the valve orifice in accordance with a pressure in the pressure-sensitive chamber, wherein a sliding portion of the valve element is slidably fitted and inserted into a guide hole provided in the valve body, the sliding portion including small-clearance portions in opposite ends in an axial direction thereof and one or more large-clearance portions between the small-clearance portions in the opposite ends, the small-clearance portions each having a diameter Dx and an axial length that is equal to or larger than a predetermined length, the one or more large-clearance portions each having a diameter Dy that is smaller than the Dx and an axial length of 1 mm or larger, and a space formed between the guide hole of the valve body and the one or more large-clearance portions of the valve element communicates with all of the suction chamber, the discharge chamber, and the crank chamber of the compressor such that leakage of fluid occurs only through a gap formed between the guide hole of the valve body and the small-clearance portions in the opposite ends of the sliding portion of the valve element.

2. The variable-capacity compressor control valve according to claim 1, wherein when a plurality of the large-clearance portions are separately provided between the small-clearance portions in the opposite ends, an intermediate small-clearance portion is provided between the large-clearance portions, the intermediate small-clearance portion having the diameter Dx and an axial length that is equal to or larger than a predetermined length.

3. The variable-capacity compressor control valve according to claim 1, wherein of the small-clearance portions in the opposite ends, the small-clearance portion on a low-pressure side has an axial length that is smaller than an axial length of the small-clearance portion on a high-pressure side.

4. The variable-capacity compressor control valve according to claim 1, wherein a sum of axial lengths of the one or more large-clearance portions is equal to or larger than ⅓ of a total length of the sliding portion.

5. The variable-capacity compressor control valve according to claim 1, wherein of the small-clearance portions in the opposite ends, the small-clearance portion on a low-pressure side has a discharge groove for discharging foreign matter accumulated in the one or more large-clearance portions to a low-pressure side.

6. The variable-capacity compressor control valve according to claim 5, wherein the discharge groove includes one or more vertical grooves or helical grooves.

7. The variable-capacity compressor control valve according to claim 1, wherein of the small-clearance portions in the opposite ends, the small-clearance portion on a high-pressure side has an annular groove for capturing foreign matter, the annular groove having a width of 0.5 mm or smaller.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0043] FIG. 1 is a general vertical cross-sectional view of a first embodiment of the variable-capacity compressor control valve according to the present invention.

[0044] FIG. 2 is an enlarged vertical cross-sectional view of a main part of the first embodiment of the variable-capacity compressor control valve according to the present invention.

[0045] FIG. 3 is an enlarged vertical cross-sectional view of a main part of a second embodiment of the variable-capacity compressor control valve according to the present invention.

[0046] FIG. 4 is an enlarged vertical cross-sectional view of a main part of a third embodiment of the variable-capacity compressor control valve according to the present invention.

[0047] FIG. 5A is an enlarged side view showing an upper portion of a main valve element, for explaining modifications of the embodiments of the variable-capacity compressor control valve according to the present invention.

[0048] FIG. 5B is an enlarged side view showing an upper portion of a main valve element, for explaining modifications of the embodiments of the variable-capacity compressor control valve according to the present invention.

[0049] FIG. 6 is a general vertical cross-sectional view of an example of a conventional variable-capacity compressor control valve.

[0050] FIG. 7 is an enlarged vertical cross-sectional view of a main part of the control valve illustrated in FIG. 6.

DESCRIPTION OF EMBODIMENTS

[0051] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0052] FIG. 1 is a general vertical cross-sectional view of a first embodiment of the variable-capacity compressor control valve according to the present invention. FIG. 2, FIG. 3, and FIG. 4 are enlarged cross-sectional views of main parts of the first, second, and third embodiments of the variable-capacity compressor control valve according to the present invention, respectively. The general configuration of the first, second, and third embodiments (i.e., the configuration of the valve body 20, the electromagnetic actuator 30, the bellows device 40, etc.) (see FIG. 1) is basically the same as that of the conventional control valve 1′, which has been described with reference to FIG. 6 and FIG. 7. Therefore, the corresponding portions are denoted by the same reference numerals, and the repeated description will be omitted. The following discusses the differences from the conventional control valve 1′ for each of the embodiments, that is, the characteristic portions of the embodiments of the present invention.

[0053] It should be noted that the detailed general configuration and the operations of each of the first, second, and third embodiments are described in detail in the aforementioned Patent Literature 1 (with a sub valve element) or Patent Literature 2 (without a sub valve element). Thus, their descriptions are cited by reference and will replace the disclosure in this specification.

[0054] It should be noted that in the present specification, descriptions indicating the positions or directions, such as upper, lower, top, bottom, left, right, front, and rear, are used for the sake of convenience in accordance with the drawings to avoid complexity in the description, but such descriptions do not necessarily indicate the actual positions or directions when the control valve of the present invention is incorporated into a compressor.

[0055] In addition, in each drawing, a gap formed between some members, a clearance between some members, and the like may be depicted larger or smaller than their actual dimensions to help understand the invention and also for the sake of convenience to create the drawing.

First Embodiment

[0056] In a control valve 1 of the first embodiment illustrated in FIG. 1 and FIG. 2, the sliding portion 15e of the main valve element 15, which is slidably fitted and inserted into the guide hole 19 provided in the valve body 20 (or the internal-fitting member 20B thereof), includes an upper small-clearance portion 61 in its upper end and a lower small-clearance portion 62 in its lower end, in which the upper small-clearance portion 61 has a diameter Dx and a vertical length L1, and the portion of the lower small-clearance portion 62 except two annular grooves 51 each having a width of 0.5 mm or smaller has a diameter Dx and a vertical length L2. The sliding portion 15e of the main valve element 15 includes a large-clearance portion 71 between the upper small-clearance portion 61 and the lower small-clearance portion 62, in which the large-clearance portion 71 has a diameter Dy that is smaller than the Dx.

[0057] The diameter Dx of the upper small-clearance portion 61 and the lower small-clearance portion 62 is equal to the diameter of the sliding portion 15e of the conventional control valve 1′, which has been described with reference to FIG. 6 and FIG. 7. Only the upper small-clearance portion 61 and the lower small-clearance portion 62 slide into contact with the inner peripheral surface of the guide hole 19, and the large-clearance portion 71 having a diameter Dy smaller than the Dx does not slide into contact with the inner peripheral surface of the guide hole 19.

[0058] Further, a gap between the large-clearance portion 71 (or the outer peripheral surface of the sliding portion 15e in the large-clearance portion 71) and the inner peripheral surface of the guide hole 19 has a size significantly larger than the size of foreign matter that passes through a filter member 25A, for example (in other words, not smaller than the mesh size of the filter member 25A). Thus, even when the foreign matter enters into the large-clearance portion 71 through the lower small-clearance portion 62, the gap will not be clogged with the foreign matter when accumulated.

[0059] The vertical length U1 of the large-clearance portion 71 is set to 1 mm or larger, and in this example, about ⅔ of the total length L0 of the sliding portion 15e.

[0060] Further, the upper side of the guide hole 19 is a low-pressure side (adjacent to the Ps inlet/outlet chamber 28, the Ps inlet/outlet ports 27, the plunger 37), and the lower side of the guide hole 19 is a high-pressure side (adjacent to the Pd introduction ports 25, the valve orifice 22), and the vertical length L1 of the upper small-clearance portion 61 on the low-pressure side is smaller than the vertical length L2 of the lower small-clearance portion 62 on the high-pressure side. The sum of the vertical length L1 of the upper small-clearance portion 61 and the vertical length L2 of the lower small-clearance portion 62 is ¼ to ⅓ of the total length L0 of the sliding portion 15e in this example.

[0061] In the control valve 1 of the present embodiment with the above-described configuration, the sliding portion 15e includes, in its upper and lower ends respectively, the upper small-clearance portion 61 and the lower small-clearance portion 62, which slide into contact with the inner peripheral surface of the guide hole 19, and the large-clearance portion 71, which does not slide into contact with the inner peripheral surface of the guide hole 19, between the upper small-clearance portion 61 and the lower small-clearance portion 62. Thus, the sliding area is smaller than that of the conventional control valve 1′, in which the sliding portion 15e does not include a large-clearance portion, and the control valve 1 of the present embodiment can reduce the sliding resistance.

[0062] In addition, since the sliding portion 15e has the total length L0 that is equal to that of the conventional control valve and includes, in its upper and lower ends, the small-clearance portions (i.e., the upper small-clearance portion 61, the lower small-clearance portion 62), which clearances at its upper and lower ends are equal to those of the conventional control valve, the control valve 1 of the present embodiment can prevent the increase in the amount of Pd-Ps leakage and prevent the inclination of the main valve element 15 as in the conventional control valve.

[0063] In addition, since the clearance formed in the large-clearance portion 71 is set significantly larger than the size of the foreign matter, even when the foreign matter enters into the large-clearance portion 71 through the lower small-clearance portion 62, the clearance will not be clogged with the foreign matter when accumulated.

[0064] In view of the above, the control valve 1 of the present embodiment can effectively reduce the sliding resistance while preventing the Pd-Ps leakage and the inclination of the valve element, thus increasing controllability and operation stability, and can also avoid operation failures or troubles caused by foreign matter.

[0065] It should be noted that the following countermeasures may be taken in order to further avoid operation failures or troubles caused by foreign matter. Specifically, as illustrated in FIG. 5A, the upper small-clearance portion 61 may include one or more vertical grooves 53 each having a width of 0.5 mm or smaller as a discharge groove for discharging foreign matter accumulated in the large-clearance portion 71 to the low-pressure side (adjacent to the Ps inlet/outlet chamber 28, the Ps inlet/outlet ports 27, the plunger 37). Furthermore, as illustrated in FIG. 5B, the upper small-clearance portion 61 may include one or more helical grooves 54 each having a width of 0.5 mm or smaller as a discharge groove for discharging foreign matter accumulated in the large-clearance portion 71 to the low-pressure side (adjacent to the Ps inlet/outlet chamber 28, the Ps inlet/outlet ports 27, the plunger 37).

Second Embodiment

[0066] As in the first embodiment, in a control valve 2 of the second embodiment illustrated in FIG. 3, the sliding portion 15e of the main valve element 15 includes an upper small-clearance portion 61 in its upper end and a lower small-clearance portion 62 in its lower end, in which the upper small-clearance portion 61 has a diameter Dx and a vertical length L1, and the portion of the lower small-clearance portion 62 except two annular grooves 51 each having a width of 0.5 mm or smaller has a diameter Dx and a vertical length L2. Further, the sliding portion 15e of the main valve element 15 includes a large-clearance portion 72, an intermediate small-clearance portion 63, and a large-clearance portion 73 between the upper small-clearance portion 61 and the lower small-clearance portion 62, in which the large-clearance portion 72 has a diameter Dy that is smaller than the Dx, the intermediate small-clearance portion 63 has the diameter Dx that is equal to those of the upper small-clearance portion 61 and the lower small-clearance portion 62 and a vertical length L3, and the large-clearance portion 73 has the diameter Dy that is equal to that of the large-clearance portion 72.

[0067] In other words, in the present embodiment, the two separate large-clearance portions 72, 73 each having a diameter Dy that is smaller than the Dx and a vertical length U2 (1 mm or larger) are provided between the upper small-clearance portion 61 and the lower small-clearance portion 62, and the intermediate small-clearance portion 63 having the diameter Dx and a vertical length L3 is provided between the two large-clearance portions 72, 73.

[0068] In this example, the sum of the vertical lengths (U2×2) of the two large-clearance portions 72, 73 is ½ to ⅗ of the total length L0 of the sliding portion 15e, and in this example, the sum of the vertical length L1 of the upper small-clearance portion 61, the vertical length L2 of the lower small-clearance portion 62, and the vertical length L3 of the intermediate small-clearance portion 63 is ⅖ to ½ of the total length L0 of the sliding portion 15e.

[0069] It should be noted that the diameter of the intermediate small-clearance portion 63 may not be equal to the diameter of the upper small-clearance portion 61 and the lower small-clearance portion 62. Further, the two large-clearance portions 72, 73 may not have the same diameter. Further, it is needless to mention that the vertical length L1 of the upper small-clearance portion 61, the vertical length L2 of the lower small-clearance portion 62, the vertical length L3 of the intermediate small-clearance portion 63, and the vertical length U2 of the large-clearance portions 72, 73 may not be limited to the illustrated examples. It is also needless to mention that the two large-clearance portions 72, 73 may not have the same vertical length.

[0070] Also in the control valve 2 of the present embodiment with the above-described configuration, an operational advantage that is substantially equal to that in the first embodiment may be produced. Also in the second embodiment, the sum of the vertical lengths (U2×2) of the two large-clearance portions 72, 73 is equal to or larger than ⅓ of the total length L0 of the sliding portion 15e, but is smaller than the vertical length U1 of the large-clearance portion 71 of the first embodiment. The sum of the vertical lengths of the small-clearance portions is set larger due to the intermediate small-clearance portion 63. Therefore, the sliding resistance is slightly higher than that of the first embodiment, but the amount of Pd-Ps leakage can be slightly reduced in the control valve 2 of the present embodiment.

Third Embodiment

[0071] As in the first and second embodiments, in a control valve 3 of the third embodiment illustrated in FIG. 4, the sliding portion 15e of the main valve element 15 includes an upper small-clearance portion 61 in its upper end and a lower small-clearance portion 62 in its lower end, in which the upper small-clearance portion 61 has a diameter Dx and a vertical length L1, and the portion of the lower small-clearance portion 62 except two annular grooves 51 each having a width of 0.5 mm or smaller has a diameter Dx and a vertical length L2. Further, the sliding portion 15e of the main valve element 15 includes three separate large-clearance portions 74, 75, 76, each having a diameter Dy that is smaller than the Dx and a vertical length U3 (1 mm or larger), between the upper small-clearance portion 61 and the lower small-clearance portion 62. Also, the sliding portion 15e of the main valve element 15 includes intermediate small-clearance portions 64, 65 between the large-clearance portions 74 to 75 and the large-clearance portions 75 to 76, respectively, the intermediate small-clearance portions 64, 65 each having the diameter Dx that is equal to those of the upper small-clearance portion 61, the lower small-clearance portion 62, and the intermediate small-clearance portion 63 and having vertical lengths L4, L5, respectively.

[0072] In this example, the sum of the vertical lengths (U3×3) of the three large-clearance portions 74, 75, 76 is about ½ of the total length L0 of the sliding portion 15e, and in this example, the sum of the vertical length L1 of the upper small-clearance portion 61, the vertical length L2 of the lower small-clearance portion 62, and the vertical lengths L4, L5 of the intermediate small-clearance portions 64, 65 is ⅓ to ½ of the total length L0 of the sliding portion 15e.

[0073] It should be noted that it is needless to mention that the diameter of the intermediate small-clearance portions 64, 65, the diameter of the three large-clearance portions 74, 75, 76, the vertical length L1 of the upper small-clearance portion 61, the vertical length L2 of the lower small-clearance portion 62, the vertical lengths L4, L5 of the intermediate small-clearance portions 64, 65, and the vertical length U3 of the large-clearance portions 74, 75, 76 are not limited to the illustrated examples.

[0074] Also in the control valve 3 of the present embodiment with the above-described configuration, an operational advantage that is substantially equal to those in the first and second embodiments may be produced. Also in the third embodiment, the sum of the vertical lengths (U3×3) of the three large-clearance portions 74, 75, 76 is equal to or larger than ⅓ of the total length of the sliding portion 15e, but is smaller than the vertical length of the large-clearance portion of the first and second embodiments. Further, the sum of the vertical lengths of the small-clearance portions is set larger due to the intermediate small-clearance portions 64, 65. Therefore, the sliding resistance is slightly higher than that of the first and second embodiments, but the amount of Pd-Ps leakage can be slightly reduced in the control valve 3 of the present embodiment.

REFERENCE SIGNS LIST

[0075] 1 Variable-capacity compressor control valve (first embodiment) [0076] 2 Variable-capacity compressor control valve (second embodiment) [0077] 3 Variable-capacity compressor control valve (third embodiment) [0078] 10 Valve body [0079] 11 Main valve unit [0080] 12 Sub valve unit [0081] 15 Main valve element [0082] 15e Sliding portion [0083] 16 In-valve release passage [0084] 16A Release through-hole [0085] 17 Sub valve element [0086] 19 Guide hole [0087] 20 Valve body [0088] 20A Body member [0089] 20B Internal-fitting member [0090] 22 Valve orifice [0091] 25 Pd introduction port [0092] 26 Pc inlet/outlet chamber (inlet/outlet port) [0093] 27 Ps inlet/outlet port [0094] 28 Ps inlet/outlet chamber [0095] 30 Electromagnetic actuator [0096] 32 Coil [0097] 37 Plunger [0098] 40 Bellows device (pressure-sensitive reaction member) [0099] 45 Pressure-sensitive chamber [0100] 46 Pushrod [0101] 47 Plunger spring (valve-opening spring) [0102] 50 Valve-closing spring [0103] 51 Annular groove for capturing foreign matter [0104] 53 Vertical groove (discharge groove) for discharging foreign matter [0105] 54 Helical groove (discharge groove) for discharging foreign matter [0106] 61 Upper small-clearance portion [0107] 62 Lower small-clearance portion [0108] 63 to 65 Intermediate small-clearance portion [0109] 71 to 76 Large-clearance portion