×

Displacement control device for variable displacement compressor

  • US 20030044291A1
  • Filed: 09/05/2002
  • Published: 03/06/2003
  • Est. Priority Date: 09/05/2001
  • Status: Active Grant
First Claim
Patent Images

1. A displacement control device for a variable displacement compressor in a refrigerant circuit of a vehicular air conditioner, wherein the compressor is driven by a drive source of the vehicle to compress refrigerant, wherein the refrigerant circuit includes a low pressure zone and a high pressure zone, the low pressure zone being exposed to the pressure of refrigerant drawn into the compressor, and the high pressure zone being exposed to the pressure of refrigerant compressed by the compressor, and wherein the displacement control device adjusts the pressure in a crank chamber of the compressor, thereby changing the displacement of the compressor, the control device comprising:

  • a bleed passage connecting the crank chamber with the low pressure zone;

    a first supply passage and a second supply passage, wherein the first and second supply passages connect the crank chamber with the high pressure zone, and wherein the first and second supply passages are formed independent from each other;

    a first control valve located in the first supply passage, wherein the first control valve adjusts the opening size of the first supply passage and includes a pressure sensitive member and a valve body, the pressure sensitive member being displaced in response to a pressure in the refrigerant circuit, the valve body being moved by the pressure sensitive member, wherein, in response to a pressure in the refrigerant circuit, the pressure sensitive member moves the valve body such that the displacement of the compressor is changed to cancel pressure fluctuation of a pressure in the refrigerant circuit; and

    a second control valve located in the second supply passage and in the bleed passage, wherein the second control valve operates in response to an external command and includes a first valve portion and a second valve portion, wherein the first valve portion adjusts the opening size of the second supply passage, and the second valve portion adjusts the opening size of the bleed passage, wherein, when the first valve portion decreases the opening size of the second supply passage, the second valve portion increases the opening size of the bleed passage, and wherein, when the first valve portion increases the opening size of the second supply passage, the second valve portion decreases the opening size of the bleed passage.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×