JP2011241896A - Control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control valve for a variable capacity type compressor that can avoid the clogging of foreign matters in a slide face gap formed between, in particular, a shaft of a valve rod and a guide hole, and hardly causes an operation malfunction or the like of the valve rod resulting from the foreign matters.SOLUTION: A guide pressure-insertion hole 55 has, in an ascending order, a large diameter hole 55a, a conical face 55b and a small diameter hole 55c. A cylindrical guide 54 has, in an ascending order, a pressure insert 54a pressure-inserted into the large diameter hole 55a, an intermediate part 54b smaller than the pressure insert 54a in diameter, a shoulder 54c whose external peripheral angular part 54e is made to substantially line-contact with the conical face 55b over the whole circumference, and a small diameter part 54d. A slide part (Lb portion) of a lower-side shaft 15e with respect to a lower-side guide hole 19B is made not to overlap with the pressure insert 54a (La portion) when viewed in the axial direction.

Description

  The present invention relates to a control valve for a variable displacement compressor used in a car air conditioner and the like, and in particular, foreign matter (remaining from the time of processing and assembly) clogged in a sliding surface gap formed between a valve stem and a guide hole. The present invention relates to a control valve for a variable displacement compressor that is less likely to cause a malfunction of a valve stem due to cutting abrasive scraps, abrasives, abrasion powder due to sliding friction, dust from the outside, and the like.

  Generally, a control valve for a variable displacement compressor used in a car air conditioner or the like introduces a refrigerant having a discharge pressure Pd from the compressor and adjusts the discharge pressure in order to adjust the pressure Pc in the crank chamber of the compressor. The refrigerant of Pd is squeezed and led out to the crank chamber, and the lead-out amount (throttle amount) to the crank chamber is controlled according to the suction pressure Ps of the compressor.

  As such a variable displacement compressor control valve, the inventors of the present application have previously proposed a control valve as shown in FIG. Hereinafter, the illustrated control valve 5 will be briefly described (see also Patent Document 1 below). The control valve 5 basically includes a valve rod 15, guide holes 19A and 19B into which the valve rod 15 is slidably inserted, and a discharge pressure port (Pd for introducing discharge pressure from the compressor). Hole) 25, control pressure port (Pc hole) 26 communicating with the crank chamber of the compressor, valve body 20 provided with suction pressure introduction portions 72 and 70 for introducing the suction pressure Ps of the compressor, and the valve An electromagnetic actuator 30 including an attractor 34 and a plunger 37 for driving the rod 15 in the opening / closing direction of the valve port 22 and the valve rod 15 in the valve port opening / closing direction in response to the suction pressure Ps of the compressor. And a pressure sensitive member 40 such as a bellows 41 to be driven.

  More specifically, the illustrated control valve 5 includes a valve rod 15 that is integrally connected to the operation rod 14. The valve stem 15 includes an upper shaft portion 15c, a small diameter shaft portion 15b having a smaller diameter than the upper shaft portion 15c, a valve body portion 15a having a larger diameter than the upper shaft portion 15c, and a lower side having the same diameter as the upper shaft portion 15c. It has a shaft portion 15e. A lower end portion (concave hole portion) 14b of the operating rod 14 is connected and fixed to the upper portion (convex portion) of the valve rod 15 by press fitting or the like, and an annular groove portion (small diameter portion) 15d is provided below the connection fixing portion. At the same time, a locking portion 38 provided at the bottom of the plunger 37 is fitted into the annular groove 15d so that the valve stem 15 and the plunger 37 can be moved up and down integrally.

  On the other hand, the valve body 20 is provided with a valve port (valve seat portion) 22 with which the valve body portion 15a contacts and separates, and a guide press-fitting hole 53 with a larger diameter is provided below the valve port 22. A cylindrical guide 52 that forms a lower guide hole 19B into which the lower shaft portion 15e of the valve rod 15 is slidably fitted is inserted into and fixed to the lower half of the guide press-fitting hole 53 by press-fitting. A portion above the cylindrical guide 52 in the guide press-fitting hole 53 is a valve chamber 21.

  In the valve chamber 21, a discharge pressure port (Pd hole) 25 having a circular cross section for introducing the discharge pressure Pd from the compressor is opened. Two Pd holes 25 are arranged opposite to each other with an interval of 180 degrees.

  Further, on the upper side across the valve port 22 in the valve body 20, a control pressure port (Pc hole) 26 for controlling Pc communicates with the crank chamber (pressure Pc) of the compressor. Two are arranged opposite to each other with an interval (provided so as to cross through the valve body 20). The Pc holes 26 are circular in cross section, and their inner ends are opened to the lower part (Pc chamber 26S) of the upper guide hole 19A.

  On the other hand, a suction pressure introduction chamber 72 (same diameter as the lower guide hole 19B) into which the suction pressure Ps is introduced is provided at the lower end portion of the lower guide hole 19B in the cylindrical body 52, and the valve body 20 is provided with the same. In order to guide the suction pressure Ps to the pressure sensitive chamber 45 (the bellows body 40), a suction pressure passage 70 including linear through holes (small diameter hole 70a and large diameter hole 70b) is provided. One end (upper end) of the suction pressure passage 70 communicates with the pressure sensing chamber 45 via the plunger chamber 24, and the other end is opened at the lower end portion of the valve body 20.

Japanese Patent Application No. 2009-028080

  In the control valve 5 as described above, as shown in an enlarged view in FIG. 2A, a cylindrical shape that forms a lower guide hole 19B into which the lower shaft portion 15e of the valve rod 15 is slidably fitted. The guide 52 includes a press-fit portion 52a (length La) that is press-contacted to the inner peripheral surface of the guide press-fit hole 53, an upper small-diameter portion 52c, and a shoulder portion 52b therebetween. A sliding surface gap α (exaggerated in the drawing) is formed between the inner peripheral surface of the lower guide hole 19B and the outer peripheral surface of the lower shaft portion 15e of the valve stem 15. The figure shows a state where the valve stem 15 (lower shaft portion 15e) is in the lowest lowered position (fully opened state), and the lower end of the lower shaft portion 15e is slightly above the lower end of the cylindrical guide 52. It is located in. In this case, the sliding portion length Lb of the lower shaft portion 15e with respect to the lower guide hole 19B is the length from the lower end of the lower shaft portion 15e to the upper end of the cylindrical guide 52.

  By the way, in the control valve 5, the inner diameter of the cylindrical guide 52, that is, the diameter of the lower guide hole 19 </ b> B is set to a dimension that takes into account reduction by press-fitting in advance, and initially has the same dimension from the upper end to the lower end. However, when the cylindrical guide 52 is press-fitted into the guide press-fitting hole 53, the inner diameter of the press-fit portion 52a is reduced, but the inner diameter of the upper portion (small diameter portion 52c) is not reduced. Further, the sliding surface gap α is widened on the upper side of the cylindrical guide 52, and a larger foreign matter M (cut polishing remaining from the time of processing assembly) is formed in the gap α. Scraps, abrasives, abrasion powder due to sliding friction, etc.) easily enter, and the sliding surface gap α becomes narrow near the upper end of the press-fit portion 52a, so that the foreign matter M tends to accumulate in the middle of the sliding portion and become clogged.

  As described above, when the foreign matter M is clogged in the sliding surface gap α, the sliding resistance of the valve stem 15 increases and the valve stem 15 malfunctions, for example, even if the suction element 34 generates a normal suction force. In some cases, the valve stem 15 does not move upward, and in this case, the valve opening is not adjusted appropriately. The actual condition is that foreign matters that cause such a problem cannot be completely removed even if a filter or the like is attached.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to prevent foreign matters from clogging in the sliding surface gap formed between the shaft portion of the valve stem and the guide hole, Accordingly, it is an object of the present invention to provide a control valve for a variable displacement compressor that is unlikely to cause a malfunction of a valve stem due to foreign matters.

  In order to achieve the above object, a control valve according to the present invention basically includes a valve stem having a valve body portion and a shaft portion, and a valve main body for slidably holding the valve stem, The valve body is provided with a guide press-fitting hole, and a cylindrical guide that forms a guide hole into which the shaft portion of the valve rod is slidably fitted is inserted and fixed to one end of the guide press-fitting hole by press-fitting. In addition, the press-fitting portion of the cylindrical guide into the guide press-fitting hole and the sliding portion of the shaft portion with respect to the guide hole are configured not to overlap when viewed in the axial direction.

  As a more specific aspect of the control valve of the present invention, the guide press-fitting hole has a large-diameter hole portion and a conical surface portion in order from one end side, and the cylindrical guide in order from the one end side It has a press-fitting part press-fitted into the diameter hole part, an intermediate part having a smaller diameter than the press-fitting part, and a shoulder part whose outer peripheral corner part is in line contact with the conical surface part over substantially the entire circumference.

  Further, the control valve for a variable displacement compressor according to the present invention is provided with a valve rod having an upper shaft portion, a valve body portion, and a lower shaft portion, and a valve port through which the valve body portion comes in contact with and separates from the valve stem. A valve body, an electromagnetic actuator for driving the valve stem in the valve opening / closing direction, and a pressure-sensitive responsive member for driving the valve rod in the valve opening / closing direction in response to a suction pressure of the compressor. The valve main body is provided with an upper guide hole into which the upper shaft portion of the valve stem is slidably inserted above the valve port, and a guide press-fitting hole having a larger diameter below the valve port. A cylindrical guide that forms a lower guide hole into which a lower shaft portion of the valve rod is slidably fitted is inserted and fixed at a lower portion of the guide press-fitting hole. A portion above the cylindrical guide in the case is a valve chamber, and the discharge pressure of the compressor is introduced into the valve chamber. The Pd hole is opened so that the press-fitting portion of the cylindrical guide into the guide press-fitting hole and the sliding portion of the lower shaft portion with respect to the lower guide hole do not overlap when viewed in the axial direction. It is characterized by having.

  In a more specific aspect of the control valve for a variable displacement compressor according to the present invention, the guide press-fitting hole has a large-diameter hole portion, a conical surface portion, and a small-diameter hole portion in order from the bottom, and the cylindrical guide Are, in order from the bottom, a press-fitted part that is press-fitted into the large-diameter hole part, an intermediate part having a smaller diameter than the press-fitted part, a shoulder part whose outer peripheral corner is substantially in line contact with the conical surface part over the entire circumference, and It has a small diameter part.

  In the control valve according to the present invention, since the sliding portion (Lb portion) of the shaft portion and the press-fitting portion (La portion) are not overlapped, the inner diameter of the cylindrical guide is reduced by press-fitting. There is no need to consider, and the sliding surface gap can be made narrower than that of the conventional example, particularly in the upper part of the cylindrical guide, so that the size range of foreign matter entering the gap is narrow. As a result, the gap is less likely to be clogged with foreign matter, and as a result, malfunction of the valve stem caused by the foreign matter can be prevented.

  In addition, a conical surface portion is provided in the guide press-fitting hole so that the outer peripheral corner portion of the shoulder portion of the cylindrical guide is substantially in line contact over the entire periphery, so that the outer peripheral corner portion of the shoulder portion is inserted into the conical surface portion at the time of press-fitting. Since the cylindrical guide is aligned by the conical surface portion by being brought into contact with, the processing accuracy of the guide press-fitting hole can be loosened, and the processing cost can be reduced.

Sectional drawing which shows the principal part of one Embodiment of the control valve for variable displacement compressors which concerns on this invention. (A) is an expanded sectional view which shows the principal part of the control valve of the prior art example shown by FIG. 3, (B) is a schematic diagram with which description of the subject of a prior art example is provided. Sectional drawing which shows an example of the conventional control valve for variable displacement compressors.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a main part of an embodiment of a control valve for a variable displacement compressor according to the present invention. The control valve 10 of the present embodiment is different from the control valve 5 shown in FIG. 3 described above only in the shape around the guide press-fitting hole 53, the cylindrical guide 52, the lower shaft portion 15e, and the lower guide hole 19B. Since the other parts are basically the same, the differences will be mainly described below.

  The valve main body 20 of the illustrated embodiment is provided with a guide press-fit hole 55 having a larger diameter below the valve port 22, and the lower shaft portion 15 e of the valve stem 15 slides below the guide press-fit hole 55. A cylindrical guide 54 that forms a lower guide hole 19B that is freely inserted is inserted and fixed by press-fitting.

  The guide press-fitting hole 55 has, in order from the bottom, a large-diameter hole portion 55a, a conical surface portion (annular tapered surface portion) 55b, and a small-diameter hole portion 55c slightly smaller in diameter than the large-diameter hole portion 55a.

  The cylindrical guide 54 includes, in order from the bottom, a relatively short press-fit portion 54a that is press-fitted into the large-diameter hole portion 55a, an intermediate portion 54b having a smaller diameter than the press-fit portion 54a, and an outer peripheral corner portion of the conical surface portion 55b. 54e has a shoulder portion 54c and a small-diameter portion 54d that are substantially in line contact with each other over the entire circumference.

  The figure shows a state where the valve stem 15 (lower shaft portion 15e) is in the lowest lowered position (fully opened state), and the lower end of the lower shaft portion 15e is equivalent to the lower end of the cylindrical guide 54 ( It is positioned above (as compared to the conventional example described above). Specifically, the lower end of the lower shaft portion 15e is positioned above the upper end of the press-fit portion 54a, and the sliding portion length Lb of the lower shaft portion 15e with respect to the lower guide hole 19B is set to be lower than that of the lower shaft portion 15e. The length is from the lower end to the upper end of the cylindrical guide 54.

  In other words, the sliding portion of the lower shaft portion 15e with respect to the lower guide hole 19B is not overlapped with the press-fit portion 54a when viewed in the axial direction (the La portion and the Lb portion overlap in the side view). Not to become)).

  Since the sliding portion (Lb portion) of the lower shaft portion 15e and the press-fit portion 54a (La portion) do not overlap in this way, the inner diameter of the cylindrical guide 54 is reduced by press-fitting. Therefore, the sliding surface gap α can be made narrower than that of the conventional example, particularly in the upper portion of the cylindrical guide 54, and therefore, foreign matter that enters the gap α can be reduced. As a result, the size range becomes narrower, and accordingly, the foreign matter M is less likely to be clogged in the gap α. As a result, the malfunction of the valve stem caused by the foreign matter can be prevented.

  In addition, when the length (La) of the press-fit portion 54a is short, the cylindrical guide 54 is easily tilted and assembled during press-fit, but as in the present embodiment, the outer peripheral corner portion 54e of the shoulder portion 55 of the cylindrical guide 54 is provided. Is provided with a conical surface portion 55b in the guide press-fitting hole 55, so that the outer peripheral corner portion 54e of the shoulder portion 54c is brought into contact with the conical surface portion 55b at the time of press-fitting. Since the guide 54 is aligned by the conical surface portion 55b, the processing accuracy of the guide press-fitting hole 55 can be relaxed, thereby reducing the processing cost.

  Note that the scope of application of the present invention is not limited to the control valve for a variable displacement compressor as in the above embodiment, and similarly applies to other control valves having a guide press-fitting hole and a cylindrical guide. Of course, it can be applied.

DESCRIPTION OF SYMBOLS 10 Variable displacement compressor control valve 15 Valve rod 15a Valve body 15c Upper shaft portion 15e Lower shaft portion 19A Upper guide hole 19B Lower guide hole 20 Valve body 21 Valve chamber 22 Valve port (valve seat portion)
25 Pd hole 26 Pc hole 26S Pc chamber 30 Electromagnetic actuator 40 Bellows body 54 Cylindrical guide 54a Press-fit portion 54b Intermediate portion 54c Shoulder portion 54d Small-diameter portion 54e Outer peripheral corner portion 55 Guide press-fit hole 55a Large-diameter portion 55b Conical surface portion 55c Small-diameter portion

Claims (4)

A valve stem having a valve body portion and a shaft portion, and a valve main body for slidably holding the valve stem,
The valve body is provided with a guide press-fitting hole, and a cylindrical guide that forms a guide hole into which the shaft portion of the valve rod is slidably fitted is inserted and fixed to one end of the guide press-fitting hole by press-fitting. Controlled valve,
A control valve characterized in that a press-fitting portion of the cylindrical guide into the guide press-fitting hole and a sliding portion of the shaft portion with respect to the guide hole do not overlap when viewed in the axial direction.   The guide press-fitting hole has a large-diameter hole part and a conical surface part in order from one end side, and the cylindrical guide is press-fitted into the large-diameter hole part in order from one end side, and the press-fitting part 2. The control valve according to claim 1, further comprising an intermediate portion having a smaller diameter and a shoulder portion having an outer peripheral corner portion substantially in line contact with the conical surface portion over the entire circumference. A valve stem having an upper shaft portion, a valve body portion, and a lower shaft portion, a valve body provided with a valve port for contacting and separating the valve body portion, and driving the valve rod in a valve opening / closing direction An electromagnetic actuator, and a pressure sensitive response member that drives the valve stem in the valve opening / closing direction in response to the suction pressure of the compressor,
The valve body is provided with an upper guide hole into which the upper shaft portion of the valve rod is slidably inserted above the valve port, and a guide press-fitting hole having a larger diameter below the valve port. A cylindrical guide is formed and press-fitted in a lower portion of the guide press-fitting hole to form a lower guide hole into which the lower shaft portion of the valve rod is slidably inserted. A control valve for a variable displacement compressor in which a portion above the cylindrical guide is a valve chamber, and a Pd hole for introducing a discharge pressure of the compressor is opened in the valve chamber,
A variable in which the press-fitting portion of the cylindrical guide into the guide press-fitting hole and the sliding portion of the lower shaft portion with respect to the lower guide hole do not overlap each other when viewed in the axial direction. Control valve for capacity compressor.   The guide press-fitting hole has a large-diameter hole portion, a conical surface portion, and a small-diameter hole portion in order from the bottom, and the cylindrical guide is a press-fit portion that is press-fitted into the large-diameter hole portion in order from the bottom. 4. The variable capacity compressor according to claim 3, further comprising an intermediate portion having a smaller diameter than a portion, a shoulder portion having an outer peripheral corner portion substantially in line contact with the conical surface portion, and a small diameter portion. Control valve for.

Images