Abstract:
A pipe connector is provided with a valve cartridge. The pipe connector can be modified so as to meet requirements for a variety of uses without changing the basic design of the connector body by simply replacing the valve cartridge with another valve cartridge having valve functions meeting a desired use. The pipe connector includes a tubular connector body  10  through which a fluid flows, and a valve cartridge  30  capable of being fitted in the connector body and of controlling the flow of the fluid.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pipe connector having a tubular body for carrying a fluid and a valve mechanism placed in the tubular body and, more particularly, to a pipe connector provided with a valve cartridge. 
     2. Description of the Related Art 
     Some pipe connectors are provided with a built-in valve mechanism. A pipe connector disclosed in JP-A 2002-168385 or JP-A 2003-028010 has a connector body and a valve mechanism built into the connector body. In this pipe connector, a valve seat having a valve opening is formed inside the connector body. A valve element is seated on the valve seat and a compression coil spring presses the valve element against the valve seat. 
     When the pressure of a fluid flowing through this pipe connector provided with the built-in valve mechanism increases, the fluid separates the valve element from the valve seat against the resilience of the compression coil spring to open the valve opening. The flow rate of the fluid flowing through the pipe connector is dependent on the spring characteristic of the compression coil spring. Therefore, this valve mechanism fails in the stable control of the flow rate when the spring characteristic changes with time. 
     A pipe connector provided with a built-in valve mechanism proposed in JP-A 2005-163836 to solve the foregoing problem is provided with a flow regulating orifice in addition to a valve opening opened and closed by a valve element pressed by a compression coil spring. The flow regulating orifice removes the influence of the characteristic of the compression coil spring on flow rate. 
     The valve mechanism built into the known pipe connector includes the valve seat formed in the connector body, and the valve element as essential elements. Therefore, the shape of the connector body necessarily needs to be changed to change the functional characteristics of the valve mechanism. Thus, the functional characteristics of the valve mechanism cannot be easily changed. 
     When the shape of the connector body is changed, the surface of the valve seat, the valve element and the compression coil spring need to be adjusted carefully and ascertained such that the valve element is lifted up by a predetermined pressure and a predetermined flow rate can be stably maintained. 
     Therefore, the functional valve parts need to be examined in combination with the connector body. Thus, the manufacture of pipe connectors provided with a valve mechanism for different uses and having different characteristics requires much time and labor, which increases the cost of the pipe connectors. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to solve problems in the prior art and to provide a pipe connector having a connector body and a replaceable valve cartridge having desired valve functions and combined with the connector body. The replaceable valve cartridge can be replaced with another one capable of exercising valve functions meeting intended use. The valve functions of the pipe connector can be changed by selectively combining a valve cartridge having desired valve functions with the same connector body. Thus, the same connector body can be used for forming a pipe connector having desired valve functions. 
     Another object of the present invention is to provide a pipe connector having a connector body and a valve cartridge whose valve functions can be tested before combining the valve cartridge with the connector body. 
     The present invention provides a pipe connector including: a tubular connector body through which a fluid flows; and a valve cartridge capable of being fitted in the connector body and of controlling the flow of the fluid; wherein the valve cartridge includes a valve element for opening and closing a flow passage, a coil spring for pressing the valve element, a case provided with a valve seat defining a valve opening and holding the valve element and the coil spring therein. 
     In the pipe connector according to the present invention, the case of the valve cartridge includes a first case provided with the valve seat, and a second case holding the coil spring therein. 
     In the pipe connector according to the present invention, the second case has an end part in which an end part of a pipe is fitted. 
     In the pipe connector according to the present invention, the valve element of the valve cartridge is provided with an orifice that allows the fluid to flow at a low flow rate. 
     In the pipe connector according to the present invention, the connector body is provided in its inside surface with a first interlocking par, and the case of the valve cartridge is provided in its outside surface with a second interlocking part capable of interlocking with the first interlocking part of the connector body. 
     In the pipe connector according to the present invention, the first interlocking part has a first annular groove and a first annular ridge, and the second interlocking part has a second annular ridge capable of engaging in the first annular groove and a second annular groove capable of engaging with the first annular ridge. 
     In the pipe connector according to the present invention, the case of the valve cartridge includes a first case provided with the valve seat, and a second case holding the coil spring therein, the connector body is provided in its inside surface with a first interlocking part, and the second case of the case is provided in its outside surface with a second interlocking part capable of interlocking with the first interlocking part. 
     In the pipe connector according to the present invention, the case of the valve cartridge is formed in a shape so that the case of the valve cartridge can be inserted into the connector body either in a forward direction or a backward direction. 
     The pipe connector of the present invention is a quick connector having the connector body and the valve cartridge fitted in the connector body. 
     The connector body of pipe connector of the present invention is provided at its opposite ends with connecting parts to be pressed in pipes, respectively. 
     In the pipe connector according to the present invention, the valve cartridge has valve functions independent of the type, shape and construction of the pipe connector. 
     A valve cartridge according to the present invention capable of being fitted in a tubular connector body through which a fluid flows and of controlling the flow of the fluid includes; a valve element for opening and closing f flow passage; a coil spring for pressing the valve element; and a cartridge case provided with a valve seat defining a valve opening, and holding the valve element and the coil spring therein. 
     According to the present invention, a pipe connector can be modified so as to meet requirements for a variety of uses without changing the basic design of the connector body by simply replacing the valve cartridge with another valve cartridge having valve functions meeting a desired use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal sectional view of a pipe connector in a first embodiment according to the present invention; 
         FIG. 2  is a longitudinal sectional view of an essential part of the pipe connector shown in  FIG. 1 ; 
         FIG. 3  is a longitudinal sectional view of a pipe connector in a second embodiment according to the present invention; 
         FIG. 4  is a longitudinal sectional view of an essential part of the pipe connector shown in  FIG. 3 ; 
         FIG. 5  is a perspective view of a pipe connector in a third embodiment according to the present invention; and 
         FIG. 6  is a longitudinal sectional view of the pipe connector shown in  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     Referring to  FIG. 1  showing a pipe connector in a first embodiment according to the present invention in a longitudinal sectional view, there are shown a connector body  10 , a pipe  12  to be connected to the connector body  10 , and a retainer  14  for retaining the pipe  12  in the connector body. 
     The pipe connector in the first embodiment is a quick connector. 
     The pipe  12  is made of a metal or a resin. The pipe  12  is provided on its outside surface with an annular ridge at a predetermined distance from its free end. 
     The retainer  14  is fitted through an inlet  20  in the connector body  10 . When an end part of the pipe  12  is inserted into the retainer  14 , the retainer holds the pipe  12  in the connector body  10 . Thus, the pipe  12  can be coupled with the connector body  10  by simply pressing the pipe  12  into the retainer  14 . 
     The retainer  14  is a plastic member having an inside diameter approximately equal to the outside diameter of the pipe  12 . The retainer  14  is integrally provided with locking fingers  18   a  and  18   b . The locking fingers  18   a  and  18   b  engage with the annular ridge  15  of the pipe  12  when the pipe  12  is inserted into the retainer  14 . 
     The connector body  10  is a female coupler into which the pipe  12  is inserted. The connector body  10  is integrally provided with a press-in connecting part  18  to be pressed in a resin pipe. The connector body  10  defines an axial flow passage  21 . The connector body  10  has four cylindrical parts respectively having different inside diameters, namely, a first cylindrical part  22 , a second cylindrical part  25 , a third cylindrical part  26  and the corrugated press-in connecting part  18 . O rings  23  are fitted in the first cylindrical part  20  having a big diameter and is retained in place by an O ring retainer  24 . The second cylindrical part  25  receives an end part of the pipe  12 . The third cylindrical part  26  holds a valve cartridge  30 . 
     As shown in  FIG. 1 , the valve cartridge  30  capable of controlling flow rate is fitted in the connector body  10 . The valve cartridge  30  can be removed from the connector body  10 . The valve cartridge  30  exercises valve functions independent of the shape and construction of the connector body  10 . 
     Referring to  FIG. 2 , the valve cartridge  30  includes a case  31 , a valve element  32  and a coil spring  33 . The case  31  is divided into two cylindrical cases, namely, a first case  34  and a second case  35 . The first case  34  is provided with a valve seat  36  having a contact surface  37  and defining a valve opening. 
     The valve element  32  is seated on the valve seat  36  in close contact with the contact surface  37 . The valve element  32  is held on a head end of a cylindrical member  38 . An annular groove  39  of a predetermined depth is formed in a tail end of the cylindrical member  38 . A head end part of a coil spring  33  is received in the annular groove  39  of the cylindrical member  38 . The second case  35  is provided with a spring seat  40 . The tail end of the coil spring  33  is seated on the spring seat  40 . As shown in  FIG. 2 , the coil spring  33  is compressed between the cylindrical member  38  and the spring seat  40  to press the valve element  32  resiliently against the contact surface  37  of the valve seat  37 . 
     In a state shown in  FIG. 2 , the flow passage  21  is closed. However, since the valve element  32  is provided with an orifice  41 , it allows the fluid to flow at a predetermined flow rate through the valve element  32 . 
     As shown in  FIG. 2 , valve guides  42  formed integrally with the valve element  32  extends axially through the valve opening defined by the valve seat  36 . The valve guide  42  ensures the smooth movement of the valve  32  and maintains the valve element  32  is a correct position. 
     A fixing mechanism for fixedly holding the valve cartridge  30  in the connector body  10  will be described. Referring to  FIG. 2 , the second cylindrical part is provided in its inside surface with an annular groove  43  and a shoulder  44 . The second case  35  of the valve cartridge  30  is provided on its outside surface with an annular ridge  46  that engages in the annular groove  43 , and a flange  45  that engages with the shoulder  44 . The valve seat  36  is formed in an end wall  47  of the first case  34  of the valve cartridge  30 . The end wall  47  of the first case  34  comes into contact with a shoulder  22   a  formed in the second cylindrical part  22  of the connector body  10  to position the valve cartridge  30  in the connector body  10 . Thus, the valve cartridge  30  can be positioned and held in the connector body  10  simply by pressing the valve cartridge  30  into the connector body  10 . 
     The valve cartridge  30  is made by assembling the case  31 , the valve element  32  and the coil spring  33 . Thus, the valve cartridge can be assembled and tested independently of the connector body  10 . 
     The case  31  is divided into the cylindrical first case  34  and the cylindrical second case  35 . The valve seat  36 , which exercises important valve functions in combination with the valve element  32 , is formed in the first case  34 . The second case  35 , which exercises mechanical functions, is used for compressing the coil spring  33 . Thus, the first case  34  and the second case  35  can be individually manufactured so as to meet characteristics required of the first case  34  and the second case  35 . 
     The valve cartridge  30  is inserted into the connector body  10 . The annular ridge  46  formed on the outside surface of the second case  35  of the valve cartridge  30  engages in the annular groove  43  formed in the inside surface of the second cylindrical part of the connector body  10 , and the flange  45  of the second case  35  of the valve cartridge  30  engages with the shoulder  44  formed in the inside surface of the second cylindrical part of the connector body  10  when the valve cartridge  30  is pressed into the connector body  10 . Thus the valve cartridge  30  can be incorporated into the connector body  10  simply be pressing the valve cartridge  30  into the connector body  10 . The case  31  is divided into the cylindrical first case  34  and the cylindrical second case  35 . The annular ridge  46  that engages in the annular groove  43  and the flange  45  that engages with the shoulder  44  are formed in the second case  35  to use the second case  35  mainly for dynamically fixing the valve cartridge  30  in the connector body  30 . Thus, the first case  34  provided with the valve seat  36  does not need to have a function for dynamically fixing the valve cartridge  30  in the connector body  10 . 
     The pipe connector with a built-in valve includes the connector body  10  and the valve cartridge  30 . Pipe connectors having different desired valve functions can be formed by combining valve cartridges having different desired valve functions with connector bodies of the same design, respectively. Thus, the design of the connector body  10  does not need to be changed in providing a pipe connector with a built-in valve having desired valve functions. 
     Operations and effects of the pipe connector in the first embodiment will be described. The following valve functions are imparted to the pipe connector in the first embodiment by incorporating the valve cartridge  30  into the connector body  10 . Since the valve element  32  is provided with the orifice  41 , the fluid is allowed to flow at a low flow rate through the pipe connector in a state where the valve element  32  is seated on the valve seat  36  by the resilience of the coil spring  33 . 
     When the pressure of the fluid flowing through the flow passage  21  rises, the pressure of the fluid tries to lift the valve element  32  from the valve seat  36  against the resilience of the coil spring  33 . Upon the increase of the pressure of the fluid beyond a predetermined pressure, the valve element  32  is separated from the contact surface  37  of the valve seat  36  and the fluid starts flowing through the gap between the valve element  32  and the contact surface  37  of the valve seat  36  at a flow rate higher than that of the fluid flowing through the orifice  41 . 
     The valve cartridge  30  of the pipe connector in the first embodiment has a valve function for adjusting the flow rate of the fluid to either of two levels, namely, the low flow rate and the high flow rate. The valve functions of the valve cartridge  30  are not dependent at all on the shape and construction of the connector body  10 . Therefore, the valve cartridge  30  has the following advantages. 
     Many functionally different valve cartridges  30  respectively provided with coil springs respectively having different spring constants and orifices  41  respectively having different diameters and respectively conforming to required control characteristics are prepared for use in combination with a connector body  10 . One valve cartridge  30  having a desired valve function among the functionally different valve cartridges  30  is used in combination with the connector body  10  to provide a pipe connector having a desired working characteristic. 
     Pipe connectors having different shapes can be easily made by combining the valve cartridge  30  with connector bodies  10  respectively having different shapes. The pipe connector in the first embodiment is formed by combining the straight connector body  10  and the valve cartridge  30 . Pipe connectors respectively having a valve function and various shapes can be made by combining the valve cartridge  30  with, for example, elbows and tees, namely, pipe fittings. 
     The performance of the valve cartridge  30  can be tested before combining the valve cartridge  30  with the connector body  10  and hence the pipe connector provided with the valve cartridge does not need to be tested. Consequently, fraction defective can be reduced. 
     Second Embodiment 
     A pipe connector in a second embodiment according to the present invention will be described with reference to  FIGS. 3 and 4 . 
     The pipe connector in the second embodiment, similarly to the pipe connector in the first embodiment, can withstand high pressures. The pipe connector in the second embodiment is a large pipe connector provided with a large valve cartridge. Since the basic components of the pipe connector in the second embodiment are the same as those of the pipe connector in the first embodiment, the same components are designated by the same reference characters and the description thereof will be omitted. 
     A pipe holding part  48  is formed integrally with a second case  35  of a case of the valve cartridge. An end part of a pipe  12  is received in the pipe holding part  48  of the second case  35 . In the second embodiment, the pipe holding part  48  for receiving the end part of the pipe  12 , which is formed normally in a connector body  10 , is formed integrally with the second case  35  of the valve cartridge  30 . Therefore, the dimensional augmentation of the functional parts of the valve cartridge  30  can be absorbed by the second case  35 , which increases the degree of freedom of design of the functional parts of the valve cartridge  30 . Since the valve cartridge  30  undertakes some of the functions of the pipe connector, details of the pipe connector can be easily adjusted. 
     Third Embodiment 
     A pipe connector in a third embodiment according to the present invention will be described with reference to  FIGS. 5 and 6 . 
     The pipe connector in the third embodiment is formed by combining the valve cartridge  30  of the first embodiment into a pipe connector shown in  FIGS. 5 and 6 . Therefore the description of the valve cartridge  30  will be omitted. 
     A connector body  50  included in the pipe connector has press-in connecting parts  51   a  and  51   b  extending in opposite directions from the opposite ends of the connector body  50 , respectively. The connecting parts  51   a  and  51   b  are pressed into resin pipes, respectively. The connecting parts  51   a  and  51   b  are provided with stopping ridges  53  for preventing the separation of the resin pipes connected to the connecting parts  51   a  and  51   b . O rings are engaged in annular grooves  54  formed in the connecting parts  51   a  and  51   b.    
     A valve positioning ring  55  protrudes from the inside surface of a connector body  50 . An annular groove  43  and a shoulder  44  are formed in the inside surface of the connector body  50 . A second case  35  of the valve cartridge  30  is provided on its outside surface with an annular ridge  46  that engages in the annular groove  43 , and a flange  45  that engages with the shoulder  44 . A fixing structure that fixes the valve cartridge  30  in a connector body  50  is similar to that of the first embodiment. 
     The valve cartridge  30  can be incorporated not only into the connector bodies  10  to form the pipe connectors in the first and the second embodiment, namely, quick connectors, but also into the connector body  50  having the connecting parts  51   a  and  51   b  to be pressed in the resin pipes, respectively, to form the pipe connector in the third embodiment. The pipe connector in the third embodiment is formed by combining the straight connector body  50  and the valve cartridge  30 . Pipe connectors respectively having a valve function and various shapes can be made by combining the valve cartridge  30  with, for example, elbows and tees, namely, pipe fittings. 
     Although the preferred embodiments of the present invention have been described, the present invention is not limited thereto in its practical application. For example, the case of the valve cartridge may be formed in a shape such that makes it possible for the valve cartridge to be inserted into the connector body either in a forward direction or in a backward direction. Although the valve cartridge  30  is fitted in the connector body  10  with the valve element  32  disposed on the left side in the first embodiment shown in  FIG. 2 , the annular groove  43  and the shoulder  44  of the second cylindrical part  22  of the connector body  10  and the annular ridge  46  formed on the outside surface of the second case  35  of the valve cartridge  30  and the flange  45  of the second case  35  may be shaped and positioned such that the valve cartridge  30  can be fitted in the connector body  10  with the valve element  32  disposed on the right side as viewed in  FIG. 2 .