Patent Publication Number: US-8973891-B2

Title: Air bypass valve device

Description:
TECHNICAL FIELD 
     The present invention relates to an air bypass valve device directly installed to a turbo charger, and particularly relates to the fitting of a case and a valve assembly. 
     BACKGROUND ART 
     Conventionally, a snap-fit system is employed for the fitting of a case and a valve assembly in this kind of air bypass valve device, as disclosed in Patent Document 1 and Patent Document 2. The fitting of the case and the valve assembly (assy) is not a matter which is directly relevant to an operating principle; however, if the fitting is not prepared, a spring, the case, and the valve assembly in which a holder, a diaphragm, and a valve are integrally assembled are put in an individual state as three parts until an installment thereof to a compressor housing of a turbo charger. For this reason, there is a problem such that the working efficiency for mounting the parts to the compressor housing is very bad. 
     In order to solve the above-described problem, a snap-fit unit is prepared for the valve assembly; when the valve assembly is fitted in and assembled to the case in a state where the spring is compressed and stored by a flange of the snap-fit unit, the three parts put in an individual state can be transported and handled as one part, to thereby enhance the working efficiency for mounting the parts to the compressor housing of the turbo charger. 
     However, a length of the snap-fit unit needs to be increased to obtain a sufficient flexure amount thereof depending on the material property (physical property) of parts to be used; as a result, it is difficult to decrease the total height of the air-bypass valve device, namely, to obtain a thinner one. 
     There is no problem when a flexible resin material such as PA66 can be employed for the snap-fit unit; however, in the case that the material is changed (the resin material is changed to PPS and so on) for the purpose of increasing the heat resistance, a structure with the same height could not be achieved due to the poor resistance to flexure. For this reason, the snap-fit unit needs to be elongated to obtain a sufficient flexure amount thereof; however, an elongated snap-fit unit interferes with a nipple as a pressure port that is prepared in the case, which poses a problem such that an operating stroke amount of a product is reduced. 
     In order to solve this problem, it can be considered to move the nipple in an upper direction; however, in order to move the nipple in the upper direction, the size of the case needs to be increased, which leads to an increase of the total height of the air bypass valve device, resulting in the degradation of the mountability thereof on vehicles. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     Patent Document 1: Japanese Patent Application Laid-Open No. H2-305324 
     Patent Document 2: Japanese Examined Patent Publication No. H8-006601 
     SUMMARY OF THE INVENTION 
     The present invention is made to solve the above-described problem, and an object of the invention is to provide an air bypass valve device that can maintain the total height of a product at a constant height without being affected by material properties (physical properties) thereof, and has superior mountability thereof on vehicles. 
     In an air bypass valve device of the invention, a tenon is provided to one of a valve assembly and a case, and a tenon groove is provided to the other, and after insertion of the tenon into the tenon groove, the valve assembly and the case are relatively rotated to be united, to thereby form a tenon insertion structure. 
     According to the air bypass valve device of the invention, since the case and the valve assembly are united by the tenon insertion structure, the total height of a product can be maintained at a constant height without being affected by material properties (physical properties) thereof. Further, since the case and the valve assembly can be handled and transported as one part, no fall-out of the valve assembly occurs during transport, and the working efficiency of mounting the device on the compressor housing of the turbo charger is enhanced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a transverse cross-sectional view illustrating a state that an air bypass valve device is directly fitted to a compressor housing of a turbo charger according to Embodiment 1 of the present invention. 
         FIG. 2  is an explanatory view illustrating a tenon insertion structure of a case and a valve according to Embodiment 1 of the invention;  FIGS. 2(   a )- 1 ,  2 ( a )- 2 ,  2 ( a )- 3  are sectional views and a bottom view of a tenon groove formation part of the case, respectively,  FIGS. 2(   b )- 1 ,  2 ( b )- 2  are a plan view and a side view of a tenon formation part of the valve, respectively, and  FIGS. 2(   c )- 1 ,  2 ( c )- 2  are sectional views illustrating a tenon inserting state of the tenon groove formation part of the case and the tenon formation part of the valve, respectively. 
         FIG. 3  is an explanatory view illustrating a tenon insertion structure of a case and a valve according to Embodiment 2 of the invention;  FIGS. 3(   a )- 1 ,  3 ( a )- 2 ,  3 ( a )- 3  are sectional views and a bottom view of a tenon groove formation part of the case, respectively,  FIGS. 3(   b )- 1 ,  3 ( b )- 2  are a plan view and a side view of a tenon formation part of the valve, respectively, and  FIGS. 3(   c )- 1 ,  3 ( c )- 2  are sectional views illustrating a tenon inserting state of the tenon groove formation part of the case and the tenon formation part of the valve, respectively. 
         FIG. 4  is an explanatory view illustrating a tenon insertion structure of a case and a valve according to Embodiment 3 of the invention;  FIGS. 4(   a )- 1 ,  4 ( a )- 2 ,  4 ( a )- 3  are sectional views and a bottom view of a tenon groove formation part of the case, respectively,  FIGS. 4(   b )- 1 ,  4 ( b )- 2  are a plan view and a side view of a tenon formation part of the valve, respectively, and  FIGS. 4(   c )- 1 ,  4 ( c )- 2  are sectional views illustrating a tenon inserting state of the tenon groove formation part of the case and the tenon formation part of the valve, respectively. 
         FIG. 5  is an explanatory view illustrating a tenon insertion structure of a case and a valve according to Embodiment 4 of the invention, wherein  FIGS. 5(   a )- 1 ,  5 ( a )- 2 ,  5 ( a )- 3  are sectional views and a bottom view of a tenon groove formation part of the case, respectively,  FIGS. 5(   b )- 1 ,  5 ( b )- 2  are a plan view and a side view of a tenon formation part of the valve, and  FIGS. 5(   c )- 1 ,  5 ( c )- 2  are sectional views illustrating a tenon inserting state of the tenon groove formation part of the case and the ten formation part of the valve, respectively. 
         FIG. 6  is a transverse cross-sectional view illustrating an air bypass valve device according to Embodiment 5 of the invention. 
         FIG. 7  is an explanatory view illustrating a tenon insertion structure of a case and a holder according to Embodiment 5 of the invention;  FIGS. 7(   a )- 1 ,  7 ( a )- 2 ,  7 ( a )- 3  are a front view, a bottom view, and a side view of a tenon formation part, respectively,  FIGS. 7(   b )- 1 ,  7 ( b )- 2 ,  7 ( b )- 3 ,  7 ( b )- 4  are a plan view, a sectional view, a bottom view and a sectional view of a tenon groove formation part, and  FIGS. 7(   c )- 1 ,  7 ( c )- 2 ,  7 ( c )- 3  are a plan view, a sectional view, a bottom view, and a sectional view of a tenon inserting state of the tenon formation part of the case and the tenon groove formation part of the valve, respectively. 
         FIG. 8  is an explanatory view illustrating a tenon insertion structure of a case and a holder according to Embodiment 6 of the invention;  FIGS. 8(   a )- 1 ,  8 ( a )- 2 ,  8 ( a )- 3  are a front view, a bottom view, and a side view of a tenon formation part, respectively,  FIGS. 8(   b )- 1 ,  8 ( b )- 2 ,  8 ( b )- 3 ,  8 ( b )- 4  are a plan view, a sectional view, a bottom view, and a sectional view of a tenon groove formation part, respectively, and  FIGS. 8(   c )- 1 ,  8 ( c )- 2 ,  8 ( c )- 3  are a plan view, a sectional view, and a bottom view of a tenon inserting state of the tenon formation part of the case and the tenon groove formation part of the valve, respectively. 
         FIG. 9  is an explanatory view illustrating a tenon insertion structure of a case and a holder according to Embodiment 7 of the invention;  FIGS. 9(   a )- 1 ,  9 ( a )- 2 ,  9 ( a )- 3  are a front view, a bottom view, and a side view of a tenon formation part of the case, respectively, and  FIGS. 9(   b )- 1 ,  9 ( b )- 2 ,  9 ( b )- 3 ,  9 ( b )- 4  are a plan view, a sectional view, a bottom view, a sectional view of a tenon groove formation part of the holder, respectively, and  FIGS. 9(   c )- 1 ,  9 ( c )- 2 ,  9 ( c )- 3  are a plan view, a sectional view, and a bottom view showing a tenon inserting state of the tenon formation part of the case and the tenon groove formation part of the valve, respectively. 
         FIG. 10  is a transverse cross-sectional view illustrating an air bypass valve device according to Embodiment 8 of the invention. 
         FIG. 11  is a transverse cross-sectional view illustrating an air bypass valve device according to Embodiment 9 of the invention. 
         FIG. 12  is an exploded perspective view of an air bypass valve device according to Embodiment 9. 
         FIG. 13  is an explanatory view illustrating a tenon insertion structure of a case and a holder according to Embodiment 9 of the invention;  FIGS. 13(   a )- 1 ,  13 ( a )- 2 ,  13 ( a )- 3  are a front view, a bottom view, and a side view of a tenon formation part of the case, respectively,  FIGS. 13(   b )- 1 ,  13 ( b )- 2 ,  13 ( b )- 3 ,  13 ( b )- 4  are a plan view, a sectional view, a bottom view, and a sectional view of a tenon groove formation part of the holder, respectively, and  FIGS. 13(   c )- 1 ,  13 ( c )- 2 ,  13 ( c )- 3  are a plan view, a sectional view, and a bottom view of a tenon inserting state of the valve and the tenon groove formation part, respectively. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     In the following, embodiments of the present invention will be described with reference to the accompanying drawings. 
     Embodiment 1 
     An air bypass valve device  1  according to Embodiment 1 of the invention illustrated in  FIG. 1  is directly installed to a compressor housing  2  of a turbo charger by a fastening unit (not depicted). The air bypass valve device  1  is composed of a case  3 , a spring  4 , and a valve assembly (assy)  5 . 
     The case  3  has a bottomed cylindrical part  3   a  interiorly, and tenon grooves  3   b  are formed on the bottom surface thereof as illustrated in  FIGS. 2(   a )- 1 ,  2 ( a )- 2 ,  2 ( a )- 3 . Further, a nipple  10  as a pressure port A is attached to the upper surface of the case  3  such that an inner through-hole of the nipple is aligned with a through-hole  3   c  of the case to communicate with the through-hole  3   c . Further, a cover  9  is attached to an upper end opening of the bottomed cylindrical part  3   a  to be closed. It is noted that a negative pressure acts on the pressure port A. 
     In the compressor housing  2 , a pressure port B connected to an intake side of an engine (not shown) and a pressure port C connected to an air cleaner (not shown) are formed, and the valve assembly  5  is attached to the upper end of the pressure port C. 
     The valve assembly  5  is composed of a valve  6 , a diaphragm  7 , and a holder  8 . A rubber seal  6   a  is attached to the central part on the lower surface of the valve  6 , and the central part of the valve  6  is subjected to drawing to be convex inwardly. Then, a columnar body  6   c  is formed at the center of a drawing part  6   b  thereof, and as illustrated in  FIGS. 2(   b )- 1 ,  2 ( b )- 2 , tenons  6   d  are provided symmetrical about an axis on the peripheral surface at the upper end of the columnar body  6   c . Then, the circumferential area of the valve  6  is bent upwardly. 
     The diaphragm  7  has a hole  7   a  to be fit in by the central convex part  6   b  of the valve  6  at the central part on the bottom surface, the circumferential area thereof is expanded in a trumpet shape along an upwardly bent part  6   e  of the valve  6 , and a convex part  7   b  is formed on the peripheral edge expanded in a trumpet shape to be engaged with a concave part  3   d  on the bottom surface of the case  3 . 
     The holder  8  is formed in a cup-shape in cross-section, a cylindrical part  8   a  is formed at the central part thereof to accommodate the insertion of the bottomed cylindrical part  3   a  of the case  3 , and a convex part  8   b  for positioning the spring  4  is formed at the base of the cylindrical part  8   a . Further, a concave part  8   c  is formed on the lower surface thereof to be engaged with a convex part  7   c  formed on the periphery of the hole  7   a  of the diaphragm  7 . 
     With the above arrangement of Embodiment 1, first, a convex part  6   a - 1  of the rubber seal  6   a  is integrally assembled into a hole  6   f  of the valve  6  by pressure compression molding and baking, then a central convex part  6   b  of the valve  6  is inserted and assembled into a hole  7   a  of the diaphragm  7 , and the holder  8  is overlapped on the diaphragm  7 , thus uniting three components of the valve  6 , the diaphragm  7 , and the holder  8  by means of bonding, welding and so on, to thereby form the valve assembly  5 . 
     Then, as illustrated in  FIGS. 2(   b )- 1 ,  2 ( b )- 2 , the directions of the tenons  6   d  formed on the columnar body  6   c  of the valve  6  that is a component of the valve assembly  5  are aligned with the tenon grooves  3   b  of the case  3  illustrated in  FIGS. 2(   a )- 1 ,  2 ( a )- 2 ,  2 ( a )- 3 , and the tenons are inserted into the bottomed cylindrical part  3   a  while the spring  4  interposed between the case  3  and the holder  8  is compressed. Then, the columnar body  6   c  and the bottomed cylindrical part  3   a  are relatively rotated by approximately 45 degrees to be set in the state of  FIGS. 2(   c )- 1 ,  2 ( c )- 2 , and the tenons  6   d  are pressed on the bottom surface of the bottomed cylindrical part  3   a  by an elastic restoring force of the spring  4 , to thereby unite the case  3  and the valve assembly  5 . In the thus united state, the case  3  is mounted on an attaching place of the compressor housing  2 , and attached and fixed thereto by a screw (not illustrated) through a threaded hole  3   e of the case  3 . 
     As described above, according to Embodiment 1, since the case  3  and the valve  6  are assembled by a tenon insertion structure, the flexibility of the columnar body  6   c  does not need to be taken into consideration, and thereby an elongated one of the body is unnecessary. As a result, the total height of the air bypass valve device  1  can be decreased to form a thinner one of the valve. Further, the case  3  and the valve assembly  5  can be transported as one part, which facilitates the handling, and fall-out or disengagement of the valve assembly  5  during transport can be prevented. 
     Embodiment 2 
     As illustrated in  FIG. 3 , in Embodiment 2, unpenetrated tenon fixing holes  3   f  are provided at positions orthogonal to tenon grooves  3   b  formed in a bottomed cylindrical part  3   a  of a case  3 ; the other arrangement is the same as that of Embodiment 1 illustrated in  FIGS. 1 ,  2 , and thereby the same signs and numerals are assigned to the same parts, and redundant explanations thereof will be omitted. 
     According to Embodiment 2, as illustrated in  FIGS. 3(   b )- 1 ,  3 ( b )- 2 , the directions of tenons  6   d  formed on a columnar body  6   c  of a valve  6  that is a component of a valve assembly  5  are aligned with the tenon grooves  3   b  of the case  3  illustrated in  FIGS. 3(   a )- 1 ,  3 ( a )- 2 ,  3 ( a )- 3 , and the tenons are inserted into the bottomed cylindrical part  3   a  while a spring  4  interposed between the case  3  and a holder  8  is compressed. Then, the columnar body  6   c  and the bottomed cylindrical part  3   a  are relatively rotated by approximately 45 degrees to be set in the state of  FIGS. 3(   c )- 1 ,  3 ( c )- 2 , then the tenons  6   d  are engaged with the tenon fixing holes  3   f , and thereafter the tenons  6   d  are pressed into the tenon fixing holes  3   f  by an elastic restoring force of the spring  4 , to thereby regulate a relative rotation between the columnar body  6   c  and the bottomed cylindrical part  3   a . As a result, the following situation can be securely prevented: the columnar body  6   c  and the bottomed cylindrical part  3   a  are relatively rotated by vibration and so on during transport, and then the tenons  6   d  and the tenon grooves  3   b  are conformed with each other, so that the valve assembly  5  is fallen out from the case  3 . 
     Embodiment 3 
     As illustrated in  FIG. 4 , in Embodiment 3, tenon grooves  3   b  formed on the bottom surface of a bottomed cylindrical part  3   a  of a case  3  are provided with openings  3   b - 1  which are largely opened in a trumpet shape outwardly; the other arrangement is the same as that of Embodiment 2 illustrated in  FIG. 3 , and thereby the same signs and numerals are assigned to the same parts, and redundant explanations thereof will be omitted. 
     According to Embodiment 3, as illustrated in  FIGS. 4(   b )- 1 ,  4 ( b )- 2 , the directions of tenons  6   d  formed on a columnar body  6   c  of a valve  6  that is a component of the valve assembly  5  are aligned with the tenon grooves  3   b  of the case  3  illustrated in  FIGS. 4(   a )- 1 ,  4 ( a )- 2 ,  4 ( a )- 3 , and the tenons are inserted into the bottomed cylindrical part  3   a  while a spring  4  interposed between the case  3  and a holder  8  is compressed; in this instance, since the tenon grooves  3   b  are provided with the openings  3   b - 1  largely opened in a trumpet shape outwardly, the insertion of the tenons  6   d  into the tenon grooves  3   b  is enhanced, so that the tenon insertion can be easily carried out. Then, after the tenon insertion, the columnar body  6   c  and the bottomed cylindrical part  3   a  are relatively rotated by approximately 45 degrees to be set in the state of  FIGS. 4(   c )- 1 ,  4 ( c )- 2 , then the tenons  6   d  are engaged with the tenon fixing holes  3   f , and thereafter the tenons  6   d  are pressed into the tenon fixing holes  3   f  by the elastic restoring force of the spring  4 , to thereby regulate a relative rotation between the columnar body  6   c  and the bottomed cylindrical part  3   a . As a result, the following situation can be securely prevented: the columnar body  6   c  and the bottomed cylindrical part  3   a  are relatively rotated by vibration and so on during transport, and then the tenons  6   d  and the tenon grooves  3   b  are conformed with each other, so that the valve assembly  5  is fallen out from the case  3 . 
     Embodiment 4 
     As illustrated in  FIG. 5 , in Embodiment 4, circumferential tenon fixing grooves  3   g  are provided widely in a traveling direction of tenons at positions orthogonal to tenon grooves  3   b  formed on a bottomed cylindrical part  3   a  of a case  3 ; the other arrangement is the same as that of Embodiment 3 illustrated in  FIG. 3 , and thereby the same signs and numerals are assigned to the same parts, and redundant explanations thereof will be omitted. 
     According to Embodiment 4, as illustrated in  FIGS. 5(   b )- 1 ,  5 ( b )- 2 , the directions of tenons  6   d  formed on a columnar body  6   c  of a valve  6  that is a component of a valve assembly  5  are aligned with the tenon grooves  3   b  of the case  3  illustrated in  FIGS. 5(   a )- 1 ,  5 ( a )- 2 ,  5 ( a )- 3 , and the tenons are inserted into the bottomed cylindrical part  3   a  while a spring  4  interposed between the case  3  and a holder  8  is compressed. Then, after the tenon insertion, when the columnar body  6   c  and the bottomed cylindrical part  3   a  are relatively rotated, the tenons  6   d  are engaged with the circumferential tenon fixing grooves  3   g  as illustrated in  FIGS. 5(   c )- 1 ,  5 ( c )- 2 . In this instance, since the tenon fixing grooves  3   g  are formed circumferentially, the insertion/engagement of the tenons  6   d  into/with the tenon fixing grooves  3   g  are enhanced. Then, after the engagement, the tenons  6   d  are pressed into the tenon fixing holes  3   f  by the elastic restoring force of the spring  4 , which are regulated owing to a relative rotation between the columnar body  6   c  and the bottomed cylindrical part  3   a  within the tenon fixing grooves  3   g . As a result, the following situation can be securely prevented: the columnar body  6   c  and the bottomed cylindrical part  3   a  are relatively rotated by vibration and so on during transport, and then the tenons  6   d  and the tenon grooves  3   b  are conformed with each other, so that the valve assembly  5  is fallen out from the case  3 . 
     Embodiment 5 
     An air bypass valve device  1  according to Embodiment 5 of the invention illustrated in  FIG. 6  is composed of a case  3 , a spring  4 , and a valve assembly  5 . 
     The case  3  has a columnar body  3   h  interiorly, and as illustrated in  FIGS. 7(   a )- 1 ,  7 ( a )- 2 ,  7 ( a )- 3 , tenons  3   i  are provided symmetrical about an axis on the peripheral surface at the lower end of a columnar body  3   h . Further, a nipple  10  as a pressure port A is attached to the upper surface of the case  3  such that an inner through-hole of the nipple is aligned with a through-hole  3   c  of the case to communicate with the through-hole. 
     The valve assembly  5  is composed of a valve  6 , a diaphragm  7 , and a holder  8 . A reinforcing plate  6   a  is attached to the central part on the lower surface of the valve  6 , and the central part of the valve  6  is subjected to drawing to be convex inwardly. Then, the peripheral part of the valve  6  is bent upwardly. 
     The diaphragm  7  has a hole  7   a  to be fit in by the central convex part  6   b  of the valve  6 , the peripheral part thereof is expanded in a trumpet shape along an upwardly bent part  6   e  of the valve  6 , and a convex part  7   b  is formed on the peripheral edge of the part expanded in a trumpet shape to be engaged with a concave part  3   d  on the bottom surface of the case  3 . 
     The holder  8  is formed in a cup-shape in cross-section, a cylindrical part  8   f  is formed at the central part thereof, and tenon grooves  8   e  opened to the upper end face thereof are provided symmetrical about an axis inside the cylindrical part, and tenon sliding grooves  8   g  are formed in parallel to the tenon grooves  8   e  to communicate with the tenon grooves at the lower end thereof, but are unpenetrated at the upper end thereof. Then, a convex part  8   b  for positioning the spring  4  is formed at the base of the cylindrical part  8   f . Further, a concave part  8   c  is formed on the lower surface thereof to be engaged with a convex part  7   c  formed on the periphery of a hole  7   a  of the diaphragm  7 . 
     With the above arrangement of Embodiment 5, first, a convex part  6   a - 1  of the rubber seal  6   a  is inserted into a hole  6   f  of the valve  6  to be integrally assembled, then the central convex part  6   b  of the valve  6  is engaged with the hole  7   a  to assemble the diaphragm  7 , and the holder  8  is overlapped on the diaphragm  7 , so that three components of the valve  6 , the diaphragm  7 , and the holder  8  are united by means of bonding, welding and so on, to thereby form the valve assembly  5 . 
     Then, as illustrated in  FIGS. 7(   b )- 1 ,  7 ( b )- 2 ,  7 ( b )- 3 ,  7 ( b )- 4 , the directions of the tenon grooves  8   e  of the cylindrical part  8   f  of the holder  8  constituting the valve assembly  5  are aligned with the tenons  3   i  of the case  3  illustrated in  FIGS. 7(   a )- 1 ,  7 ( a )- 2 ,  7 ( a )- 3 , and the tenons are inserted thereinto while the spring  4  interposed between the case  3  and the holder  8  is compressed. Then, after the tenons  3   i  is inserted thereinto to reach the terminal ends of the tenon grooves  8   e , the case  3  and the valve assembly  5  are relatively rotated by approximately 45 degrees, so that the tenons  3   i  are matched with the tenon sliding grooves  8   g  of which are unpenetrated at the upper end thereof; then, the tenons  3   i  are traveled inside the tenon sliding grooves  8   g  by the elastic restoring force of the spring  4  to be pressed on the inner surfaces of the unpenetrated upper ends of the tenon sliding grooves  8   g  as illustrated in  FIGS. 7(   c )- 1 ,  7 ( c )- 2 ,  7 ( c )- 3 , to thereby unite the case  3  and the valve assembly  5 . In the thus united state, the case  3  is mounted on an attaching place of the compressor housing  2  (see  FIG. 1) , and attached and fixed thereto by a fastening means such as screwing, bonding, and welding. 
     As described above, according to Embodiment 1, since the case  3  and the valve  6  are assembled by a tenon insertion structure, the flexibility of the columnar body  3   h  does not need to be taken into consideration, and thereby an elongated one of the body is unnecessary. As a result, the total height of the air bypass valve device  1  can be decreased to form a thinner one, and thereby mountability thereof on vehicles is enhanced. Further, fall-out of the valve assembly  5  during transport can be prevented. 
     Embodiment 6 
     As illustrated in  FIG. 8 , in Embodiment 6, a rotating direction regulating side wall  8   h  is provided on one side of the terminal ends of tenon grooves  8   e  which are formed inside a cylindrical part  8   f  of a holder  8 , and a communication groove  8   i  is provided only in one direction to communicate with the tenon sliding groove  8   g  unpenetrated at the upper end thereof; the other arrangement is the same as that of Embodiment 5 illustrated in  FIG. 6 , and thereby the same signs and numerals are assigned to the same parts, and redundant explanations thereof will be omitted. 
     According to Embodiment 6, as illustrated in  FIGS. 8(   b )- 1 ,  8 ( b )- 2 ,  8 ( b )- 3 ,  8 ( b )- 4 , the directions of the tenon grooves  8   e  of the cylindrical part  8   f  of the holder  8  constituting the valve assembly  5  are aligned with the tenons  3   i  of the case  3  illustrated in  FIGS. 8(   a )- 1 ,  8 ( a )- 2 ,  8 ( a )- 3 , and the tenons are inserted thereinto while the spring  4  interposed between the case  3  and the holder  8  is compressed. Then, after the tenons  3   i  is inserted thereinto to reach the terminal ends of the tenon grooves  8   e , the case  3  and the valve assembly  5  are relatively rotated by approximately 45 degrees, so that the tenons  3   i  are matched with the tenon sliding grooves  8   g  of which are unpenetrated at the upper end thereof; subsequently, the tenons  3   i  are traveled inside the tenon sliding grooves  8   g  by the elastic restoring force of the spring  4  to be pressed on the inner surfaces at the unpenetrated upper ends of the tenon sliding grooves  8   e  as illustrated in  FIGS. 8(   c )- 1 ,  8 ( c )- 2 ,  8 ( c )- 3 , to thereby unite the case  3  and the valve assembly  5 . In this instance, the rotation of the case  3  and the valve assembly  5  is regulated by the rotation regulating side wall  8   h , and therefore the tenons  3   i  and the tenon grooves  8   e  are easily matched with each other during assembly, so that the assembly work can be performed simply and rapidly. After the assembly, the situation that the valve assembly  5  is fallen out from the case  3  can be securely prevented. 
     Embodiment 7 
     As illustrated in  FIG. 9 , in Embodiment 7, a large guiding space  8   j  is provided on the entrance of tenon sliding grooves  8   g  unpenetrated at the upper ends thereof to communicate with the terminal ends of the tenon grooves  8   e  which are formed inside a cylindrical part  8   f  of a holder  8 ; the other arrangement is the same as that of Embodiment 6 illustrated in  FIG. 8 , and thereby the same signs and numerals are assigned to the same parts, and redundant explanations thereof will be omitted. 
     According to Embodiment 7, as illustrated in  FIGS. 9(   b )- 1 ,  9 ( b )- 2 ,  9 ( b )- 3 ,  9 ( b )- 4 , the directions of the tenon grooves  8   e  of the cylindrical part  8   f  of the holder  8  constituting the valve assembly  5  are aligned with the tenons  3   i  of the case  3  illustrated in  FIGS. 9(   a )- 1 ,  9 ( a )- 2 ,  9 ( a )- 3 , and the tenons are inserted thereinto while the spring  4  interposed between the case  3  and the holder  8  is compressed. Then, after the tenons  3   i  is inserted thereinto to reach the terminal ends of the tenon grooves  8   e , when the case  3  and the valve assembly  5  are relatively rotated in one rotatable direction, the tenons  3   i  enter into the tenon sliding grooves  8   g  under guidance of the large guiding space  8   j  which is positioned at the entrance part of the tenon sliding grooves  8   g  unpenetrated at the upper ends thereof. After the entering, the tenons  6   d  are traveled inside the tenon sliding grooves  8   g  by the elastic restoring force of the spring  4  to be pressed on the inner surface at the unpenetrated upper ends of the tenon sliding grooves  8   g  as illustrated in  FIGS. 9(   c )- 1 ,  9 ( c )- 2 ,  9 ( c )- 3 , to thereby unite the case  3  and the valve assembly  5 . As a result, the insertion of the tenons  3   i  into the tenon sliding grooves  8   g  is facilitated and secured, which increases the working efficiency in the assembly of the case  3  and the valve assembly  5 . After the assembly, the situation that the valve assembly  5  is fallen out from the case  3  can be securely prevented. 
     Embodiment 8 
     An air bypass valve device  1  according to Embodiment 8 of the invention illustrated in  FIG. 10  is composed of a case  3 , a spring  4 , and a valve assembly  5 . 
     The case  3  has a bottomed cylindrical part  3   j  interiorly, and as illustrated in  FIGS. 2(   a )- 1 ,  2 ( a )- 2 ,  2 ( a )- 3 , the tenon grooves  3   b  are formed on the bottom surface. Further, a nipple  10  functioning as a pressure port A is formed on the upper surface of the case  3  to communicate with the inside of the bottomed cylindrical part  3   j . Since a spring  4  and a valve assembly  5  are the same as those of Embodiment 1, the same signs and numerals are assigned to the same parts, and redundant explanations thereof will be omitted. 
     According to Embodiment 8, the nipple  10  is integrally formed with the case  3 . Therefore, the number of components can be reduced, and the operation and effect in Embodiment 1 can be obtained. 
     Embodiment 9 
       FIG. 11  is a sectional view showing an air bypass valve device  1  according to Embodiment 9 of the invention, and  FIG. 12  is an exploded perspective view of constitutional components thereof, wherein the air bypass valve device  1  is composed of a case  3 , a spring  4 , and a valve assembly  5 . Then, the feature in which a nipple  10  is integrally formed with the case  3  is the same as that of Embodiment 8. 
     The case  3  has a cylinder body  3   k  interiorly, and as illustrated in  FIGS. 13(   a )- 1 ,  13 ( a )- 2 ,  13 ( a )- 3 , tenons  3   l  are formed symmetrical about an axis on the peripheral surface at the lower end of the cylinder body  3   k , and a space  3   m  is formed inside the cylinder body  3   k  to communicate with the inside of the nipple  10  functioning as a pressure port A which is formed on the upper surface of the case  3 . Further, in the vicinity where the tenons  3   l  are formed on the peripheral surface at the lower end of the cylinder body  3   k , a pressure introducing groove  3   n  is formed at a position orthogonal to the tenons  3   l  with penetrating from inside to outside. 
     According to Embodiment 9, as illustrated in  FIGS. 13(   b )- 1 ,  13 ( b )- 2 ,  13 ( b )- 3 ,  13 ( b )- 4 , the directions of the tenon grooves  8   e  of the cylindrical part  8   f  of the holder  8  constituting the valve assembly  5  are aligned with the tenons  3   l  of the case  3  illustrated in  FIGS. 13(   a )- 1 ,  13 ( a )- 2 ,  13 ( a )- 3 , and the tenons are inserted thereinto while the spring  4  interposed between the case  3  and the holder  8  is compressed. Then, after the tenons  3   l  are inserted thereinto to reach the terminal ends of the tenon grooves  8   e , when the case  3  and the valve assembly  5  are relatively rotated in one rotatable direction, the tenons  3   l  enter into the tenon sliding grooves  8   e  under guidance of a large guiding space  8   j  which is positioned at the entrance part of the tenon sliding grooves  8   e  unpenetrated at the upper ends thereof. After the entering, the tenons  3   l  are traveled inside the tenon sliding grooves  8   e  by the elastic restoring force of the spring  4  to be pressed on the inner surface at the unpenetrated upper ends of the tenon sliding grooves  8   e  as illustrated in  FIGS. 13(   c )- 1 ,  13 ( c )- 2 ,  13 ( c )- 3 , to thereby unite the case  3  and the valve assembly  5 . 
     As a result, owing to the communication between the space in the case  3  and a central hole of the nipple  10  through the pressure introducing groove  3   n , the pressure in the case  3  rapidly follows a change of pressure in the nipple  10 , which increases the working response thereof. Further, the insertion of the tenons  3   l  into the tenon sliding grooves  8   e  is facilitated and secured under the guidance of the guiding space  8   j , and therefore the working efficiency in the assembly of the case  3  and the valve assembly  5  is increased. After the assembly, the situation that the valve assembly  5  is fallen out from the case  3  can be surely prevented. Moreover, since the nipple  10  and the case  3  are integrally formed, the number of parts can be reduced, and the operation and effect in Embodiment 1 can be obtained. 
     INDUSTRIAL APPLICABILITY 
     As described above, in the air bypass valve device  1  of the present invention, the valve assembly  5  is assembled to the case  3  by the tenon insertion structure, and thereby parts thereof can be maintained at a fixed height without affected by the materials of the parts, and therefore the device is suitable for a vehicle-mounted one.