Abstract:
Since the conventionally the chip seal  14, 16  and the metallic blade spring  15, 17  have been formed separately, assembly efficiency has been poor (for example when the chip seal  14, 16  is inserted, the metallic blade spring  15, 17  detaches and falls out) which lowers productivity. As a result, the cross sectional shape of the chip seal  21  which pushes against the rotor  13  is made in the shape of a letter L.

Description:
This is a divisional of Application Ser. No. 09/219,812 filed Dec. 23, 1998, the disclosure of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a valve timing variation device which controls the timing of the opening and closing of a valve. 
     DESCRIPTION OF THE PRIOR ART 
     FIGS. 7 and 8 are cross sections showing a conventional valve timing variation device. FIGS. 9A and 9B are cross sections showing the structure of a chip seal of a valve timing variation device. In the figures, reference numeral  1  denotes an electronic control unit (hereafter ECU) which controls the oil control valve  2  and the like.  2  is an oil control valve (hereafter OCV) which supplies working oil to the actuator  3  under the control of the ECU  1 .  3  is an actuator which controls the displacement angle of the camshaft  6  with respect to the timing pulley  8  when the working oil is supplied from the OCV  2  and which continuously regulates the timing of the opening and closing of the air intake valve.  4  and  5  are oil passages through which the working oil which is supplied from the OCV  2  flows.  6  is a camshaft which drives the opening and closing of the intake valve of the engine.  7  is a cam of the camshaft  6 .  8  is a timing pulley arranged on one end of the camshaft  6 .  9  is a bearing of the camshaft  6 . 
       10  is a housing mounted so as to be freely rotatable with respect to the camshaft  6 .  11  is a case fixed to the housing  10 .  12  is a bolt which fixes the case  11  to the housing  10 .  13  is a rotor which is fixed to the camshaft  6  and which rotates relative to the case  11 .  14  and  16  are chip seals which prevent the movement of oil between the oil chambers  18  which are separated by the case  11  and the rotor  13 .  15  is a metallic blade spring which is disposed between case  11  and the chip seal  14  and which pressures the chip seal  14  against the rotor  13 .  17  is a metallic blade spring which is disposed between rotor  13  and the chip seal  14  and which pressures the chip seal  16  against the case  11 .  18  are oil chambers which are separated by the case  11  and the rotor  13 . 
     Next the operation of the invention will be explained. 
     Although the valve timing variation device controls the rotational direction of the housing  10  and the timing of the opening and closing of the air intake and exhaust valves of the engine by controlling of the amount of oil flowing into each oil chamber  18 , in order to prevent the movement of oil between the oil chambers  18 , a chip seal  14  is pushed against the rotor  13  and a chip seal  16  is pushed against the case  11 . 
     In other words, as shown in FIG. 9A, the chip seal  14  is pushed against the rotor  13  by the blade spring  15  disposed between the case  11  and the chip seal  14 . Furthermore the chip seal  16  as shown in FIG. 9B, is pushed against the case  11  by the blade spring  17  which is disposed between the rotor  13  and the chip seal  16 . 
     The attachment of the chip seals  14  and  16  is performed by insertion between the case  11  and the rotor  13  in the direction from the left side of FIGS. 9A and 9B (the front of FIG. 8) to the right side (the back of FIG. 8) so that the chip seals  14 ,  16  and the metallic blade springs  15 ,  17  do not become disassembled. 
     Apart from the conventional example given above, a similar arrangement is disclosed in JP-A-9-324611. 
     Since conventional valve timing variation devices are constructed as above, chip seals  14 ,  16  are pushed onto the rotor  13  or the case  11  using blade springs  15 ,  17 . However since the chip seals  14 ,  16  and the blade springs  15 ,  17  have different structures, the problem has arisen that assembly efficiency is extremely poor (for example when the chip seals  14 ,  16  are inserted the blade spring  15 ,  17  becomes detached and fall out) which reduces productivity. 
     SUMMARY OF THE INVENTION 
     The present invention is proposed to solve the above problems and has the objective of obtaining a valve timing variation device which can increase assemblying efficiency when the chip seals are assembled. 
     According to the first embodiment of the invention, the chip seal of the valve timing variation device has the shape of a letter “L” when taken in cross section. 
     According to the first embodiment of the invention, since the cross sectional shape of the chip seal has the shape of a letter “L”, the efficiency of assembling the chip seal can be increased. 
     According to the second embodiment of the present invention, the valve timing variation device is adapted to integrally form a chip seal and a flexible member. 
     According to the second embodiment, since the chip seal and the flexible member are formed integrally, assemblying efficiency of the chip seal is conspicuously increased. 
     According to the third embodiment of the present invention, the valve timing variation device is adapted to insert a blade spring into the chip seal. 
     According to the third embodiment, since the blade spring is formed to be inserted into the chip seal, it is possible to avoid the deficiency of the chip seal and the blade spring disassembling during assembly. 
     According to the fourth embodiment of the present invention, the valve timing variation device is adapted so that both legs of the chip seal are bent to form a flexible member. 
     According to the fourth embodiment, since both legs of the chip seal are bent to form a flexible member, it is possible to reduce manufacturing costs and at the same time conspicuously improve assembling efficiency of the chip seal. 
     According to the fifth embodiment of the present invention, the valve timing variation device is adapted to fix the flexible member which has lower hardness than the chip seal to the chip seal. 
     According to the fifth embodiment, by fixing the flexible member which has lower hardness than the chip seal to the chip seal, it is possible to lower manufacturing costs and to conspicuously increase assembling efficiency of the chip seal. 
     According to the sixth embodiment of the invention, the valve timing variation device adapted to construct the member on the rotor side of the chip seal using soft flexible resin. 
     According to the sixth embodiment, using soft flexible resin to construct the member on the rotor side of the chip seal enables the flexible member to be dispensed with. 
     According to the seventh embodiment of the present invention, the valve timing variation device is adapted so that the chip seal is pushed to the case side by the flexible member. 
     According to the seventh embodiment, since the chip seal is pushed to the case side by the flexible member, it is possible to prevent the movement of oil between the oil chambers which are separated by the case and the rotor. 
     According to the eighth embodiment, the valve timing variation device is adapted so that the chip seal is pushed to the rotor side by the flexible member. 
     According to the eighth embodiment, since the chip seal is pushed to the rotor side by the flexible member, it is possible to prevent the movement of oil between the oil chambers which are separated by the case and the rotor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A and 1B are cross sections which show the structure of a chip seal of a valve timing variation device according to the first embodiment of the present invention. 
     FIGS. 2A and 2B are cross sections which show the structure of a chip seal of a valve timing variation device according to the second embodiment of the present invention. 
     FIGS. 3A and 3B are cross sections which show the structure of a chip seal of a valve timing variation device according to the third embodiment of the present invention. 
     FIGS. 4A and 4B are cross sections which show the structure of a chip seal of a valve timing variation device according to the fourth embodiment of the present invention. 
     FIGS. 5A and 5B are cross sections which show the structure of a chip seal of a valve timing variation device according to the fifth embodiment of the present invention. 
     FIGS. 6A and 6B are cross sections which show the structure of a chip seal of a valve timing variation device according to the sixth embodiment of the present invention. 
     FIG. 7 is a cross section showing a conventional valve timing variation device. 
     FIG. 8 is a cross section showing a conventional valve timing variation device. 
     FIGS. 9A and 9B are cross sections which show the structure of a chip seal of a valve timing variation device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiments of the present invention are explained below. 
     Embodiment 1 
     FIGS. 1A and 1B are cross sections which show the structure of a chip seal of a valve timing variation device according to the first embodiment of the present invention. In the figures, reference numeral  11  denotes a case fixed to a housing  10 ,  11   a  is a notch of the case  11  which stores the chip seal  21  and  13  is a rotor which fixed to the camshaft  6  and which rotates relative to the case  11 .  13   a  is a notch of the rotor  13  which stores the chip seal  23 .  21  and  23  are chip seals which prevent the movement of oil between the oil chambers  18  which are separated by the case  11  and the rotor  13 .  21   a  and  23   a  are distal sections of the chip seals  21 ,  23 .  22  is a metallic blade spring (flexible member) which is disposed between the case  11  and the chip seal  21  and which pressures the chip seal  21  against the rotor  13 .  24  is a is a metallic blade spring (flexible member) which disposed between the rotor  13  and the chip seal  23  and which pressures the chip seal  23  against the case  11 . 
     Next the operation of the invention will be explained. 
     The valve timing variable device controls the axial direction of the housing and the timing of the opening and closing of the exhaust valve and the air intake valve of an engine by controlling the amount of oil entering the oil chambers  18 . In order to prevent the movement of oil between each oil chamber  18 , a chip seal  21  is pressed against the rotor  13  and a chip seal  23  is pressed against the case  11 . 
     In other words, as shown in FIG. 1A, the chip seal  21  is pressed against the rotor  13  by the metallic blade spring  22  disposed between the case  11  and the chip seal  21 . 
     The chip seal  23  as shown in FIG. 1B is pressed against the case  11  by the metallic blade spring  22  disposed between the rotor  13  and the chip seal  23 . 
     However the chip seals  21 ,  23  are different from conventional chip seals  14 ,  16 . Their cross sectional shape is in the shape of a letter L and the sealing performance of the lateral sections of the chip seals  21 ,  23  is improved as the lateral sections of the chip seals  21 ,  23  are stored in the notches  11   a,    13   a  of the rotor  13  and the case  11 . 
     The assembly of the chip seal  21 ,  23  is performed by insertion between the case  11  and the rotor  13  from the left side of FIGS. 1A and 1B (the front of FIG. 8) towards the right side (the rear of FIG. 8) so that the chip seals  21 ,  23  and the metallic blade springs  22 ,  24  do not become disassembled. The insertion of the tip  21   a,    23   a  of the chip seals  21 ,  23  is easy due to the fact that the tip  21   a,    23   a  of the chip seals  21 ,  23  is narrow in comparison with conventional chip seals  14 ,  16 . Hence the ease of assembly of the chip seal can be improved. 
     Embodiment 2 
     In embodiment 1 above, the L-shaped cross sectional shape of the chip seal  21 ,  23  was explained. However as shown in FIGS. 2A and 2B, the chip seal may be integrated with a flexible member. 
     In other words, the chip seal and the flexible member are integrated by the insertable form of the metallic blade spring  26 ,  28  with respect to the chip seal  25 ,  27 . 
     In this way, when the chip seal  25 ,  27  is assembled, the chip seal  25 ,  27  and the metallic blade spring  26 ,  28  do not become disassembled and assembling efficiency is conspicuously improved. 
     Embodiment 3 
     In embodiment 2 above, the chip seal was explained as integrated with the flexible member. However as shown in FIGS. 3A and 3B, both legs of the chip seal may be bent to form a flexible member. 
     In other words, the legs  29   a,    29   b,    30   a,    30   b  of the chip seal  29 ,  30  have the shape as shown in FIG.  3  and the legs  29   a,    29   b,    30   a,    30   b  of the chip seal  29 ,  30  may be flexible. 
     In this way, as a flexible member such as a metallic blade spring becomes redundant, costs are reduced and the assembly efficiency is conspicuously improved. 
     Embodiment 4 
     In embodiment 2 above, the chip seal was explained as integrated with the flexible member. However as shown in FIGS. 4A and 4B, a flexible member of lower hardness than the chip seal may be fixed to the chip seal. 
     In other words, as shown in FIG. 4A, when the chip seal  31   a  is pushed against the rotor  13 , the chip seal  31  on the rotor side  13  is constructed using a hard highly slidable resin such as nylon or carbon. The chip seal  31   b  (flexible member) on the case side  11  is constructed using a soft resin with high flexibility such as rubber or elastomer. 
     Furthermore as shown in FIG. 4B, when the chip seal  32   a  is pushed against the case  11 , the chip seal  32   a  on the case side  11  is constructed using a hard highly slidable resin such as nylon or carbon. The chip seal  32   b  (flexible member) on the rotor side  13  is constructed using a soft resin with high flexibility such as rubber or elastomer. 
     In this way since a flexible member such as the metallic blade spring becomes redundant, costs are reduced and assembling efficiency is conspicuously improved. 
     Embodiment 5 
     In embodiment 3 above, the flexible chip seal was explained as having flexibility in the leg sections. However as shown in FIGS. 5A and 5B, the slidable surface of the chip seals  29 ,  30  and the leg sections are laminated and both legs  29   a,    29   b,    30   a,    30   b  may be constructed using a soft highly flexible resin such as rubber or elastomer. Hence the same effect as embodiment 3 can be achieved. 
     Embodiment 6 
     In embodiment 4 above, a bilayer of two resins of different hardness was formed to construct the chip seal. However as shown in FIGS. 6A and 6B, the cross sectional shape of the chip seal may be in the shape of a letter L. 
     In this way, the same effect as embodiment 4 above is achieved and the performance of the seal on the lateral surface of the chip seal is enhanced.