Abstract:
This invention relates to improvements in an air-cleaner for internal combustion engines, more particularly, to an improved air-cleaner having such sound-silencing construction that an air-cleaner element is removably fixed in a vibration-isolating cover which is provided in the housing of the air-cleaner.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention relates to improvements in an air-cleaner, more particularly, to an improved air-cleaner having sound-silencing construction for internal combustion engines. 
     Conventionally, the housing of the air-cleaner for internal combustion engines is box-shaped and is made of thin steel sheet or synthetic resin sheet in order to make it lighter in weight and also to improve production efficiency. Therefore, the housing of air-cleaner itself is easy to resonate with the pulsation developed by inspiratory pressure of the internal combustion engine. This results in causing more noises. 
     The present invention has for an object to eliminate the above-mentioned defect of the conventional air-cleaner and is intended for providing the air-cleaner of such double construction that an air-cleaner element is removably fixed in a vibration-isolating cover which is provided in the housing of the air-cleaner. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The nature and advantages of the present invention will be understood more clearly from the following description made with reference to the accompanying drawings, in which: 
     FIG. 1 is a front view of the internal construction of the air-cleaner according to the present invention, partly broken away. 
     FIG. 2 is a longitudinal section, at the center, of a vibration-isolating cover in which an air-cleaner element is accommodated. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In FIG. 1, numerals 1, 2 and 3 denote an air-cleaner housing, an air-cleaner element and a vibration-isolating cover respectively. The air-cleaner housing 1 is provided with an inlet 4. The air taken in through the inlet 4 is led as shown by arrows A in FIG. 1, is filtered by the air-cleaner element 2 and is further led into a carburetor (not shown in the drawings) through an outlet 5. 
     As to the construction of the afore-mentioned air-cleaner element 2 and vibration-isolating cover 3, as shown in FIG. 2, the cleaner element 2 is conically and hollow in shape and comprises a filter 6, such as felt, and an air-permeable liner 7, such as wire cloth, supporting the filter 6. The vibration-isolating cover 3 consists of an upper truncated portion 8 and a lower cylindrical portion 9. The upper portion 8 is open at its bottom side and has at its upper side an air inflow opening 10, at the inner surface of which an inverted, truncated connecting spider 12 is provided which has ventilating windows 11 therethrough and a hollow guide post 20 extending upwardly through the conical portion thereof. Connected to the lower end of the connecting spider 12 and surrounding the guide post 20 is a dish-shaped support plate 13. The lower portion 9 is open at its upper side and has at its base an air outflow opening 14. Fixed to the outer circumference of the air outflow opening 14 is the bottom of a truncated support 16 provided with many ventilating holes 15. A binding bolt 17, which is to pass through guide post 20, is fixed to the top end of the support 16. Fixed to the opening 14 of the lower portion 9 is the outlet 5. At the outer circumference of the opening 14 is fixed a guide bolt 18. 
     The afore-mentioned element 2 is placed in such a fashion that it covers the support 16 of the lower portion 9. The upper portion 8 engages with the lower portion 9, whereby the upper end of the element 2 makes direct contact with the support plate 13 and both are fixed together by fastening the binding bolt 17 with a nut 19. Thus, the vibration-isolating cover 3 as a whole is fixed to the air-cleaner housing 1 by means of the guide bolt 18. 
     As mentioned above, in the air-cleaner according to the present invention, the element is accommodated in the double construction comprising the housing and the vibration-isolating cover. Under this arrangement, the inspiratory pressure is kept from acting directly on the wall surface of the air-cleaner housing, with the result that noises usually caused by resonation with pulsation of the inspiratory pressure are reduced to a great extent. 
     Besides, according to the present invention the vibration-isolating cover is integral with the air-cleaner housing and such integral construction has large effect of silencing the pulsating inspiratory sound, which, coupled with vibration-isolating effect of the aforementioned air-cleaner housing, can silence noises to a large extent.