Abstract:
Un galet de came hydraulique d'actionnement de soupape de moteur a combustion interne et autre comprend un corps cylindrique creux (1) ferme a une extremite et monte en coulissement sur un manchon (4) fixe par rapport au corps (1), un piston (8) monte de maniere coulissante dans le manchon (4), l'extremite exterieur des pistons (8) cooperant avec une bielle poussoir (9), une chambre (20) etant definie entre l'extremite interne du piston (16) et l'extremite fermee du corps (1) et contenant un fluide hydraulique. Le deplacement du corps (1) par la came (2) deplace le fluide hydraulique qui deplace le piston (8) dans le manchon fixe (4) pour donner a la bielle de poussee (9) une course plus longue et plus rapide que la course du corps (1).
Abstract:
A hydraulic tappet of the type having a one-way check valve (74) for valve gear of an internal combustion engine is provided which is especially suited for use in smaller displacement, higher r.p.m. engines, Tappets having conventional check valves in some instances experience unsatisfactory operation at higher engine speeds due to excessive internal pressure in the tappet which results in over extension of the tappet. The hydraulic tappet of the invention eliminates this problem and includes a movable plunger assembly (62) received in the tappet body (54). The plunger assembly defines an internal fluid reservoir (72) and, in combination with the tappet body, a fluid cavity (70). The one-way check valve (74) is located within the fluid cavity and comprises a spherical valve member (78) biased by a conical spring (84) into engagement with a valve seat (76) adjacent a fluid passageway connecting the fluid reservoir and the cavity. A retaining cage (79) surrounds the valve member and spring and limits the movement of the valve member away from the valve seat. In the maximum open position the conical biasing spring is compressed to a minimum height substantially 1 equivalent to its wire diameter, thereby permitting the ball to move away from the valve seat without obstruction from the I spring. An opening (88) in the retaining cage allows the valve member to extend partially therethrough to further increase the travel of the ball.
Abstract:
PURPOSE:To miniaturize a hydraulic rush adjuster and make it light-weight by providing a check ball in the hydraulic rush adjuster, and forming release means for an actuator being operating means for said check ball with a form storage alloy. CONSTITUTION:In a case where fuel is cut out over a long period of time when an engine is rotated at a low rpm under low load, temperature of engine oil circulating through a path of from a pressure oil supply device to a supply hole 16, a communication hole 15, and a low pressure chamber 13 is relatively low, and hence a coil-shaped suspension release member 24 comprising a form storage alloy is present in a low temperature phase. Accordingly, a bias spring 25 pushes a check ball 19 downwardly against the suspension release member 24 and a check ball spring 20 for opening an orifice path 10. Therefore, when a body 7 is pushed up by a cam, any oil existent in a high pressure chamber 14 is discharged to the low pressure chamber 13 and the succeeding stages to permit a plunger 8 to be moved realtively downwardly in a body 7, is transmitted to an intake/exhaust valve to result in the intake/exhaust valve being made a non-operation state.
Abstract:
PURPOSE:To eliminate the need for a stage for cutting a relief groove by drawing the open end of a bottomed cylindrical blank material having a tapered shoulder part to form a seat surface consisting of a semispherical surface having a large diameter and forming the part adjacent to the seat surface to an undercut shape. CONSTITUTION:Oil holes 2, 3 are formed to the bottom and circumferential wall of a bottomed cylindrical blank material 1 and an open end 4 is cut even. The end 4 is drawn for a specified length to form a stepped shape having a tapered shoulder part 5. The part near the shoulder thereof is grasped by split dies 11 and an upper die 10 is brought down to draw the open end 4 to a seat surface 6 consisting of the semispherical surface having the diameter larger than the diameter of a drawn part 7 according to the shape of a recessed spherical surface 10a and to form the part adjacent to the surface 6 to an undercut shaped part 8 of the spherical shape having the diameter smaller than the diameter of the surface 6 according to the shape of the inside circumferential top edge of the dies 11. The compressive deformation of the blank material is thus prevented as far as possible and the need for machining the inside circumferential surface at the open end is eliminated.
Abstract:
PURPOSE:To enable to slide a plunger smoothly by a structure wherein the outside diameter of a tubular part formed on the bottom side of the plunger so as to hold a valve cage is made smaller than the sliding part between the plunger and a cylinder. CONSTITUTION:The outer peripheral part of the tubular part 11 formed on the bottom 2b side of a plunger 2 is cut off by the depth of (d) in order to make the outside diameter of the tubular part smaller than that of a sliding part 2c. Because the outside diameter of the tubular part 11 does not become larger than that of the sliding part 2c, even if thermal strain or aging strain occurs on the tubular part 11, the smooth sliding motion of the plunger 2 is performed at all times. Because the plunger can slide smoothly, the outside diameter of the plunger can be made smaller and consequently the whole adjuster can be manufacturized.
Abstract:
PURPOSE:To prevent the generation of knocking by a method wherein an auxiliary spring acting only in the vicinity of the lower dead center of the motion of a plunger is provided in a body for the plunger of the titled device so that a valve clearance at the time of starting an engine is quickly absorbed. CONSTITUTION:The zero lash adjusting device 7 is interposed between a valve driving cam arranged below the device 7 and a locker arm 1 and the plunger 10 is slidably fitted into the tubular bottomed body 8 in such a manner that the plunger 10 is urged upward by a return spring 12. Further, a check valve having a check ball 15 held by a retainer 13 is provided on the lower surface of the bottom of the plunger 10. In this case, the auxiliary coil spring 21 having a short free end is arranged outside the return spring 12. The length of the coil spring 21 is so determined that the coil spring comes into resilient contact with the bottom of the plunger 10 when the engine is stopped and the bottom of the plunger is in contact with a stopper 20.