| 摘要 |
<p>1. A diaphragm pump for the supply of fuel to a heat engine, of the type comprising an upper body (12) of composite synthetic material of good mechanical strength and resistance to heat and a lower body (14) made of composite synthetic material or metal, said bodies being hollow and open at one end, their free edges being fitted together, gripping between them the peripheral edges of a deformable diaphragm (16) and a valve-carrying element (18), the upper body being internally divided by a partition (30) into an inlet chamber (32) communicating with the fuel tank by way of an inlet orifice (42) and a delivery chamber (34) communicating with the carburettor of the engine by way of a delivery orifice (44) and by way of a tank return orifice optionally with the tank, said orifices being provided with tubular intake, delivery and tank return connection portions (46, 48 and 60 respectively), the two bodies being held in the assembled condition by means of a resilient sheet metal collar (20) which is cripmed over the flanges formed by the edges of said bodies, said pump being characterised in that at least the tubular tank return connection portion (60) are metal and each comprise a terminal portion or base portion successively provided on its side wall with a bevel (70) on its entry edge, followed by at least one annular groove (71, 72), an annular zone (73) provided with knurling, an annular relief portion (74) delimited by a collar (79) of a diameter which is larger than that of the base portion, said base portion being sealingly embedded in an impression portion (28) formed in a hollow configuration in the side wall and/or the end wall of the upper body, which communicates with the interior of the latter through an orifice (44) and which forms in the interior of the upper body a boss which is immersed in the fuel, the sealed nature of the assembly and tensile strength and resistance to rotation of the tubular connection portions being ensured by the composite synthetic material of the impression portion, when raised to its softening temperature, filling the different relief regions of the base portion.</p> |
