VALVE DEVICE AND HIGH-PRESSURE PUMP USING THE SAME

摘要

A valve device is provided between a high-pressure pump and a fuel tank. A first valve member, an intermediate member and a second valve member are accommodated in a valve housing. The first valve member, which is arranged on a downstream side of the intermediate member, is biased by a first spring in a direction to a first valve seat formed in the intermediate member. The second valve member, which is arranged on an upstream side of the intermediate member, is biased by a second spring in a direction to a second valve seat formed in the intermediate member. When the first valve member is separated from the first valve seat, fuel flows in a forward direction from an upstream-side fuel passage to a downstream-side fuel passage. When the second valve member is separated from the second valve seat, the fuel flows in a reverse direction.

主权项

1. A valve device comprising:
a valve housing; an intermediate member accommodated in the valve housing, an upstream-side fuel passage being formed at an upstream side of the intermediate member and a downstream-side fuel passage being formed at a downstream side of the intermediate member; a forward-flow allowing unit provided inside of the valve housing on the downstream side of the intermediate member, the forward-flow allowing unit allowing a fuel flow in a forward direction from the upstream-side fuel passage to the downstream-side fuel passage when fuel pressure in the upstream-side fuel passage is higher than a first predetermined value; and a reverse-flow allowing unit provided inside of the valve housing, the reverse-flow allowing unit allowing a fuel flow in a reverse direction from the downstream-side fuel passage to the upstream-side fuel passage when the fuel pressure in the downstream-side fuel passage is higher a second predetermined value, wherein the forward-flow allowing unit includes; a first valve member operatively brought into contact with or separated from a first valve seat formed in the intermediate member; and a first spring for biasing the first valve member in a valve closing direction of the first valve member toward the first valve seat, and wherein the reverse-flow allowing unit is arranged in one of the following manners; (i) the reverse-flow allowing unit is arranged on the upstream side of the intermediate member, (ii) the reverse-flow allowing unit is formed in the first valve member or in the intermediate member on a center axis of the valve housing, and (iii) the reverse-flow allowing unit is formed on an upstream-side valve surface of the first valve member.