Pump for supplying high-pressure fuel
AssigneeHitachi Automotive Systems, Ltd.
InventorsShunsuke Aritomi, Kenichirou Tokuo, Satoshi Usui, Shingo Tamura
Life of this patent
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Abstract
A pump for supplying high-pressure includes a plunger, a cylinder, a body, and a holder. The uppermost end surface of the cylinder is an end of the cylinder that is closest to the pressurizing chamber. A first gap formed between the outer periphery of the cylinder and the body in the radial direction is smaller than a second gap formed in the radial direction between the inner diameter of the pressurizing chamber and the outer diameter of the plunger. A radial gap is formed in an entire area of the cylinder in an axial direction thereof.
Claims16
A pump for supplying high-pressure fuel comprising:
- a plunger which pressurizes fuel in a pressurizing chamber;
- a cylinder which guides the reciprocating movement of the plunger on an inner peripheral side face of the cylinder;
- a body in which the cylinder is arranged;
- and
- a holder that is disposed between the cylinder and the body, wherein
- the cylinder has an uppermost end surface that is pressed against the body and which opposes the body, and wherein the entire cylinder is disposed on the side opposite to the pressurizing chamber relative to the uppermost end surface,
- the uppermost end surface of the cylinder is the only surface of the cylinder that directly contacts the body of the pump,
- a radially outwardmost side of the cylinder has a shape that is complementary with a shape of the holder at a given region,
- along a longitudinal direction of a low fuel-pressure portion of the pump, the given region is located in an upper half of the low fuel-pressure portion, and
- the uppermost end surface of the cylinder is an end of the cylinder that is closest to the pressurizing chamber,
- a first gap formed between the outer periphery of the cylinder and the body in the radial direction is smaller than a second gap formed in the radial direction between the inner diameter of the pressurizing chamber and the outer diameter of the plunger,
- a radial gap is formed in an entire area of the cylinder in an axial direction thereof between the cylinder and the body,
- the first gap is smaller than the second gap, and
- a portion of the body projects radially inward so as to directly overlap a first end of the plunger, the first end of the plunger being an axial end with a largest diameter.
A pump for supplying high-pressure fuel comprising:
- a plunger which pressurizes fuel in a pressurizing chamber;
- a cylinder which guides the reciprocating movement of the plunger on an inner peripheral side face of the cylinder;
- a body in which the cylinder is arranged;
- a holder that is disposed between the cylinder and the body configured to fix the cylinder to the body, wherein
- the cylinder is inserted from a lower part of the body and is biased upward in the axial direction by the holder so that an upper end surface of the cylinder that is adjacent to the pressurizing chamber is pressed against the body;
- and
- the upper end surface forms a seal that seals a space between the pressurizing chamber and a low-pressure fuel portion, wherein
- an entirety of the cylinder is disposed on a side that is opposite to the pressurizing chamber from the upper end surface,
- the upper end surface of the cylinder is flat from an inner end of the cylinder to an outer end of the cylinder, and
- a portion of the body projects radially inward so as to directly overlap a first end of the plunger, the first end of the plunger being an axial end with a largest diameter.
Dependencies are inferred from the claim text.