Zexel Gmbh

Jun Matsubara

Kenichi Kubo

Hiroshi Ishiwata

Kazuaki Narikiyo

Hisashi Nakamura

Ken-ichi Kubo

Noriyuki Abe

Tsunayoshi Motoyoshi

Hajime Machida

Atsushi Ueda

Toru Yokota

Kazuo Inoue

Satoshi Kitamura

Toru Yamakawa

Katsuhiro Shimokoshikimachi

Tsumayoshi Motoyoshi

Mitsunori Urano

Ken'ichi Kubo

In a distributor type fuel injection pump and a power transmission pump for transmitting power to the fuel injection pump, when a rotation system member of the injection pump is seized if anything should happen, only an injection pump is damaged to thereby greatly reduce damage to an engine. To this end, an annular groove is provided in a rotor to which power from the engine is transmitted, and the annular groove constitutes a frail portion of the rotor. The annular groove is positioned along the rotor so that all or most of the sliding portions of the rotor are located on a side of the groove opposite to a power supply side. When seizure occurs in the sliding portions of the rotor to prevent rotation, the rotor is twisted off at the annular groove by the power from the engine, so that rotation of a power supply side portion of the rotor is not prevented.

Distributor type fuel injection pump and power transmission device

In a spill control apparatus for a fuel injection system in which a sleeve is externally fitted to a rotor, and the position of the sleeve relative to the rotor is used to adjust the communication timing between a port on the rotor and a port on the sleeve, the port formed at the rotor is constituted of a first indented portion formed over a specific angle of rotation and a second indented portion formed to achieve specific spill characteristics. The second indented portion is formed continuous to the front end of the first indented portion in the direction of rotation and the contour of the second indented portion is continuous to the contour of the first indented portion which is constituted of oblique sides which extend toward the front relative to the direction of rotation. The length of the rotor port in the axial direction may be set smaller than the length of the port formed on the sleeve in the axial direction. Thus, it is possible to inhibit the entry of dust particles into the area between the rotor and the sleeve, reducing the incidence of scarring induced on the sliding contact surfaces of the rotor and sleeve, and preventing the seizure of the rotor and the sleeve.

Spill control apparatus for fuel injection system

A rotor that rotates in synchronization with an engine is provided inside a housing and a cam ring is provided outside and around the rotor so that plungers are caused to move reciprocally in the direction of the radius by the cam ring as the rotor rotates. At both sides of the cam ring, support members (barrel 8, bearing support member 6) constituted of the same material as that of the cam ring are secured to the housing and to both sides of the cam ring, and these support members alone hold the cam ring from both sides rotatably. A connecting rod connecting the cam ring and the timer mechanism is formed as an integrated part of the cam ring. The clearance between the cam ring and the members holding it can be set small so that the vibration of the cam ring is reduced to minimize the impact noise made by the cam ring and wear of the cam ring. In addition, the connection strength between the cam ring and timer mechanism is increased.

Inner cam system distributor type fuel injector

In an inner-cam system fuel injection pump, two balance ports that are offset symmetrically relative to a distribution port in a circumferential direction to form a Y-shape are formed at a rotor. The opening ends of the balance ports and the opening end of the distribution port are positioned on the same plane that is perpendicular to the axis of the rotor. The offset angle .theta. by which the balance ports are offset in the circumferential direction relative to the axis of the distribution port, the opening area S.sub.1 of the distribution port and the opening area S.sub.2 of each of the balance ports are set to satisfy a relationship expressed as S.sub.1 =.vertline.2.multidot.S.sub.2 .multidot.cos .theta..vertline.. The phase intervals of the fuel delivery passages and the phase interval of the two balance ports are set equal to each other. Seizure at the area where the rotor slides in contact with its supporting member is prevented effectively and stable injection characteristics are achieved by equalizing the residual pressures in the individual fuel delivery passages.

Distributor type fuel injection pump

In an inner cam type injection pump, the side surface of the protruding portion of each of the plungers facing the compression space is formed in a projecting shape in the area where the plunger changes from the base end side into the front end. Specific forms of the projection include a structure constituted with slanted surfaces over a plurality of stages with different inclinations relative to the axis of the plunger, an arc form and a structure provided with a overhanging portion formed on the side surface of the protruding portion, which does not overhang the base end, projecting out from the side surface. This will prevent collision at the shoulder portion of the plunger and, consequently, prevent the deformation at the shoulder portion and ensures that plungers will not have sliding failures or become seized. Even when plungers collide, the sliding of the plungers will not be affected, ensuring that plungers do not have sliding failures or become seized.

Inner cam type fuel injection pump having modified plungers

The movement of a control sleeve in the circumferential direction is made to interlock with the movement of a timer piston to ensure that the control sleeve has a function of pre-stroke control. In order to interlock the movements of the timer piston and the control sleeve, they are linked with first through third link members and the control sleeve is caused to rotate in the circumferential direction at a specific ratio relative to the quantity of movement of the timer piston. In a fuel injection system provided with an actuator for adjusting the fuel force feed end by moving the control sleeve in the direction of the axis and an actuator for controlling the timing with which the cam lift begins, pre-stroke control can be achieved without requiring a separate actuator, with a simple mechanical structure.

Fuel injection system

Inflow/outflow ports are provided in either one of a distribution member for distributing compressed fuel or a control sleeve which is externally fitted around the distribution member. Each of the ports includes a slit extending therefrom. At the other one of the distribution member and the control sleeve, an intake-cutoff hole that communicates sequentially with the inflow/outflow ports and a pilot port which communicates with the slits during part of the force feed period are provided. Since the fuel flows out through the slits during part of the force feed period, pilot injection can be more easily achieved prior to the main injection during low speed rotation and fuel is less likely to be diverted through the slits due to the constricting effect during high speed rotation so that only the main injection is performed. As a result, a distributor type fuel injection pump which achieves pilot injection in the idling range and in the no-load range, and cancels the pilot injection in the full-load range is provided.

A low pressure side fuel path extending from a fuel inflow port to a feed pump, and a chamber, which can communicate with an inflow/outflow port, are formed by partitioning inside a housing. A cam ring, shoes and rollers are provided in the low pressure side fuel path to induce low pressure, low temperature fuel into the area surrounding the rollers. A space that communicates with the low pressure side fuel path without constriction is formed on the upstream side on the back surfaces of the shoes. A phase of the cam ring and the control sleeve is fixed with the adapter provided on the boundary of the low pressure side fuel path and the chamber. An intake passage communicating with the intake port may be formed in the adapter to shorten the intake path. The area around the rollers, which tends to become heated in an inner-cam type fuel injection pump, is cooled efficiently, cam jump is reduced, control of advance angle is performed separately and independently of the fuel injection quantity control, and the efficiency of fuel intake is improved.

Two stage fuel injection pump with second stage located in the first

A servo valve type timer for controlling a fuel injection timing on the basis of the difference in pressure between a high-pressure chamber and a low-pressure chamber, including a timer piston for adjustment of a fuel injection timing which is disposed between the high-pressure chamber and the low-pressure chamber so as to be slidable between the high-pressure chamber and the low-pressure chamber and is operated in accordance with a fuel pressure introduced into the high-pressure chamber and/or the low-pressure chamber, a servo valve for controlling the operation of the timer piston, and a pressure control member for adjusting the fuel pressure of the low-pressure chamber.

Servo valve type timer for fuel injection pump

The inside of the housing is divided into a low pressure fuel area formed from a fuel inflow port through a feed pump 4 and a high pressure fuel area that can communicate with inflow/outflow ports for fuel. For instance, the low pressure fuel area may be formed as a path extending from the fuel intake port that communicates with the circumferential area of the front end of the rotor to the feed pump via the circumferential area of the rotor support member and a passage for inducing fuel from the high pressure fuel area to the circumferential area of the front end of the rotor may be formed between the rotor and its support member. The flow of fuel in the area where the rotor slides in contact with its support member is ensured, and oil film loss is prevented. With this, cooling and good lubrication in the rotor sliding contact area, where heat is likely to be generated, are promoted, to prevent seizure in the sliding contact area. Also, ports that open into the area where the rotor slides in contact with its support member and that communicates with the compression space may be provided in the rotor so that compressed fuel is supplied directly to the sliding contact area.

Distributor-type fuel injection pump

In an innercam system fuel injection pump, plungers 15 are provided in the direction of the radius of a rotating member 10 which rotates in synchronization with the engine. A cam ring 18, which regulates the movement of the plungers, is fixed in a housing 2. A first sleeve 25 for regulating the timing with which a cutoff port 22 opens and a second sleeve 26 for regulating the timing with which an intake port 21 opens are externally fitted on the rotating member 10 in such a manner that they can slide freely. The first sleeve 25 and the second sleeve 26 interlock with each other in a specific relationship and a timer mechanism 40, which is directly linked to the second sleeve 26, controls the quantity of rotation of the second sleeve 26. With this, stable injection timing control can be achieved.

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Higashimatsuyama, Japan

Jun Matsubara