FUEL INJECTION RATE CONTROL APPARATUS FOR V-ENGINES

Abstract: This control has a fuel injection pump (1) provided with a governor (2) and mounted on one side portion of a cylinder block. A governor-free fuel injection pump is mounted on the other side portion of the cylinder block. A link mechanism consists of a connecting shaft (41) provided in front of the two fuel injection pumps so that the connecting shaft can be turned freely to transmit the movement of a rack rod (3) of the governor-carrying fuel injection pump (1) to a rack rod (3) of the other fuel injection pump (1'). A pair of levers are fixed to both sides of the connecting rod to project in the opposite directions. A pair of links connect these levers and two rack rods together.

Description: The present invention relates to a fuel injection rate control apparatus for a V-engine including a fuel injection pump provided with a governor and mounted on one side of a V-engine cylinder block, and a fuel injection pump having no governor which is mounted on the other side of said V-engine cylinder block. Conventionally, a pair of fuel injection pump bodies are mounted on both sides of the cylinder block of a V-engine such that when both rack rods move in the same direction, the same function is displayed. One of the fuel injection pumps is provided with a governor, while the other fuel injection pump has no governor, and the movement of the rack rod of the fuel injection pump provided with the governor is transmitted to the rack rod of the fuel injection pump having no governor through a link mechanism. That is, a link mechanism such as that shown in Fig. 1 is widely used. In Fig. 1, the symbols a and a′ both represent a fuel injection pump. The fuel injection pump a′ is mounted in the state in which it faces the same direction as the fuel injection pump a. In other words, both fuel injection pumps a and a′ are mounted such that when the respective rack rods c move in the same direction, the same function is displayed. The symbol b represents a pump governor which is mounted on the fuel injection pump a so as to control the fuel injection rate by moving the rack rod c of the fuel injection pump a in correspondence with the change of the engine load. Since no governor is mounted on the fuel injection pump a′, the movement of the rack rod c of the fuel injection pump a′ is transmitted to the rack rod c of the fuel injection pump a by a link mechanism composed of levers d₂₋₁ and d₂₋₂ which are fixed to a connecting shaft d₁ in such a manner as to project in the same direction from both sides thereof and a link d₃. The above-described conventional control apparatus is disadvantageous in that when the engine is inclined forward, the rotational speed of the engine is increased because the levers d₂₋₁ and d₂₋₂ are moved in the direction of increasing the fuel under the weights of their own gravities, while the rotational speed of the engine is reduced when it is inclined backward. The JP-A 52-148730 corresponding to the US-A 4 150 650 discloses a centrifugal governor having a counterbalance for compensating the influence of inertia or gravity on control members of an injection pump. JP-A 58-34272 discloses an apparatus for lightening a drive power of a speed governor of an internal combustion engine (V-engine) which comprises a weight fixed on a governor shaft in such a manner that the weight acts on the shaft to compensate a force caused by the weight of the rack due to inclination of a cylinder. Accordingly, it is an object of the present invention to eliminate the above-described problems in the prior art and to provide a fuel injection rate control apparatus for a V-engine of the above type by which the fuel injection is controlled independently of the weight of the levers. To achieve this aim, the present invention provides a fuel injection rate control apparatus for V-engine of the above kind which is characterized in that a link mechanism is provided which is composed of a connecting shaft rotatably provided in front of the two fuel injection pumps so as to transmit the movement of a rack rod of said fuel injection pump provided with said governor to the rack rod of the fuel injection pump having no governor, a pair of levers fixed to both sides of said connecting shaft so as to project in the opposite directions to each other with respect to said connecting shaft and a pair of links connecting said levers and the two rack rods together, so that said rack rods do not move under the weights of said levers which are fixed to both sides of said connecting shaft even if said engine is inclined forward or backward. The fuel injection rate control apparatus is characterized in that the fuel injection pump provided with the governor is so controlled as to increase the fuel injection rate when the rack rod is projected and decrease it when the rack rod is contracted, while the fuel injection pump having no governor is so controlled as to decrease the fuel injection rate when the rack rod is projected and increase it when the rack rod is contracted. The above and other advantages, features and objects of the invention will be apparent to those who are skilled in the art from the following description of the preferred embodiment thereof, taken in conjunction with the accompanying drawings. Fig. 1 is a schematic perspective view of a conventional fuel injection rate control apparatus for a V-engine; and Fig. 2 is a schematic perspective view of an embodiment a fuel injection rate control apparatus for a V-engine according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be explained with reference to the accompanying drawings. Fig. 2 is a perspective view of an embodiment of the present invention. In Fig. 2, the reference numerals 1 and 1′ both represent a fuel injection pump. The fuel injection pumps 1 and 1′ are mounted on the respective sides of a cylinder block (not shown) in the state in which both pumps face the opposite directions to each other. In other words, when the respective rack rods c move in the opposite directions, the same function is displayed. The reference numeral 2 represents a governor, which is a commonly mass-produced inexpensive one, and which is mounted on one fuel injection pump 1 so as to control the fuel injection rate by moving a rack rod 3 of the fuel injection pump 1′ in correspondence with the engine load. Since the other fuel injection pump 1′ is not provided with the governor 2, a link mechanism 4 is provided which is composed of a connecting shaft 4₁ rotatably provided in front of both fuel injection pumps 1 and 1′, a pair of levers 4₂₋₁ and 4₂₋₂ fixed to both sides of the connecting shaft 4₁ so as to project in the opposite directions to each other with respect to the connecting shaft 4₁ and links 4₃ connecting these levers 4₂₋₁ and 4₂₋₂ and the rack rods of the respective fuel injection pumps 1 and 1′ together, so that the movement of the rack rod 3 of the fuel injection pump 1 provided with the governor is transmitted to the rack rod 3 of the fuel injection pump 1 having no governor so as to control the fuel injection pump 1′. Since the levers 4₂₋₁ and 4₂₋₂ are fixed to both sides of the connecting shaft 4₁ so as to project in the opposite directions to each other with respect to the connecting shaft 4₁, their own weights are cancelled by each other. Therefore, the weights of the levers 4₂₋₁ and ₄₂₋₂ do not influence the movement of the rack rods 3 whether the engine is inclined forward or backward and the rotational speed of the engine is not varied whether the engine is inclined forward or backward. Thus, it is possible to constitute a fuel injection rate control apparatus for a V-engine which does not vary the rotational speed of the engine whether the engine is inclined forward or backward even by using a commonly mass-produced inexpensive governor.

Claims: 1. A fuel injection rate control apparatus for a V-engine including a fuel injection pump (1) provided with a governor (2) and mounted on one side of a V-engine cylinder block, and a fuel injection pump (1′) having no governor which is mounted on the other side of said V-engine cylinder block, characterized in that a link mechanism (4) is provided which is composed of a connecting shaft (4₁) rotatably provided in front of the two fuel injection pumps so as to transmit the movement of a rack rod (3) of said fuel injection pump (1) provided with said governor (2) to the rack rod (3) of the fuel injection pump (1′) having no governor, a pair of levers (4₂₋₁, 4₂₋₂) fixed to both sides of said connecting shaft so as to project in the opposite directions to each other with respect to said connecting shaft and a pair of links (4₃) connecting said levers and the two rack rods (3,3) together, so that said rack rods do not move under the weights of said levers which are fixed to both sides of said connecting shaft even if said engine is inclined forward or backward. 2. A fuel injection rate control apparatus for a V-engine according to claim 1, further characterized in that said fuel injection pump (1) provided with said governor (2) is so controlled as to increase the fuel injection rate when said rack rod (3) thereof is projected and decrease said fuel injection rate when said rack rod is contracted, while said fuel injection pump (1′) having no governor is so controlled as to decrease said fuel injection rate when said rack rod (3) thereof is projected and increase said fuel injection rate when said rack rod is contracted.

Inventors: FUJIMOTO, KATSUYA, NIHEI, CHUUKICHI, TANOZAKI, TSUNEO, UENO, MITSURU, YAMAMOTO, YUKIO
Applicants: KABUSHIKI KAISHA KOMATSU SEISAKUSHO
Application year: 1988
Main classification: F02D1
IPC codes: F02D1, F02D11