US3750640A - Emergency stopping device for a fuel-injection internal combustion engine - Google Patents

Abstract

In an internal combustion engine of the fuel-injection type fed with fuel by injection pumps, each pump comprising a piston operated by an actuating mechanism releasably connected thereto and with tripping means adapted to slow down and to stop the engine in case of overspeed, at least one servo-motor operated by said tripping means for acting upon said fuel-injection pumps, an emergency stopping arrangement wherein each one of said pumps is provided with an individual servo-motor acting directly upon the piston of said pump to disconnect said piston from its actuating mechanism.

Description

United States atent Kiihn 1 51 Aug. 7, 1973 [541 EMERGENCY STOPPING DEVICE FOR A 2,719,521 10/1955 King et a1. 123/198 DB FUELJNJECTIQN INTERNAL 2,831,474 4/1958 King et a1. 123/198 DB 2,854,964 10/1958 Wagner 123/198 DB COMBUSTION ENGINE 3,388,695 6/1968 O'Donnell 123/198 D Inventor:

Assignee:

Filed:

Appl. No.:

Karl Walter Kiihn, Saint-Germain-en-Laye, France Societe DEtudes De Machines Thermiques, Saint-Denis, France Nov. 22, 1971 Foreign Application Priority Data Dec. 31, 1970 France 7047558 US. Cl 123/198 D Int. Cl. F02b 77/00 Field of Search 123/198 D, 198 DB References Cited UNITED STATES PATENTS Eppens 123/198 DB Primary E;qmin er-C. J. Husar Attorney-Francis T. Carr and Theodore Ordman [57] ABSTRACT In an internal combustion engine of the fuel-injection type fed with fuel by injection pumps, each pump comprising a piston operated by an actuating mechanism releasably connected thereto and with tripping means adapted to slow down and to stop the engine in case of overspeed, at least one servo-motor operated by said tripping means for acting upon said fuel-injection pumps, an emergency stopping arrangement wherein each one of said pumps is provided with an individual servo-motor acting directly upon the piston of said pump to disconnect said piston from its actuating mechanism.

3 Claims, 5 Drawing Figures Hummus 1:915 3750 s40 SHEET 1 BF 4 EMERGENCY STOPPING DEVICE FOR A FUEL-INJECTION INTERNAL COMBUSTION ENGINE The present invention relates to and has essentially for its object an emergency stopping device for an internal combustion engine of the fuel-injection type, for instance a Diesel engine.

In the known devices, in case of engine overspeed caused by an abrupt disappearance of the resisting moment, the tripping means, for instance of the centrifugal type, slowing down or stopping the engine opens a pressurized-fluid intake valve of the engine. The said fluid supplied to a single actuator, the piston of which acts collectively and simultaneously upon all the actuating toothed racks of the injection pumps, so as to stop the injection of fuel from all the pumps. However, when a casual jamming of the toothed rack or the mechanical transmission between the actuator and the rack occurs, such a safety device can no longer work. This leads to serious difficulties such as overspeed and racing" which may severely damage the engine.

The present invention has essentially for its purpose to avoid the difficulties just mentioned, by providing for each pump a mechanically independent emergency stopping of the discharge of the said pump, without acting upon its actuating member, for instance its toothed rack.

To this end, the emergency stopping device according to the invention is characterized in that each of the said pumps is provided with an individual servo-motor acting directly upon the piston of the said pump so as to disconnect its actuating member.

According to another feature of the present invention, each said servo-motor comprises an actuator supplied with pressurized fluid by the said tripping means and mounted on the corresponding injection pump, and a lever connected,'on the one hand, to the piston of the said pump and, on the other hand, to the piston of the said actuator and pivotally mounted between its two ends at a fixed point of the said actuator and/or the body of the said pump.

The invention will be better understood and other objects, characteristics and advantages thereof will appear as the following description proceeds, with reference to the appended drawings given solely by way of example illustrating several forms of embodiment of the invention and wherein:

FIG. 1 is an emergency stopping system according to the invention, used in connection with four fuelinjection pumps;

FIG. 2 is a vertical sectional view of an individual emergency stopping device mounted on a fuel-injection pump;

FIG. 3 shows the device partially in vertical section upon the line IIIIII of FIG. 2 (left side of the device), and partially in vertical section (right side of the device) with a partially broken away view of the servomotor;

FIG. 4 is a longitudinal sectional view upon the line IV--IV of FIG. 2;

FIG. 5 is a partial longitudinal sectional view upon the line V-V of FIG. 2.

The appended drawings and more particularly FIG. 1 diagrammatically illustrate a system of automatic regulation of the injection pumps 1 by means of a regulator 50 acting simultaneously upon the toothed racks 7 of the pumps through the medium ofa linkage comprising a cranked shaft 51 connected with the regulator by a resilient connecting member 52 which, in case of need, enables the engine to be stopped by manually actuating the toothed racks by means of the crank 8. The safety device according to the invention is adapted to stop four fuel-injection pumps in case of overspeed or racing of an internal combustion engine, for instance a Diesel engine. During the operation of the engine under normal working conditions, the outlet conduit 6" of the overspeed-controlled tripping means 5 is connected with the conduit 6 through which the oil is supplied to the four actuators 2. The pressurized oil in the conduit 6' is thus discharged through the outlet conduit 6". Under overspeed conditions, the centrifugal-acting tripping means 5, which is sensible to overspeed, operates as follows: the push-rod 3 overcomes the action of the spring 3' and causes the lever 4 to pivot by overcoming the action of the return spring 4'.

The slide valve 5' is then pushed to the right (in FIG. 1) by the return spring 5", so that the pressurized-fluid intake valve 50 is opened and the two conduits 6 and 6 are interconnected. The pressurized fluid, such as for instance compressed air or pressurized oil, arrives through the conduit 6 in the direction indicated by the arrow in FIG. 1, flows through the conduit 6 and is supplied to the four pneumatic or hydraulic actuators 2 which act upon the pistons of the respective fuelinjection pumps 1, thus stopping the supply of fuel in the associated pumps 1, independently of the toothed rack 7 and according to a process which will be described later.

When the fuel supply is to be resumed, the draw-slide 5b is pulled manually to reset the tripping means 5. The lever 4 returns to its initial position (shown in FIG. 1) under the action of the spring 4, the spring 3' returns the rod 3, and the conduits 6' and 6" are again interconnected.

It is readily understood that owing to this principle, even if the toothed rack 7 is casually jammed, the injection of fuel is stopped in the pumps 1 by a direct and individual action upon each actuator 2 regardless of the positions of the racks. The details concerning the emergency stopping device controlling the pistons of the fuel-injection pumps 1 and the operating principle of the said device will be described with reference to FIGS. 2, 3, 4 and 5.

FIG. 2 shows a pneumatic or hydraulic actuator 2 mounted on a pump shown partially and indicated generally by the reference digit 1. The actuator 2 is a pneumatic or hydraulic actuator of a type known per se, comprising a piston 11, a piston rod 12, a seal 13 and a cylinder 14. The actuator 2 is mounted on a lateral orifice 15 permitting the access, for instance, to the system of regulation of the injection stroke of the pump 1. The pump 1 is a fuel-injection pump of a conventional type and, consequently, only the novel and advantageous elements provided by the invention will be considered in the following description, without describing the mounting details already known in the art. At the junction of the pump 1 and the pneumatic or hydraulic actuator 2, at the level of the orifice 15, is mounted a lever 16 provided with two forks 18, 19 and adapted to pivot on its fulcrum 17. The end of the fork 18 of the pivotable lever 16 is located between the tappet 29 and the guide 20 of the piston (not shown) of the pump 1. The lever 16 is retained in its central portion by a yoke 22 solid with the cylinder 14 (see FIGS. 3 and 4).

Moreover, a lever 21 provided on the actuator 2 permits manual actuation, through the medium of the stopping device, of the piston of the associated injection pump 1 in order to prime the latter. The lever 21 is pivotallymounted on a pin 25 of the link 24 hinged at 25 to the member 23 engaging the upper portion of the cylinder 14 of pneumatic or hydraulic actuator 2. The lever 21 also acts as an emergency hand control lever which permits manual actuation of the piston 11 of the actuator 2 in order to cut off the connection between the piston of the pump 1 and its actuating mechanism, in case of a failure of the tripping means 5.

Although the pneumatic or hydraulic actuator 2 is shown as being advantageously mounted on the pump 1 at the level of the opening 15, it is readily understood that it may be mounted at another point on thepump, the arrangement being so designed as to enable the fork 18 of the pivotable lever 16 to come into contact with the portion -26 (FIG. 2) of the guide of the piston 20 of the pump 1, so as to raise the latter as will be described herein under. In order to illustrate the foregoing general description of the mechanical elements of the emergency stopping device, the operation of the latter in case of engine overspeed will now be explained.

As explained with reference to FIG. 1, in case of overspeed the centrifugal-action tripping means controls all the actuators 2. This control consists in opening the pressurized-fluid intake valve 5a, the said fluid being thus supplied to the hydraulic actuators 2 associated, respe'ctively,,with the pumps 1, by being conveyed by each conduit 27 (FIG. 2) into the associated actuator. In each actuator the pressurized fluid pushes the piston of the actuator 11 downwardly until the latter, occupies the position shown in dotted lines in FIG. 2. In moving vertically downward the piston 11 acts upon the pivotable lever 16 through the medium of the fork 19. More specifically, the left arm (in FIG. 2) of the lever 16 is lowered to a lower position (shown in dotted lines in FIG. 2), whereas the right arm of the lever and, therefore, the fork 18 of the lever 16 is raised,

prising the tappet 29 and a cam (not shown). Thus, th supply of fuel is completely stopped.

The assembly formed by the lever 21 and its supporting elements 24, 25, 25 is a removable assembly which is adapted, by a lateral or transverse motion, onto the cylinder head of each actuator 2, where it is retained by being keyed under the flange of a projecting portion 14a integral with the cylinder head. Thus, a single such assembly can be used successively for all the actuators 2.

The invention is applicable more particularly to the internal combustion engines of automotive vehicles and ships.

Of course, the invention is by no means limited to the forms of embodiment described and illustrated, which have been given by way of example only. In particular, it comprises all the means constituting technical equivalents to the means described as well as their combinations, should the latter be carried out according to the spirit of the invention.

What is claimed is:

1. In an internal combustion engine of the fuelinjection type fed with fuel by injection pumps, each of which comprises a piston operated by an actuating mechanism releasably connected thereto, an emergency stopping arrangement comprising tripping means adapted to supply servo-motors with pressure fluid in case of overspeed of the engine, each of said servemotors being associated with one of said-pumps and comprising a piston-type actuator mounted on the associated injection pump, and a lever connected, on the one hand, to the piston of said pump and, on the other hand, to the piston of said actuator and pivotally mounted between its two ends on a stationary fulcrum point.

2. An arrangement according to claim 1, wherein each pump is formed with a lateral orifice giving access at least to the operative connection between its piston and associated actuating mechanism and each one of said actuators is mounted on said lateral orifice for releasably engaging said connection.

3. An arrangement according to claim 1, wherein each one of said actuators comprises a manual control lever for operating same.

1 a: :r a

Claims (3)

1. In an internal combustion engine of the fuel-injection type fed with fuel by injection pumps, each of which comprises a piston operated by an actuating mechanism releasably connected thereto, an emergency stopping arrangement comprising tripping means adapted to supply servo-motors with pressure fluid in case of overspeed of the engine, each of said serve-motors being associated with one of said pumps and comprising a piston-type actuator mounted on the associated injection pump, and a lever connected, on the one hand, to the piston of said pump and, on the other hand, to the piston of said actuator and pivotally mounted between its two ends on a stationary fulcrum point.

2. An arrangement according to claim 1, wherein each pump is formed with a lateral orifice giving access at least to the operative connection between its piston and associated actuating mechanism and each one of said actuators is mounted on said lateral orifice for releasably engaging said connection.

3. An arrangement according to claim 1, wherein each one of said actuators comprises a manual control lever for operating same.

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