JPH0323729B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulically operated fuel injection timing adjustment device that can freely adjust fuel injection timing in response to external control signals.

(Prior Art) In order to always operate a vehicle-mounted internal combustion engine under optimal conditions depending on the vehicle's running conditions and exhaust gas conditions, it is necessary to freely control the amount and timing of fuel supply to the internal combustion engine. It is necessary to obtain it.

Conventionally, control of these two variables has already been implemented for gasoline engines for passenger cars, but it has not yet been implemented for diesel engines. The main reason for this is that the conventional spring-type flyweight timer installed in the fuel injection pump of a diesel engine cannot freely change the fuel supply timing.

However, with the development of research over the past few years, a new hydraulically actuated fuel injection timing adjustment device that can freely change the fuel injection timing has been developed in place of the conventional flyweight timer. The prospect of being able to control it freely has been obtained.

An example of such a novel hydraulically operated fuel injection timing adjustment device is the device disclosed in Japanese Utility Model Application No. 55-36920. This new hydraulically operated fuel injection timing adjustment device adjusts the rotational phase difference between the input shaft connected to the crankshaft of a diesel engine and the output shaft connected to the fuel injection pump in response to an external control signal. A hydraulic actuator is used as the operating device to create a rotational phase difference between the input shaft and the output shaft.

In the known hydraulically operated fuel injection timing adjustment device, the hydraulic pump for operating the hydraulic actuator is connected to the input shaft of the fuel injection pump (the hydraulic actuator rotates integrally with the input shaft of the fuel injection pump). It was designed to be rotatably driven by a gear that was installed integrally with the engine and rotated by the diesel engine's crankshaft. This means that the rotation of the fuel injection pump is 1/2 the rotation of the crankshaft, so the rotation of the diesel engine's crankshaft is once reduced to 1/2 via the reduction mechanism, and this reduced rotation is used to reduce the rotation of the diesel engine's crankshaft to 1/2. The hydraulic pump was supposed to be rotated.

(Problems to be Solved by the Invention) As described above, when a hydraulic actuator is used as an operating device, the hydraulic circuit and hydraulic pump connected to the hydraulic actuator are miniaturized, lightweight, operational reliable, and operational economical. Gender, etc. must be fully considered. In particular, when equipping a vehicle-mounted diesel engine with the hydraulically actuated fuel injection timing adjustment device, if sufficient consideration is not given to these points, installation space, running economy,
There is a risk of failure in various aspects such as price, performance, and reliability.

In the above-mentioned conventionally known hydraulically operated fuel injection timing adjustment device, the rotation of the crankshaft of the diesel engine is once decelerated by half via the reduction mechanism, and this decelerated rotation is transmitted to the input of the fuel injection pump. Since the gear provided on the shaft is used to slightly increase the speed and drive the rotation, the rotational speed of the hydraulic pump is not that high, and especially when the diesel engine is operating at low speed, there is sufficient oil pressure or There was a risk that the amount of oil could not be obtained. To avoid this, you can install a large hydraulic pump, but installing a large hydraulic pump means that
This is unfavorable in terms of mounting space, running economy, and price.

The present invention has been made based on the above-mentioned reasons, and an object of the present invention is to provide a hydraulically actuated fuel injection timing system that can constantly supply high-pressure hydraulic oil to a hydraulic actuator and has an economical and compact drive system. The object of the present invention is to provide a regulating device.

(Means for Solving the Problems) The present invention is characterized by the following configuration.

That is, an input shaft, a hydraulic actuator rotationally driven by the input shaft, an output shaft that transmits the rotation of the hydraulic actuator to the outside, a fuel injection pump connected to the output shaft, and a hydraulic actuator connected to the hydraulic actuator. It consists of a hydraulic pump that supplies hydraulic oil and a control valve that controls the hydraulic oil that is supplied to the hydraulic actuator. In a hydraulically actuated fuel injection adjustment device that creates a rotational phase difference between a crankshaft of a diesel engine and an output shaft, the input shaft and the hydraulic pump are connected to separate drive shafts. transmits the rotation of the crankshaft of the diesel engine to the input shaft, and transmits the rotation of the crankshaft of the diesel engine to the hydraulic pump drive shaft via a speed increasing mechanism to hydraulically drive the rotary pump at a higher rotational speed than the input shaft. It's because I did it.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a hydraulically operated fuel injection timing adjustment device according to the present invention, and in the figure, 1 indicates the main body of the hydraulically operated fuel injection timing adjustment device. The main body 1 includes a first member 1 fixed to an input shaft 2.
01, and a second member 102 that engages with the first member 101 so as to be movable relative to the output shaft 3 and is integrated with the output shaft 3. A hydraulic actuator 103 is provided to create a rotational phase difference between the two. An injection pump drive gear 4 is attached to the tip of the input shaft 2, and the injection pump drive gear 4 is housed in a timing gear case 5 of a diesel engine.

On the other hand, a known fuel injection pump P is connected to the output shaft 3. A control valve 6 is connected directly or separately to the hydraulic actuator 103 , and a hydraulic pump 8 is connected to the control valve 6 via a hydraulic oil supply pipe 7 . hydraulic pump 8
A gear 10 having fewer teeth than the injection pump drive gear 4 is attached to the drive shaft 9 of the gear 1.
0 meshes with the crankshaft gear within the timing gear case 5 via a speed increasing mechanism such as another speed increasing gear train.

A hydraulic oil return pipe 11 connected to the control valve 6 and a suction pipe 12 connected to the hydraulic pump 8 are inserted into a hydraulic oil tank 13, and the hydraulic oil in the hydraulic oil tank 13 is supplied via the hydraulic pump 8. It is supplied to the control valve 6.

The control valve 6 is electrically connected to the control device 14,
It is operated by control signals from the control device 14.

FIG. 2 is a detailed longitudinal sectional view of the main body 1. In FIG. 2, a first member 101 is a cylindrical portion formed at one end of the input shaft 2;
01 and the input shaft 2 are connected to the casing 104 of the main body 1.
It is rotatably supported within by bearings 105 and 106. A cylinder 108 is accommodated inside the first member 101 , and a port 101 a that communicates with an oil groove 108 a on the outer peripheral surface of the cylinder 108 is bored in the wall surface of the first member 101 . A rotary oil joint 109 for supplying hydraulic oil to the port 101a is connected to the first member 101.
It is fitted on the outer peripheral surface of. Inside the cylinder 108 is the cylinder 108 and a rotating oil joint 1.
A cylindrical piston 110 that constitutes the hydraulic actuator 103 together with 09 is fitted, and a female helical spline 110A and a male helical spline 110B are formed on both the inner and outer peripheral surfaces of the other end of the piston 110, respectively. . Among these helical splines, the male helical spline 110B on the outer circumference meshes with the female helical spline 101A formed on the inner circumference of the first member 101, and the female helical spline 110A on the inner circumference
is engaged with a male helical spline formed on the output shaft 3, that is, the second member 102.

Therefore, in the above configuration, the piston 1
10 is moved in the axial direction, the first member 101 and the second member 102 are moved in the rotational direction, and as a result, the input shaft 2 and the output shaft 3 create a rotational phase difference during their rotation, and the diesel engine The rotating shaft of the fuel injection pump is adjusted to be either phase delayed or phase advanced relative to the engine crankshaft.

(Effect of the invention) In the configuration of the device of the present invention as shown in FIG.
Since the hydraulic pump is rotated by a drive shaft separate from the main body 1 and at a higher speed than the main body 1, the hydraulic pressure supplied to the hydraulic actuator 103 can be maintained at a high pressure even when the diesel engine is operating at low speed. It has the advantage of being possible.

Such a configuration is particularly suitable for a vehicle diesel engine in which the rotational speed of the diesel engine is large and frequently fluctuates, and furthermore, the engine is frequently used at medium to low speeds.

Further, since many hydraulic pumps generally exhibit their highest efficiency in a high speed range, such a configuration also allows the hydraulic pump to be used efficiently and economically.

On the other hand, the above configuration does not require a special drive source to drive the hydraulic pump, so
According to the present invention, it is possible to obtain an economical hydraulically operated fuel injection timing adjustment device in which the hydraulic pump drive system is small and lightweight.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, and FIG.
The figure is a detailed longitudinal sectional view of a part of FIG. 1. 1: Main body, 2: Input shaft, 3: Output shaft, 101:
First member, 102: Second member, 103: Hydraulic actuator, 4: Injection pump drive gear, 5: Timing gear case, 6: Control valve, 7: Hydraulic oil supply pipe, 8: Hydraulic pump, 9: Drive shaft, 10 :gear,
11: Hydraulic oil return pipe, 13: Hydraulic oil tank, 1
4: Control device.

Claims (1)

[Claims] 1. An input shaft, a hydraulic actuator rotationally driven by the input shaft, an output shaft that transmits the rotation of the hydraulic actuator to the outside, and a fuel injection pump connected to the output shaft. , a hydraulic pump that supplies hydraulic oil to the hydraulic actuator, and a control valve that controls the hydraulic oil that is supplied to the hydraulic actuator, and the control valve is controlled by an external control signal to control the hydraulic actuator. In a hydraulically operated fuel injection device which is operated to produce a rotational phase difference between an input shaft and an output shaft, the diesel engine The rotation of the crankshaft of the engine is transmitted to the input shaft, and the rotation of the crankshaft of the diesel engine is transmitted to the hydraulic pump drive shaft via a speed increasing mechanism to drive the hydraulic pump at a higher rotation speed than the input shaft. A hydraulically operated fuel injection timing adjustment device characterized by being rotationally driven.