JPH021970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a warm-up method and apparatus for a hydraulic fuel injection timing adjustment device used with a fuel injection pump for a diesel engine.

(Prior Art) A known spring-flyweight timer used with an in-line injection pump for a diesel engine controls the injection timing of the injection pump according to the rotational speed of the engine. With the timer, it was not possible to control the engine so as to sufficiently satisfy exhaust gas regulations and keep the fuel consumption rate low. For this reason, recent efforts have been made to develop an electronically controlled hydraulic timer that can freely change the fuel injection timing using an external control signal.

(Problem to be solved by the invention) However, since this electronically controlled hydraulic timer uses a hydraulic actuator as an actuator to create a rotational phase difference between it and the input shaft, it cannot be activated at the start of operation in extremely cold regions. There was a risk that the oil viscosity would increase, making it impossible to accurately adjust the fuel injection timing at the start of operation. Since the electronically controlled hydraulic timer is originally adopted for precision control operations, such a decrease in control characteristics at the start of cold operation is not desirable. That is,
Deterioration in operation at the start of operation is contrary to the original aim, and is one of the important issues that must be resolved.

SUMMARY OF THE INVENTION An object of the present invention is to provide a warm-up method and apparatus for an electronically controlled hydraulic timer that can solve the above-mentioned problems and improve the characteristics of the electronically controlled hydraulic timer at the time of starting operation.

(Means for Solving the Problems) The present invention is characterized in that the coil of the solenoid valve is used as a heater coil when the engine is stopped prior to starting operation of the engine. A large current different from that used during control is passed through the coil to generate heat, and the radiation and conduction of this heat is used to heat the hydraulic oil.

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

FIG. 1 is a conceptual longitudinal sectional view showing an example of an electronically controlled hydraulic timer to which the present invention is applied. In the figure, 1 is a casing, 2 is an input shaft, 3 is an output shaft, 4 is an intermediate shaft, and 5 is a cylindrical piston that supports the intermediate shaft 4 and is movable in the axial direction. is a cylinder 6 that houses the piston 5
is formed. The input shaft 2 is generally rotationally driven by an injection pump gear of an internal combustion engine, and is rotatably supported by a bearing B at the front end of the casing 1. On the other hand, the output shaft 3 is generally connected to a fuel injection pump shaft, and is rotatably supported by a bearing B at the rear end of the casing 1. Portions of the input shaft 2 and output shaft 3 extending into the casing 1 are each formed into a cylindrical body, and helical splines 2a and 3a are formed on the inner peripheral surfaces of the cylindrical body portions 2A and 3A.

An intermediate shaft 4, which is rotatably supported by a bearing B within the piston 5, protrudes from within the piston 5 in the front-rear direction, and has a helical spline 4a meshed with the helical splines 2a and 3a at each end. and 4b.
It has B. Therefore, it will be understood that when the piston 5 is moved in the left-right direction, that is, in the axial direction in FIG. 1, a rotational phase difference occurs between the input shaft 2 and the output shaft 3.

The piston 5 and cylinder 6 constitute a hydraulic actuator of this electronically controlled hydraulic timer. A solenoid valve 8 is attached to the outer surface of the casing 1 as an actuator control unit for controlling the amount of movement of the piston 5, and ports 7a and 7b communicating with the ports of the solenoid valve 8 are provided in the cylinder 6.

The electromagnetic valve 8 is a well-known one, and as shown in FIG. 2, it has a spool 8b housed in a valve body 8a so as to be movable in the axial direction, and cores 8c integrally provided at both ends of the spool 8b.
and a coil 8d provided adjacent to the valve body 8a surrounding the core 8c. Note that 8e is the lower spring of the spool 8b.

A control signal is sent to the coil 8d of the solenoid valve 8 from the electronic operation control device 9 during engine operation, and the core 8
By moving the spool 8b left and right, the spool 8b integrated with the spool 8b is displaced, and the hydraulic pressure is transferred to the port 7 in Fig. 1.
a or 7b. During this steady operation, a relatively low current is supplied to the coil 8d as long as it is sufficient to move the spool 8b.

In the present invention, when the engine is stopped, the coil 8
A large current is supplied to the coil 8d, and the heat generated from the coil 8d is used to heat the electronically controlled hydraulic timer device itself,
Alternatively, the oil piping system and the oil itself can be heated using heat radiation or conduction from the coil 8d, thereby improving the characteristics of the engine at the start of operation.

That is, the main switch 10 has a warm-up terminal 10a,
It has at least three stages, a steady operation terminal 10b and a starting terminal 10c, and when the main switch 10 is set to the warm-up terminal 10a, the battery 11 communicates with the coil 8d. At this time, the circuit of the electronic operation control device 9 may be cut off via the relay 12.

The steady operation terminal 10b of the main switch 10 supplies power to a steady operation system (not shown), and the starting terminal 10c
is connected to the starter motor M at the same time as the steady operation system.

Next, the operation of the present invention having the above structure will be explained.

Prior to starting the engine, the main switch 10 is first switched to the warm-up terminal 10a when the engine is stopped.
Then, the circuit of the electronic operation control device 9 is activated by the relay 12.
A current is passed through the coil 8d by a power supply system (not shown), and the coil 8d generates heat. Therefore, the solenoid valve 8 is heated by the heat. The solenoid valve 8 is provided near the electronically controlled hydraulic timer, and the oil used for control operation is stored near the solenoid valve 8, so that the entire device and the oil receive heat radiation from the solenoid valve 8. or by heat conduction through the piping system. The oil also receives heat when it is sent to the electronically controlled hydraulic timer through the solenoid valve 8.

Therefore, the control characteristics of the electronically controlled hydraulic timer at the start of cold operation are improved, and an appropriate injection timing can be selected from the start of operation.

For heating, after power is supplied to the coil 8d for a predetermined time, the main switch 10 is brought into contact with the starting terminal 10c, and the engine is started by the starter motor m. In this state, the coil 8d of the solenoid valve 8 receives power from the electronic operation control device 9.

Next, the main switch 10 connects the steady operation terminal 1
0, and the engine enters steady operation. At this time as well, the coil 8d receives power from the electronic operation control device 9.

Note that the above is an embodiment of the present invention, and the present invention is applicable to heating the entire device and even the oil by using the heat generated by the coil of the solenoid valve when the engine is stopped before starting operation. It includes all embodiments thereof.

Although the voltage-controlled hydraulic timer to which the present invention is applied has a structure as shown in FIG. 1, the application of the present invention is not necessarily limited to that shown in FIG. 1977-
The present invention can also be applied to a fuel injection timing controller as shown in Japanese Patent No. 5493.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a main part of an embodiment of a hydraulic fuel injection timing adjustment device to which the present invention is applied, and FIG. 2 shows a solenoid valve provided in the hydraulic system of the device shown in FIG. FIG. 2 is a conceptual diagram of an embodiment of the device. 1: Casing, 2: Input shaft, 2A: Cylindrical part, 2a: Helical spline, 3: Output shaft, 3
A: Cylindrical part, 3a: Helical spline, 4:
Intermediate shaft, 4A: insertion part, 4B: insertion part, 4a: helical spline, 4b: helical spline,
5: Piston, 6: Cylinder, 7a: Port,
7b: port, 8: solenoid valve, 8a: valve body, 8b: spool, 8c: core, 8d: coil, 8e: positioning spring, 9: electronic operation control device, 10: main switch, 10a: warm-up terminal,
10b: Steady operation terminal, 10c: Starting terminal, 1
1: battery, 12: relay.

Claims (1)

[Scope of Claims] 1. A method for warming up a hydraulic fuel injection timing adjustment device having a solenoid valve that supplies oil to the hydraulic fuel injection timing adjustment device, wherein the coil of the solenoid valve is operated in a steady state when the engine is stopped. 1. A method for warming up a hydraulic fuel injection timing adjustment device, characterized in that the coil is made to generate heat by being supplied with power through a system different from the current power supply system. 2. A warm-up device for a hydraulic fuel injection timing adjustment device having a solenoid valve that supplies oil to the hydraulic fuel injection timing adjustment device, wherein the main switch is provided with at least a warm-up terminal and a steady operation terminal, and the main switch is provided with at least a warm-up terminal and a steady operation terminal. A warm-up device for a hydraulic fuel injection timing adjustment device, characterized in that one of the terminals is connected to a battery, and the other warm-up terminal is connected to a power supply system for a coil of a solenoid valve during steady operation.