JPH04136475A - High pressure oil generator for internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate the power loss by matching the oil feeding quantity of a working oil pump with the used quantity of oil by utilizing a jerkey type fuel injection pump as high pressure pump and obviating the need of the complete stop of an engine even if a part of the pumps are broken, by using a plurality of fuel injection pumps. CONSTITUTION:A plurality of high pressure pumps 9 are arranged in radial form, keeping a prescribed pitch theta, and each pump rack 9a is connected, and one edge is joined with an actuator 15. The discharge quantity of each high pressure pump 9 is controlled through feedback so that the pressure of a collection pipe 17 becomes a set value. Accordingly, a controller 16 compares the set pressure with the detected pressure in the collection pipe 17, and one edge of the rack 9a is controlled through the actuator 15 so that the deviation becomes zero. Accordingly, the high pressure pump 9 supplies the working oil corresponding to the consumption quantity, and the driving loss of the high pressure pump 9 is little. Further, even if one pump is sticked, the supply of high pressure oil can be continued if other pumps are in normal operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-pressure oil generator for hydraulically driving exhaust valves and the like of an internal combustion engine.

[Conventional technology]

An example of a conventional high-pressure oil generating device for driving a valve is the one described in Japanese Patent Application No. 58-46925.

This device consists of a hydraulic oil supply pump, a filter, a hydraulic oil tank pressure regulating valve, and an accumulator. The hydraulic oil supply pump is driven by the engine via a belt.

[Problem to be solved by the invention]

However, the above-mentioned conventional high-pressure oil generator has the disadvantage that no measures are taken in the event of a failure of the hydraulic oil supply pump or consideration is given to reducing the driving force. In other words, in the former case, there is only one hydraulic oil supply pump, so if the piston and cylinder of the pump stick, the hydraulic oil supply will stop, making it impossible to operate the equipment driven by the hydraulic oil, and eventually stopping the engine. Regarding the latter, the hydraulic oil supply pump always discharges more hydraulic oil than the consumption of the high-pressure oil system, and the hydraulic oil pressure is controlled by a pressure regulating valve, so the hydraulic oil The driving force of the supply pump is greater than the required amount, resulting in large power loss. Furthermore, as a measure against fluctuations in hydraulic fluid discharge pressure, only the accumulator is used, and no consideration is given to the supply pump.

The purpose of the present invention is to solve the problems of the conventional device, and to provide high-pressure oil for an internal combustion engine with a pump configuration that eliminates power loss and reduces oil pressure fluctuations because the amount of oil supplied by the hydraulic oil pump can reliably match the amount used. To provide the generator.

[Means to solve the problem]

A high-pressure oil generator for an internal combustion engine according to the present invention includes: a cam having one or more lobes integrally fixed to a crankshaft; one or more jerk-type high-pressure pumps operated by the cam; a hydraulic oil source that supplies hydraulic oil to the pump;
The controller includes a collecting pipe for high-pressure hydraulic oil discharged from each of the high-pressure pumps, and a controller that detects the hydraulic oil pressure in the collecting pipe and changes the rank position of each high-pressure pump based on the deviation from a predetermined pressure. It is characterized by Note that the high-pressure pumps may be provided at equal intervals around the cam or may be arranged at non-equal intervals.

[For production]

The high-pressure oil injection device of the present invention utilizes a jerk-type fuel injection pump, which has been sufficiently used as a high-pressure pump, and uses multiple such pumps, so even if one plunger and barrel become stuck, other With this pump, it is possible to replace a stuck high-pressure pump and restore the original condition without stopping the supply of hydraulic oil, so there is no need to completely stop the engine even if some of the pumps fail.

The rotation of hydraulic fluid discharged in one rotation from a high-pressure pump is expressed as the product of the number of high-pressure pumps and the number of lobes on the cam. By setting the optimum pitch for the number of lobes, the discharge interval is made equal, and in engines with a small number of cylinders, the number of high-pressure pumps is reduced, and by thinning out the related pumps, fluctuations in discharge hydraulic pressure are reduced. , the volume of the collecting pipe can be reduced. Furthermore, the hydraulic pressure in the collecting pipe is detected and the discharge amount of the high-pressure pump is controlled via the bomb rack based on the deviation from the predetermined pressure, so that the amount of hydraulic fluid commensurate with the consumption amount is discharged, so the high-pressure pump is driven. This has the advantage of reducing force loss.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

Figure 1 is a configuration diagram of the rear end of the engine, and is a sectional view taken along line A-A in Figure 2.
FIG. 2(a) is a view in the direction of arrow C in FIG. 1, and FIG. 2(b) is a sectional view taken along line BB, showing the overall configuration of the high-pressure oil generator.

In the figure, numeral 1 indicates the crankshaft, 2 indicates a thrust collar integrated with the crankshaft l, 3 indicates a plurality of thrust pads that receive the thrust collar 2 and form a thrust bearing for forward and backward movement, and 4
A cam is divided into two parts and has a plurality of lobes 4a integrally bolted to the outer periphery of the thrust collar 2 via a key 5, and 6 is a journal bearing for receiving the crankshaft 1. 7
9 is a high-pressure pump bolted to the mount 7 via a pump holder 10, and 11 is rotatably attached to a sliding portion 13 via a bottle 12. The roller and sliding portion 13 are attached to the mounting base 7 and pump pedestal 10.
The upper end is in contact with the plunge portion of the high pressure pump 9.

The spring 14 presses the roller 11 against the cam 4 via the slide 13 and the pin 12. A plurality of high-pressure pumps 9- are arranged radially at a pitch θ, and each high-pressure pump 9 has a pump rack 9a.
are connected and one end thereof is coupled to the actuator 15,
The discharge amounts of these high-pressure pumps are controlled by the controller 16 through feedback so that the pressure in the collecting pipe 17 becomes a set value. The high-pressure pump 9 indicated by a broken line in FIG. 1 shows the case where the number of pumps is reduced in an engine with a small number of cylinders, and is shielded by a lid 18. The high-pressure pump 9 has a low-pressure oil inlet/outlet 19 , and low-pressure oil is supplied from a tank 20 via a filter 21 by an oil pump 22 driven by an electric motor, circulates through the high-pressure pump, and is regulated by a pressure regulating valve 23 . A spare filter 21 and oil pump 22 are provided in case of emergency.

FIG. 3 shows a sectional view of a jerk type high pressure pump. A plunger 30 is slidably guided in a plunger barrel 30 having an oil supply hole 32a fixed to a main body 31. The lower part of the plunger 30 is pressed against the sliding part 13 by a spring 33, and is moved up and down by the cam 4, and the plunger 30 is rotated through the sleeve 34 by the bomb rack 9a, changing the position of the lead 35 and starting the high pressure pump 9. Controls the discharge amount. At the top of the barrel 32 is a presser foot 3.
It has a discharge valve 38 which is tightened with a bolt 39 via 6 and pressed downward by a spring 37, and 40 indicates a high pressure oil discharge port.

Next, the operation of this embodiment will be explained.

Since a plurality of high-pressure pumps 9 are installed, even if one pump sticks, the supply of high-pressure oil continues as long as the other pumps are normal, and the high-pressure pumps can be repaired or restored without stopping the engine. The number of discharges Y of the high-pressure pump 9 per engine revolution is expressed by the product of the number N of plungers of the high-pressure pump 9 and the number Z of lobes of the cam 4 by the following equation.

Y=NXZ...(1) Also, the pressure fluctuation rate Δp of high pressure oil caused by the discharge of hydraulic oil is determined by the discharge flow fluctuation rate Δq, where Δq is the number of discharges Y
is expressed as shown in FIG. FIG. 4 shows the case where the fluid is discharged at equal intervals, and the pressure fluctuation is minimized in the case of equal intervals.

Next, an example of equidistant approximation in the present invention will be explained with reference to FIG. The upper diagram in FIG. 5 is a high-pressure pump arrangement diagram showing the relationship between the 40-book cam 4 and the plurality of rollers 11, and the lower diagram shows the high-pressure pump discharge interval in this combination.

When the relationship between the number of lobes -Z of the cam, the number N of high-pressure pumps, and the pump arrangement θ is expressed by the following equation, the discharge will be at equal intervals.

Figure 5 (a) shows the case of an 8-cylinder engine, (b) shows the case of a 6-cylinder engine, and (C) shows the case of a 4-cylinder engine. is reduced, so the number of high-pressure pumps is eliminated, and the discharge interval is θ in (a), θ, 2θ, and
In (C), it is 2θ, and (a) and (C) can be equally spaced.

Furthermore, the controller 16 compares the set pressure with the detected pressure in the collecting pipe 17 and controls one end of the rack 9a via the actinator 15 so that the deviation becomes O. This will supply hydraulic oil commensurate with the amount consumed, reducing drive loss for the high-pressure pump.

〔Effect of the invention〕

Since the present invention is configured as described above, there is no driving loss of the high pressure pump, and there is little variation in the discharge pressure of the high pressure pump.
The volume of the collecting pipe can be reduced, and since multiple high-pressure pumps are installed, safety is high and interruptions in the supply of hydraulic oil can be prevented.

[Brief explanation of the drawing]

Figures 1 to 5 are configuration diagrams of the rear end of the engine in an embodiment of the present invention.
2(a) is a sectional view taken along arrow C in FIG. FIG. 5 is an explanatory diagram of pressure fluctuation, and FIG. 5 is an explanatory diagram of pump arrangement and discharge interval. DESCRIPTION OF SYMBOLS 1... Crankshaft, 4... Lobe, 9... High pressure pump, 16... Controller, 17... Collection pipe, 2
0.2122... Hydraulic oil source, 23... Pressure regulating valve. l-8 Fig. 2 Fig. Number of discharges Y Fig.

Claims (2)

[Claims] (1) A cam having one or more lobes that is integrally fixed to the crankshaft, one or more jerk-type high-pressure pumps operated by the cam, and a hydraulic oil source that supplies hydraulic oil to the high-pressure pumps. and a collecting pipe for high-pressure hydraulic oil discharged from each of the high-pressure pumps, and a controller that detects the hydraulic oil pressure in the collecting pipe and changes the rack position of each high-pressure pump based on the deviation from a predetermined pressure. High pressure oil generator for internal combustion engines. (2) The high-pressure oil generating device for an internal combustion engine according to claim 1, wherein the high-pressure pump is provided at equal intervals around the cam.