JPH04301148A - Device for adjusting the oil pressure in the control chamber of a reciprocating piston with compression height - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in particular to a device for adjusting the hydraulic pressure in the control chamber of a reciprocating piston with variable compression height of an internal combustion engine.

0002

BACKGROUND OF THE INVENTION Such a device is known from German Patent No. 37 14 762. In order to adjust the oil pressure, a solenoid valve located in the oil passage branching from the lubricating oil circuit and leading to the control room and a spool valve installed in the piston pin are required. This requires constructional effort and is hardly suitable for highly sensitive pressure regulation, especially at high rotational speeds of internal combustion engines.

0003

OBJECT AND SUMMARY OF THE INVENTION The object of the invention is therefore to provide a hydraulic adjustment which simplifies pressure regulation, reduces construction space and allows highly sensitive pressure regulation in all operating ranges. The purpose is to provide equipment.

0004

[Means for Solving the Problem] In order to solve this problem, according to the present invention, a hydraulic oil pump having a pressure regulating valve forms an adjustable pump device, and the oil pressure in the control chamber is set from this pump device. It is possible.

[0005]

[Effects of the Invention] The oil pressure in the control chamber is adjusted by using an adjustable pump device in the lubricating oil circuit of the internal combustion engine, and the pressure regulating valve integrated in the pump device is controlled electronically. Driven by a servo motor connected to the device. Such hydraulic regulation makes it possible to eliminate conventional solenoid valves with external opening and closing, as well as additional oil supply conduits and spool valves, thereby reducing construction space and reducing the number of conduits in the lubricating oil supply system. It becomes easy regarding. Additionally, the spool valve previously required in the reciprocating piston to control the oil supply conduit within the reciprocating piston is also avoided, which simplifies the construction of the reciprocating piston and reduces its weight, reducing moving mass. , quieter operation and bearing load are also improved.

With the device according to the invention, operating characteristic quantities such as load, engine speed, combustion chamber pressure, knock, cooling water temperature, component temperature and oil temperature of the internal combustion engine can be optimized over the entire characteristic curve range. Ru. This improves combustion efficiency, thereby reducing fuel consumption and pollutant emissions. Furthermore, fuel consumption, pollutant emissions and noise generation during cold starting and warm-up are improved. Moreover, the utilization of the internal combustion engine is increased, and therefore an advantageous weight per horsepower ratio is obtained. Furthermore, with the invention the regulating device reacts before unacceptable operating conditions occur, so that it is possible to avoid such conditions.

If, for example, in a gasoline engine one seeks to adjust the compression ratio for minimum fuel consumption, this means making the compression ratio as large as possible and thus close to the knock limit. The knock limit is detected by a knock sensor,
Compression ratio can be lowered in combustion with a knock. The disadvantage in this case is that only when combustion conditions with knocks occur,
It is possible to start the regulating device or piston. Knock combustion is a function of load, air and component temperature, air/fuel ratio, ignition angle, fuel quality, and rotational speed; therefore, knowing this relationship allows adjustment of the regulating device before knock combustion occurs. can react. Finally, a highly sensitive oil pressure regulation is also possible, since no control elements are required in the oil supply channel, which would impair the regulation characteristics.

[0008]

In a special embodiment according to claim 2, a vane pump is provided as the pumping device. A vane pump used as a lubricating oil pump in the lubricating oil circuit of an internal combustion engine is known from German Patent No. 3,333,647, but the prior art does not suggest the use of this pump for hydraulic regulation. do not have.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. A crankshaft 3 is supported in the partially shown crankcase 1 of the internal combustion engine 2, to which a connecting rod 4 with a reciprocating piston 5 of variable compression height is pivotally mounted. An oil passage 8 extends into the connecting rod 4 between its ends 6, 7 and opens into an oil supply conduit 9 at the large end 7 of the connecting rod. This oil supply line 9 leads to the discharge side 10 of a continuously adjustable vane pump 11, which is used as a lubricating oil pump in the lubricating oil circuit of an internal combustion engine. A suction conduit 14 emerges from the suction side 13 in the upper part 12 of the vane pump 11 , and its end 15 leads to an oil sump 16 in the crankcase 1 . On the discharge side, the vane pump 11 has an operating protrusion 18 on an eccentric wheel 17, and an adjusting plunger 19 of a pressure regulating valve 20.
It acts on Depending on the magnitude of the force acting on the operating protrusion 18, the adjusting plunger 19 of the pressure regulating valve 20 moves against the eccentric ring 17.
, thereby setting a specific oil pressure value on the discharge side 10 which is supplied via the oil supply conduit 9 to the control chamber 42 . Vane pump 11 therefore allows the hydraulic pressure in control chamber 42 to be adjusted in accordance with predetermined operating parameters of the internal combustion engine. For this purpose, the pressure regulating valve 20 is connected to the servo motor 21 via a control line 22, and the servo motor 21 is connected to the servo motor 21 via this control line.
moves the adjustment plunger 19. The magnitude of this movement is defined by an electronic control unit 23 connected to the servo motor 21 in relation to the operating parameters of the internal combustion engine. The operating parameters are detected by the sensors 24a-24h and transmitted to the electronic control unit 23 in the form of electrical signals. The electronic control unit 23 receives the load value of the diesel engine or the gasoline engine, for example via a sensor 24a, based on the amount of fuel injected from the injection pump 25 or the intake pipe negative pressure in the intake pipe 26. Furthermore, a sensor 2 is installed in the combustion chamber 27 of the internal combustion engine.
4b and 24c are provided to detect combustion chamber pressure and ion current. The housing 28 of the internal combustion engine has a sensor 2
4d and 24f are provided, with sensor 24d serving as a knock sensor and sensor 24f detecting member temperature. The temperature sensor 24e measures the temperature of the cooling water in the cylinder cooling passage 29, and the temperature of the oil is measured by the sensor 24h in the oil sump 16. Another measuring device, sensor 24g, is
The rotation speed of the crankshaft 3 is detected.

The reciprocating piston 5 consists of an outer piston 30, which is configured as a piston ring carrier, and an inner piston 31, which is accommodated in the outer piston 30 and forms the body 32 of the reciprocating piston 5 on the lower side. . Into the center hole 33 of the inner piston 31 is inserted a center protrusion 34 of a valve support plate 35 that rests fixedly on the inner piston 31 . A stop ring 37, which is fixedly screwed onto the lower edge 36 of the outer piston 30, together with an annular recess 40 provided in the lower side 38 of the outer piston 30 and the valve carrier plate 35 and in the upper region 39 of the inner piston 31, allows the lower oil to be removed. A space 41 forms a so-called braking chamber. An upper oil space 4 serving as a control chamber is formed by the upper side 43 of the valve carrier plate 35 and the inner wall 44 of the outer piston 30.
2 is partitioned. A throttle 45 and two check valves 46 and 47 are provided on the valve carrier plate 35, and the throttle 45 and the upper oil space 42 are connected to each other.
A check valve 46 , which closes toward the upper oil space 42 , connects the upper oil space 42 to the lower oil space 41 . The passage 48 leading to the check valve 47, which opens towards the upper oil space 42, leads to a bore 49 in the body 32 as an oil sump, the only bore opening 50 of which is closed off by a piston pin 51. There is. A further channel 52 serving as an oil return channel connects the upper oil space 42 with a pressure limiting valve 53 which is provided in the body 32 and has an opening 54 into the crank 1 . The passage 55 leading to the hole 49 is connected to an oil supply groove 56 in the small end 6 of the connecting rod 4 which leads to the oil passage 8.

The increase in compression height that occurs during the gas exchange phase is related to the inertial forces acting on the outer piston 30. This inertial force pulls on the outer piston 30, which causes a pressure increase in the lower oil space 41. Thereby the check valve 4
6 is closed. The increase in the compression height is determined by the adjustable oil flow from the lower oil space 41 to the upper oil space 42 via the throttle 45 . The increase in the upper oil space 42 is due to the increase in the upper oil space 42.
Additional oil flow from hole 49 occurs via check valve 47 at 8. the gas pressure transmitted from the air-fuel mixture ignited in the combustion chamber 27 to the upper oil space 42 opens the pressure limiting valve 53;
If the oil is allowed to flow into the crankcase 1, a reduction in the compression height takes place. At the same time, oil flows from the upper oil space 42 to the lower oil space 41 via the throttle 45 and check valve 46.
During the subsequent gas exchange phase, a force-transmitting connection between outer piston 30 and inner piston 31 is ensured.

[Brief explanation of drawings]

1 is a schematic diagram of an internal combustion engine with a regulating circuit showing in detail a reciprocating piston with variable compression height and a vane pump; FIG.

[Explanation of symbols]

2 Internal combustion engine 4 Connecting rod 5 Reciprocating piston 8 Oil passage 11 Lubricating oil pump 20 Pressure regulating valve 30 Outer piston 31 Inner piston 42 Control room

Claims (2)

[Claims] Claim 1: A control chamber for a reciprocating piston with variable compression height is formed between an inner piston connected to a connecting rod and an outer piston movably held on the inner piston, the control chamber being adapted for use in an internal combustion engine. The pressure regulating valve (20 control chamber of a reciprocating piston with variable compression height, characterized in that a lubricating oil pump with a regulator (42) forms a pumping device, from which the oil pressure in the control chamber (42) can be set. A device that adjusts the hydraulic pressure. 2. Device according to claim 1, characterized in that the pump device is a vane pump.