DE3347533A1 - Hydraulically actuated gas exchange valves for internal combustion engines - Google Patents

Abstract

The invention proposes a system with hydraulically actuated gas exchange valves (intake and exhaust valves) which has a pump, a rotary distributor and a working piston with travel-dependent positive control. With high acceleration and corresponding deceleration of the gas exchange valves, the opening cross-section during the various cycles is thereby increased in comparison with cam control systems, the overlap between the intake and exhaust valve, which entails losses, is avoided and charging and additional charging are increased. In a further development of the inventive concept, the control programme stored in the rotary distributor can be influenced, in particular, by magnetic valves, the speed-dependent additional charging thereby being optimised in accordance with the prevailing engine speed and, in the case of Otto engines, the throttle valve can be dispensed with. An increase in the power of the internal combustion engine is achieved.

Description

H.E. 12/15/83

Dipl.-Ing. Helmut ESPENSCHIED UDE, Turmstr. 8, 71U0 Ludwigsburg

State of the art

The invention relates to a hydraulic system for actuating the Gas exchange valves in internal combustion engines according to the genus Main claim.

The mechanical actuation of the gear change valves by cam control is predominant in internal combustion engines. Other mechanical solutions, such as slide controls, could not prevail.

Various other systems were used to control the gas exchange valves proposed, in particular with the aid of hydraulics.

With the aid of hydraulics as a possibility of intervening in a rigid valve control program, DE - AS Zk kB 311, DE - OS 30 kB BBl, DE - OS 31 35 650 versions were known in which the cam was retained and a hydraulic encoder and The taker principle is applied.

Another principle with the aid of hydraulics was introduced with DE - PS 2G08668 known in which the control of each individual gas exchange valve with With the help of a solenoid valve.

DE-OS 28 Ik 863 specifies an embodiment in which several control rollers, with the possibility of longitudinal adjustment, controlled hydraulic actuation of actuators and gas exchange valves can take place.

Advantages of the invention

The embodiment of the hydraulic system according to the invention for actuating the gas exchange valves assumes that with the help of the hydraulic force, conversions in longitudinal movements are possible much faster than with cam drives can be done.

To reduce the hydraulic time constants, large, short line cross-sections are provided, as well as sudden diversions and blocks of the hydraulic flow should be avoided. The hydraulic force is provided directly on the actuating piston. The moving mass of the gas exchange valve and Actuating pistons are reduced to a minimum and the actuating forces can largely be matched to the forces to be overcome.

The access control on the actuating piston helps reduce the hydraulic Time constants at and enables the optimal acceleration and deceleration of the gas exchange valve actuation while avoiding mechanical ones and hydraulic strokes.

With the rotary distributor a technical-economical solution is given, the ühne gap losses, precisely with the dimensions of the control edges not too small, works with low friction with hydrostatic bearings.

The rotary distributor has an embossed program that is suitable for many applications, for both the inlet and outlet valves, in Dtto and diesel engines Degree of filling and gas exchange improved.

Intervention in the programmed program after or via the rotary distributor preferably by means of solenoid valves in a bypass circuit is a further idea of the invention.

There are very fast switching valves for an application after the rotary distributor in piezD electrical design for the necessary pressures and response times. When switching via the rotary distributor, the number of switching valves can be up to can be reduced to one.

Solenoid valve designs with a fast diaphragm according to DE - QS 32 11 6BO of the applicant and according to the subclaims of this application are required in high-speed internal combustion engines.

By quickly opening and closing the gas exchange valves, the The valve overlap practiced today can be largely dispensed with. In order to you get clean exhaust gas and save fuel.

The reloading effect caused by later closing of the inlet valve cannot be waived. The reloading effect is speed-dependent and can be used without intervention only be optimal for a certain speed. The intervention with help the aforementioned fast solenoid valves creates the possibility of optimizing the reloading effect at different speeds. The one mentioned Intervention represents charge control in a broader sense and makes the throttle valve superfluous in gasoline engines.

This means that the electronics of a gasoline injection with the Fill control can be combined and a wide range of motor controls and engine interventions can be solved in a very simple way.

The person skilled in the art recognizes that interventions with less rapid solenoid valves are possible with the help of the rotary distributor. The opening or closing of the common outer bores in the rotary distributor already results in 2 stages for the Reloading effect or there can be freewheeling and braking effects when rolling Thrust can be generated by gas exchange valves that are open or throttled on all sides.

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This is particularly interesting for diesel engines without electronics, since the technical Effort is low and the throttle valve control is not required.

The economic advantage of the invention lies in the resulting larger charging using simple means. With the larger open inlet and outlet cross-section, according to the Design with a 50% higher load and thus power can be expected.

The following advantages arise:

No backlash compensation, compact design, free drive.

Drawings

An embodiment of the invention is shown in the drawings.

Fig. 1 shows the hydraulic actuation of the gas exchange valve with the stroke-dependent Constructive control override.

Fig. 2 shows a section through the built-in throttle points of Fig.

Fig. 3 shows the hydraulic pump, the rotary distributor, as assembled elements and the fast 2-stage 2/2 solenoid valve in a more constructive manner Execution.

Fig. H shows the right development of the channel guide of the rotary distributor. (The left-hand development of the canal guide can be a mirror image).

Fig. 5 shows the hydraulic circuit diagram with the fast 2-stage 2/2 solenoid valve in the scheme.

Fig. G shows the open cross section on the ordinate and the abscissa the control angle of the crankshaft.

The curves show the current state with that achieved by the invention aimed at.

Description of the execution example

The hydraulic system consists of a feed pump 1, a rotary distributor 9, a working piston 3, a 2-stage 2/2 solenoid valve 17, a pressure relief valve with pressure accumulator 6, throttle point 21, check valve 22, a hydraulic tank 2 and a hydraulic filter 23.

The feed pump 1 and the rotary distributor 9 are running at half the crankshaft speed synchronously driven.

Don Drehvertciler 9 (at 4-cyl motors) for the k innenlisqenden, connected in parallel and fixed bores 26, the hydraulic pressure

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fed. From there the branch takes place once to the circulating Uteilerbahn 24 and on the short-circuited pressure compensation surfaces 25. As soon as sine ϊππεγε bore 26 with a central bore 27 won the circumferential Manifold track 24 is cut and there is passage to the associated one Working piston 3.

A passage to the 4 parallel-connected 4 outer holes is delayed 28 came about so that time to activate the solenoid valve 17 gained that is available, as it is not switched on and off at the same time luerdEn must.

The outer bores 28 lead via line 38 to the 2-stage solenoid valve 17, which is aroused when closed.

In this state, the right membrane 29 of the magnet valve 17 becomes magnetic pressed onto the pole 3G, which is at the same time a nozzle and closing element. The drain to container 2 is blocked. It builds up in the left membrane 31 in front of and behind the same pressure. Since the area in front of the membrane 31 is smaller than then, the membrane 31 is pressed onto the drainage opening 32. As soon as the excitation 20 of the solenoid valve 17 is interrupted, the right one becomes Membrane 29 pushed open by the system pressure and discharged via the nozzle on the right 33 and 2 nozzles on the left 34. Since the nozzle on the right 33 in cross section is essential is larger than the 2 nozzles left 34 together, the pressure on the right breaks Membrane side together, whereas the pressure on the left side of membrane 31 remains the same. The large opening 32 is released and the pressure in the line 35, 38 goes to zero.

The inner path 36 with the hydraulic supply line 26 is up to half of the Cycle still with a throttled cross-section to compensate for leakage currents connected to the outer path 37 and interferes with when the excitation is switched off 20 the rapid drainage via the solenoid valve 17 hardly. In the 2nd half of the Inlet 26 is completely separated from the cycle. The two pre-tensioned membranes 29, 31 return to their starting position and after the hydraulic pressure has subsided are ready for the next cycle.

If the excitation 2ü of the solenoid valve 17 is not interrupted, then takes place the emptying of the lines 35 at the end of the cycle via the central path 39, ring channel 40 to the container 2.

The outflow via the middle lane 39 remains for those who are not in use Gas exchange valves for diverting leakage currents of up to about a half Receive cycle before use. The leakage current then serves to ensure that line 35 is under increased pressure before use. The lines 35 to the working caliper have to quickly open the

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Gas exchange valve free passage in the check valve 22. The first stage the stroke-dependent forced control 41 goes into the 2nd stage 42 without any change of hydraulic flow over. The 2nd level 42 interrupts when the End position 45 the hydraulic flow itself. On the opposite side is in the first stage 43 the pressure is lowered by throttled inlet and outlet and In the 2nd stage 44, the wool counterpressure 46 is applied. With the stroke-dependent If the hydraulic flow on the supply side 42 is interrupted, the working piston 3 is braked.

The gas exchange valve 7 is closed by opening the supply lines The stepped piston via the inlet 44 is pressurized with full system pressure. This is followed by the stage with reduced system pressure through the two throttles 4, above the inlet 43. On the opposite side, the inlet 43 is used for braking the throttle 21 becomes effective and the gas exchange valve closes fully 7th

Further information can be found in the hydraulic circuit diagram.

The hydraulic circuit diagram Fig. 5 shows the rotary distributor side 12 with a Solenoid valve 17 is preferred for the inlet valves. For the exhaust valve actuation an analog rotary distributor side 13 is required, which is already shown in FIG. 3. Since there is usually no intervention in the exhaust valve actuation is, a further solenoid valve 17 can be omitted and thus also the outer bores 2ß not required.

6 shows the diagram of the open cross sections of the gas exchange valves 7 via the control angle of the crankshaft.

The -.-.- = line 5G and the -..-..- = line 51 show the relationships at a cam control.

The —c ^ ~ - = line 47 and the = line 48 show the relationships at

the hydraulic actuation without intervention, the - - - - = lines 49 show Examples of a possible intervention.

Fig. 1 to 4 also show constructive training options.

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Claims (15)

H.E. 12/15/83 Dipl.-Ing. Helmut E5PEIM5CHIED WDE, Turmstr. B, 71 ^ 0 Ludujigsburg Claims Λ.) Hydraulically operated gas exchange valves for internal combustion engines in a hydraulic system with a pump, a control-programmed rotary distributor and a working piston, characterized in that the Working piston (3) has a stroke-dependent positive control. 5 2. Hydraulically operated gas exchange valve for internal combustion engines according to claim 1, characterized in that the working ram (3) is stepped is executed doppeluirkend. 1D 3. Hydraulically operated gas exchange valve for internal combustion engines according to one or both of claims 1 and 2, characterized in that hydraulic means (k, 5) are used for the amplifying movement of the working cylinder (3) and for braking (Mt) towards the end of the movement will.
15th 4. Hydraulically operated gas exchange valves for internal combustion engines according to one or more of claims 1 to 3, characterized in that hydraulic means are used to lower the pressure (4, 5), the enable constant flushing of the working piston (3) at the same time. 5. Hydraulically operated gas exchange valves for internal combustion engines according to one or more of claims 1 to h, characterized in that one side of the working piston (3) operates alternately as a pump for energy recovery. 6. Hydraulically operated gas exchange valves for internal combustion engines according to one or more of claims 1 to 5, characterized in that the pressure reduction valve (6) is designed at the same time as a reservoir is. 3D 7. Hydraulically operated gas exchange valves for internal combustion engines according to one or more of claims 1 to 6, characterized in that that working piston (3) and gas exchange valve (7) are positively connected by snap lock (B) and separated again by being pressed out can be. B. Hydraulically operated gas exchange valves for internal combustion engines according to one or more of claims 1 to 7, characterized in that that the rotary distributor (9) with different programs (1 * 0, in particular can be carried out between inlet and outlet valves. 5 9. Hydraulically operated gas exchange valve for internal combustion engines according to claim B, characterized in that the rotary distributor (9) Paths for a control program (14) with unimpeded (15) and throttled (16) Has flow. 1D. Hydraulically operated gas exchange valve for internal combustion engines according to one or more of claims 1 to B, characterized in that that the rotary distributor (9) is mounted hydrostatically (24) with pressure surface compensation (25). 11. Hydraulically operated gas exchange valve for internal combustion engines according to one or more of claims 1 to 10, characterized in that that the rotary distributor (9) consists of 2 conical parts (12, 13), which allow a gap-free operation and their hydrostatic pressure vorzugueise caught by a spring (21), which also acts as a protection against bursting can offer. 12. Hydraulically operated gas exchange valve for internal combustion engines according to one or more of claims 1 to 11, characterized in that that the control program (14) of the rotary distributor (9) can be intervened directly or indirectly by controllable valves. 13. Hydraulically operated gas exchange valves for internal combustion engines according to claim 12, characterized in that a variable control program in execution (10, 11) and the tracks (36, 39) in the rotary distributor (9) through one wire several valves by switching can be. 14. Hydraulically operated gas exchange valves for internal combustion engines according to one or more of claims 1 to 12, characterized in that in the control program (14) of the rotary distributor (9) by a valve (17) can be intervened continuously. -1 / 3- 15. Hydraulically operated gas exchange valve for internal combustion engines according to claim 13 vein 1 ^, characterized in that the valve (17) preferably designed in a 2-stage straight-through design (18, 19) and the electrical excitation (2Ü) for the closing vargang is on can limit a magnetic lock.