DE102017012085A1 - Device for controlling a pressure gradient level in a cylinder crankcase - Google Patents

Abstract

This device is used to control a pressure level in a cylinder crankcase of an internal combustion engine with at least one reciprocating piston, which is moved in a piston bore of the cylinder crankcase back and forth and is in operative connection with a crankshaft system of the internal combustion engine. To optimize the device causes this pressure and negative pressure influencing pressure curve and a mean pressure level in a crankcase of the cylinder crankcase, such that in the cylinder crankcase for between housings and shafts and housings arranged seals of the engine creates a low-pressure pressure curve.

Description

The invention relates to a device for controlling a pressure gradient in a cylinder crankcase of an internal combustion engine with at least one reciprocating piston according to the preamble of patent claim 1.

In internal combustion engines of the reciprocating piston type with closed crankcase, deviations from the atmospheric pressure also result below the reciprocating pistons during operation in work spaces. These are caused, on the one hand, by volume changes caused by moving pistons and, on the other hand, by gases accumulating in the crankcase from the working process.

It is an internal combustion engine with a crankcase known US 5,542,401 known, comprising means for maintaining a substantially constant partial vacuum in said crankcase. This device is formed by a vacuum controlled valve with a spring-loaded Hukolben.

The object of the invention is to design a device for controlling the pressure level in a cylinder crankcase, which is characterized by simple implementation and execution and good function.

According to the invention, this object is solved by the features of patent claim 1. Further, the invention ausgestaltende features are included in the subclaims.

The advantages achieved by the invention are to be seen in the fact that the device causes a pressure and negative pressure influencing pressure curve and a medium pressure level in a crankcase of the cylinder crankcase sophisticated, in such a way that in the cylinder crankcase for between housings and shafts and housings or the like. arranged seals of the engine, a low-pressure pressure curve is formed. It is exemplary that the device comprises valves operating in the reverse direction, with which the pressure level and negative pressure can be controlled by designing opening cross sections and spring rates. The latter is supported by the fact that the valves are designed in such a way that at higher rotational speeds of the internal combustion engine, a defined low negative pressure arises on average.

An example is that the valves are formed by one-way valves, which are shown as flutter valves, the flutter valves are designed differently for the overpressure and the negative pressure. In this case, standards are set by the fact that a first and a second flutter valve and for the negative pressure a single flutter valve are effective for influencing the overpressure.

A design-favorable solution is achieved if the flutter valves are arranged adjacent to a boundary plane of a cylinder head connected to the cylinder crankcase, which limiting plane is followed by a cover surrounding a pressure chamber of a crankcase ventilation of the cylinder crankcase. Said solution is optimized by the fact that the flutter valves and the opening cross-sections are part of a plate-like support extending over the boundary between the cylinder head and cover. Finally, leaf spring-like valve tongues of the flutter valves are held on the support by means of screws in position.

In the drawing, an embodiment is shown, which will be explained below.

• 1 eine Schrägansicht auf eine Brennkraftmaschine mit einem Maschinengehäuse,
• 2 eine Ansicht auf eine Einrichtung zur Steuerung eines Druckverlaufs in einem Zylindergehäuse der Brennkraftmaschine nach 1,
• 3 eine Einzelheit X der 2 in größerem Maßstab,
• 4 einen Schnitt nach der Linie IV-IV der 3,
• 5 einen Teilquerschnitt der Brennkraftmaschine im Bereich einer Dichtung zwischen einer rotierenden Welle und einem Zylinderkurbelgehäuse,
• 6 eine Einzelheit Y der 1 in größerem Maßstab.

Show it

• 1 an oblique view of an internal combustion engine with a machine housing,
• 2 a view of a device for controlling a pressure curve in a cylinder housing of the internal combustion engine according to 1 .
• 3 a detail X the 2 on a larger scale,
• 4 a section along the line IV-IV of 3 .
• 5 a partial cross section of the internal combustion engine in the region of a seal between a rotating shaft and a cylinder crankcase,
• 6 a detail Y the 1 on a larger scale.

An internal combustion engine 1 , which is designed, for example, to drive a water, land vehicle or the like and operates in four-stroke work process, is provided with a crankshaft system comprising two parallel crankshafts. The latter is not shown, but the pamphlets EP 2 696 054 B1 and DE 10 2015 000 122 B3 removable. A machine housing Mg of the internal combustion engine 1 forming cylinder crankcase 2 is provided with at least one piston bore in which a reciprocating piston is moved back and forth and the crankshaft system with the two crankshafts drives - the latter is not shown-.

Into the internal combustion engine 1 is a facility 3 for controlling a pressure level in the cylinder crankcase 2 integrated, the one through Piston movements caused overpressure Üb and negative pressure Un in a crankcase 4 influenced said cylinder crankcase. And in the way that in the crankcase 4 of the cylinder crankcase 2 for between walls 5 of housings 6 as well as waves, for example, a crankshaft 7 arranged seals 8th the internal combustion engine 1 a low-pressure pressure curve. Unpressurized Un- creates -Fig. 5 and 6-. The device 3 includes reverse-acting valves 9 , with which the pressure level Ub and negative pressure Un comprehensive pressure level is controllable by design of opening cross-sections and spring rates -Fig. 3 and 4-. For this design, iterative and / or computational methods can be used taking into account defined internal combustion engine characteristics. And the decor 3 is designed in such a way that at higher speeds of the internal combustion engine 1 a defined low vacuum Un arises on average.

The valves 9 are formed by one-way valves, which disposable valves, as flutter valves 10 . 11 and 12 are formed. The flutter valves 10 . 11 and 12 wise, valve openings 13 . 14 and 15 and spring leaf-like valve tongues 16 . 17 and 18 on, with the valve tongues 16 . 17 and 18 on a plate-like, for example, metal, plastic, composite material or the like. existing Flatterventilträger 19 are attached. For overpressure Üb and Unterdruck Un are different concepts for the flutter valves 10 . 11 and 12 shown. For this purpose, a first butterfly valve is for influencing the overpressure Üb 10 and a second flutter valve 11 and for the negative pressure Un a single flutter valve 12 effective. The flutter valves 10 . 11 and 12 or valve tongues take during operation of the internal combustion engine 1 by the occurring pulsation in the cylinder crankcase 2 a closed position Sst and an open position east. The with screws S1 . S2 and S3 at the flutter valve carrier 19 attached flutter valves 10 . 11 and 12 are adjacent to a limiting plane Bgeb one with the cylinder crankcase 2 connected cylinder head 20 arranged. The boundary plane Bgeb includes a pressure chamber 21 a not shown crankcase ventilation of the cylinder crankcase 2 surrounding cover 22 at. The flutter valve carrier 19 extends substantially completely over the boundary plane Bgeb between the cylinder head 20 and cover 22 ,

Finally, a flange 23 the Flatterventilträgers 19 between a support wall 24 the cover and a wall section 25 of the cylinder head 20 clamped. In other words, the flutter valve carrier 19 or the flange 23 Also acts as a seal between the cylinder head 20 and cover 22 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5542401 [0003]
• EP 2696054 B1 [0011]
• DE 102015000122 B3 [0011]

Claims (10)

Device for controlling a pressure level in a cylinder crankcase of an internal combustion engine with at least one reciprocating piston, which is moved in a piston bore of the cylinder crankcase and is operatively connected to a crankshaft system of the internal combustion engine, characterized in that the device (3) has an overpressure (Ub) and negative pressure (Un) influencing pressure profile and a mean pressure level in a crank chamber (4) of the cylinder crankcase (2) causes, in such a way in the cylinder crankcase (2) arranged between housings and shafts (crankshaft 7) and housings seals (8) of the internal combustion engine (1) a low-pressure pressure curve is formed. Setup after Claim 1 , characterized in that the device (3) operating in reverse directions valves (9), with which the pressure (U) and vacuum (Un) comprehensive pressure level is controllable by design of opening cross-sections and spring rates. Setup after Claim 2 , characterized in that the valves (9) of the device (3) are designed in such a way that at higher rotational speeds of the internal combustion engine (1) a defined low negative pressure (Un) arises on average. Device according to one of the preceding claims, characterized in that the valves (9) are formed by one-way valves. Setup after Claim 4 , characterized in that the one-way valves by flutter valves (10, 11 and 12) are formed. Furnishing according to the Claims 2 to 5 , characterized in that for the overpressure (Ub) and the negative pressure (Un) different concepts for the flutter valves (10, 11 and 12) are provided. Setup after Claim 6 , characterized in that for influencing the overpressure (Ub) a first and a second flutter valve (10 and 11) and for the negative pressure (Un) a single flutter valve (12) is effective. Furnishing according to the Claims 1 and 7 , Characterized in that the flap valves (10, 11 and 12) adjacent to a boundary plane (Bgeb) of the cylinder crankcase (2) the cylinder head (20) connected are arranged, to which boundary plane (Bgeb) a pressure chamber (21) of a crankcase breather of Cylinder crankcase (2) surrounding cover (22) connects. Furnishing according to the Claim 8 , characterized in that the flutter valves (10, 11 and 12) with valve tongues (16, 17 and 18) and the valve openings (13, 14 and 15) are part of a Flatterventilträgers (19) substantially completely over the boundary plane ( Bgeb) between the cylinder head (20) and cover (22). Setup after Claim 9 , characterized in that the spring leaf-like valve tongues (16, 17 and 18) of the flutter valves (10, 11 and 12) on the Flatterventilträger (19) by means of screws (S1, S2 and S3) are held in position.

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