EP1472436A1

EP1472436A1 - Cylinder head

Info

Publication number: EP1472436A1
Application number: EP02805230A
Authority: EP
Inventors: Karsten Mischker; Michael Huebel; Uwe Hammer; Volker Beuche; Peter Lang; Stefan Reimer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2002-01-29
Filing date: 2002-11-28
Publication date: 2004-11-03
Also published as: WO2003064824A1; JP4499423B2; US6948463B2; JP2005516147A; DE10203273A1; US20040154565A1

Abstract

Disclosed is a cylinder head (10) for the combustion cylinder of a combustion engine, comprising at least one inlet and one outlet and charge exchange valves (11) which are actuated by electrohydraulic valve actuators (15) and control the at least one intake as intake valves (111) and the at least one outlet as exhaust valves (112). In order to preproduce a compact complete module which can be tested for operability and can be mounted in the engine block without requiring any premounting, the cylinder head (10) is provided with means for fixing the valve actuators (15) and at least one high-pressure rail (37) feeding a pressurized fluid and at least one return rail recycling a fluid. Said rails are provided with coupling openings (39, 40) hydraulically coupling the valve actuators (15).

Description

cylinder head

State of the art

The invention relates to a cylinder head for a combustion cylinder of an internal combustion engine according to the preamble of claim 1.

In an internal combustion engine with an electrohydraulic valve control, as is known from DE 198 26 047 AI, the electrohydraulic valve actuators are supplied with high-pressure fluid, preferably hydraulic oil, for actuating the gas exchange valves and, at the same time, fluid is removed from the valve actuators under low pressure returned to a fluid reservoir ∑. The valve actuators each have a double-acting working cylinder with an actuating piston which is displaceable therein and which is connected to the associated gas exchange valve and divides the working cylinder into two hydraulic working spaces. By appropriately controlling the pressure of the fluid in the work spaces by means of two Electrical control valves, preferably designed as 2/2-way solenoid valves, the control piston is displaced in one or the other direction, thereby opening or completely closing the associated gas exchange valve.

Advantages of the invention

The cylinder head according to the invention with the features of claim 1 has the advantage that with the attachment of the valve actuators for actuating the gas exchange valves, the fluid supply to the valve actuators is simultaneously established. The cylinder head equipped with the valve actuators forms a compact module that can be checked for functionality as a separate component and delivered to the customer. The customer only has to put the modules on the

Mount the combustion cylinder of the engine block and get the internal combustion engine with an equipped, function-tested, electro-hydraulic valve control without additional pre-assembly work.

Advantageous further developments and improvements of the cylinder head specified in claim 1 are possible through the measures listed in the further claims.

According to a preferred embodiment of the invention, there are two line pairs, each formed by a high-pressure line and a return line, which preferably run parallel to one another on the cylinder head. One pair of lines has the coupling openings for valve actuators of the intake valves and the other pair of lines

Coupling openings for valve actuators of the exhaust valves. This constructive measure provides the fluid supply for the inlet and outlet side via separate hydraulic lines, so-called rails.

According to an advantageous embodiment of the invention, the high pressure lines and the return lines are integrated in the cylinder head, i.e. they are either already during the casting of the cylinder head or through a further machining process, e.g. generated by drilling or milling.

According to a preferred embodiment of the invention, the high-pressure lines are designed as separate components and attached to the cylinder head. This enables the use of materials that have a higher strength than the cylinder head usually manufactured as cast aluminum. The high-pressure lines can be clamped to the cylinder head by means of clamps, which in turn are screwed onto the cylinder head. Alternatively, it is also possible to cast the high-pressure lines by inserting them into the mold like a core during the mold casting process and thus the material of the cylinder head flowing around them.

According to an advantageous embodiment of the invention, the fixing means for the valve actuators on the cylinder head have centering openings and threaded holes which are made in the outer cylinder head surface, the centering openings simultaneously serving to pass through the valve stems of the gas exchange valves.

According to a preferred embodiment of the invention, there is at least one leakage line in the cylinder head Return of leakage fluid is provided, which is connected to the centering openings via connecting channels. Each line pair of high-pressure and return line is preferably assigned a leakage line which runs parallel to the line pair and is integrated in the cylinder head. Fluid leaks in the valve actuators are discharged via the leakage lines and are preferably separated for the inlet and outlet side.

drawing

The invention is described below with reference to an embodiment shown in the drawing. Show it:

1 is a plan view of a cylinder head for a combustion cylinder of an internal combustion engine,

2 a section along the line II - II in Fig. 1,

3 is a perspective view of the cylinder head according to FIG. 1 pre-assembled by fitting valve actuators to form a functionally testable complete module, FIG.

4 shows a perspective illustration of an actuator housing of a valve actuator in FIG. 3, 5 is a side view of the actuator housing in the direction of arrow V in Fig. 4,

6 shows a section along the line VI-VI in FIG. 5,

Fig. 7 is a block diagram of a valve actuator for explanation of functions.

Description of the embodiment

The cylinder head 10 for a combustion cylinder of an internal combustion engine, which can be seen in plan view in FIG. 1 and in section in FIG. 2, is provided with a total of four gas exchange valves 11, of which only the valve stems 111 are shown in FIGS. 1 and 2.

7 shows a section of the cylinder head 10 in the area of a gas exchange valve 11 in the sectional view. In a known manner, the gas exchange valve 11 closes an opening 12 in the cylinder head 10, which in turn is placed on the combustion cylinder and closes a combustion chamber formed in the combustion cylinder in a gas-tight manner. The gas exchange valve 11 has a valve seat 13 which surrounds the opening 12 in the cylinder head 10 and a valve member 14 with a valve closing body 142 which sits on an axially displaceably guided valve stem 141 and which cooperates with the valve seat 13 to close and open the opening 12. By moving the

Valve stem 141 lifts in one or the other axial direction the valve closing body 142 from the valve seat 13 or sits on the valve seat 13.

As can be seen in FIGS. 1 and 2, two of the four gas exchange valves 11 are arranged next to one another and the two pairs of gas exchange valves 11 are placed on the cylinder head 10 in a symmetrical manner. The one pair of gas exchange valves 11 forms the inlet valves 111 and the pair of gas exchange valves 11 placed symmetrically therewith forms the outlet valves 112 for the combustion chamber in the combustion cylinder. Each inlet valve 111 controls an inlet opening 12 with its valve member 142 and each outlet valve 112 controls an outlet opening 12 with its valve member 142.

Each gas exchange valve 11 is actuated by an electro-hydraulic valve actuator 15. The structure and mode of operation of the electrohydraulic valve actuator 15 are known (cf. DE 198 26 047 AI) and are shown in FIG. 7 in the block diagram. The valve actuator 15 has an actuator housing 16 in which a double-acting, hydraulic working cylinder 17 and two electrical control valves 18, 19, for example designed as 2/2-way solenoid valves, are accommodated. In the working cylinder 17, an adjusting piston 20, which is connected to the valve stem 141 of the gas exchange valve 11, is axially displaceable and divides the working cylinder 17 into a lower working chamber 21 and an upper working chamber 22. The lower working space 21 is immediate and the upper working space 22 via the first control valve 18 with a fluid inflow opening 23 in

Actuator housing 16 connected. The upper work space is 22 additionally connected via the second control valve 19 to a fluid drain opening 24 in the actuator housing 16. The piston surface of the adjusting piston 20 delimiting the upper working chamber 22 is larger than the piston surface of the adjusting piston 20 delimiting the lower working chamber 21

Control valves 18, 19 are electrically controlled, for which purpose 16 electrical connection contacts 25, 26 are present on the actuator housing.

In Fig. 4 and Fig. 5, the actuator housing 16 (without hydraulic cylinder and electrical control valves) is shown in a constructive design in different views. The fluid inflow opening 23 and the fluid outflow opening 24 are arranged in a flat housing surface 161. Concentric to the fluid inlet opening 23 and

Fluid drain opening 24 is an annular groove 31 and 32 machined into the housing surface 161, which serves to receive a sealing ring, not shown here. An opening 28 (FIG. 6), which is concentrically enclosed by a hollow pin 27 projecting from the housing surface 161, is incorporated in the same housing surface 161. A cavity 47 for receiving the working cylinder 17 is arranged in the actuator housing 16 coaxially with the opening 28 or hollow pin 27. Furthermore, two blind-hole-like receiving chambers 29, 30 are formed in the actuator housing 16, which open on the housing surface 162 facing away from the housing surface 161 (FIG. 5). The receiving chambers 29, 30 serve to accommodate the control valves 18, 19 which are pushed into the receiving chambers 29, 30 from the housing surface 162. As the sectional view in FIG. 6 shows for the receiving chamber 29 which can be seen in sections, runs from the bottom of the receiving chambers 29 to the inside of the hollow pin 27, a connecting channel 33, via which a fluid leakage emerging at the electrical control valve 18 can be drained off to the opening 28. As is not shown here, an identical connecting channel leads to the receiving chamber 30. As shown in FIGS. 4 and 5, protruding ears are formed on the narrow side of the actuator housing 16, in each of which a through hole 35 for inserting fasteners, preferably a screw 36 (Fig. 3) are introduced. The through bores 35 run parallel to the axis of the hollow pin 27.

In Fig. 3 with actuator 17 and control valves 18, 19 completed actuator housing 16 in constructive

See execution. In each case one valve actuator 15 is used to actuate a gas exchange valve 11, so that in the cylinder head 10 shown in FIG. 1 with four gas exchange valves 11 four valve actuators 15 have to be attached to the cylinder head 10, with the valve stem 141 of the associated gas exchange valve 11 with the actuating piston simultaneously 20 must be coupled in the working cylinder 17.

The cylinder head 10 is now designed so that when the valve actuator 15 is attached and the valve actuator 15 is attached to the cylinder head 10, the fluid supply to the valve actuator 15 is ensured at the same time. As shown in FIGS. 1 and 2, there are two high-pressure lines 37, so-called high-pressure rails, on the cylinder head 10 for supplying high-pressure fluid to the valve actuators 15 and Two return lines 38, so-called return rails, are provided for discharging fluid under low pressure from the valve actuators 15 for the purpose of returning them to a fluid reservoir. The high-pressure lines 37 and the return lines 38 run parallel to one another, a pair consisting of a high-pressure line 37 and a return line 38 being assigned to the inlet valves 111 and the outlet valves 112. The high-pressure lines 37 and the return lines 38 are provided with coupling openings 39 and 40 for the hydraulic coupling of the valve actuators 15. The number of coupling openings 39 in the high-pressure lines 37 and the number of coupling openings 40 in the return lines 38 is the same and corresponds to the number of inlet valves 111 and outlet valves 112. In the exemplary embodiment in FIGS

High-pressure lines 37 are designed as separate components which are clamped on the cylinder head 10 with clamping brackets 41, which in turn are screwed to the cylinder head 10. The return lines 38 are integrated in the cylinder head 10 and are either already generated when the cylinder head 10 is cast or are drilled on the cylinder head 10 by an additional machining process. Leakage lines 42, so-called leakage rails, are also integrated in the cylinder head 10 and are manufactured like the return lines 38. Each pair of high pressure line 37 and

Return line 38 is assigned a leakage line 42, which runs parallel to high-pressure line 37 and return line 38.

Fixing means are provided on the cylinder head 10 for coupling the valve actuator 15 to the cylinder head 10 Center holes 43 and threaded holes 44 include. Each centering opening 43 receives the hollow pin 27 projecting on the actuator housing 16 of the valve actuator 15 in a form-fitting manner, while the threaded holes 44 are congruent with the two on each actuator housing 16

Through holes 35 are placed. The centering openings 43 serve at the same time for the passage of the valve stems 141 of the gas exchange valves 11. Furthermore, the coupling openings 39, 40 are arranged so that when the actuator housing 16 is placed with the hollow pin 27 immersed in the centering opening 43, the fluid inflow openings 23 onto the coupling openings 39 in the high pressure line 37 and the fluid drain openings 24 sit congruently on the coupling openings 40 in the return line 38. The sealing rings lying in the ring grooves 31, 32 ensure a fluid-tight connection between the fluid supply and fluid outflow openings 23, 24 in the actuator housing 16 and the coupling openings 39, 40, when screwing the screws 36 passed through the through holes 35 on the actuator housing 16 into the Threaded holes 44, the actuator housing 16 are pressed onto the cylinder head 10. When the hollow pins 27 are inserted into the centering openings 43, the valve stems 141 of the gas exchange valves 11 projecting through the latter are simultaneously coupled to the actuating pistons 20 of the working cylinders 17.

As can be seen from the sectional view in FIG. 2, the centering openings 43 are connected to the leakage lines 42 via connecting channels 45, namely those

Inlet valves 111 associated centering openings 43 on the a leakage line 42 and the centering openings 43 assigned to the outlet valves 112 are connected to the other leakage line 42. The fluid leaks occurring in the valve actuators 15, that is to say on the one hand on the working cylinder 17 and on the other hand in the control valves 18, 19, are conducted through these connecting channels 45 into the leakage lines 42 and from there are returned to a fluid reservoir.

In Fig. 3 the cylinder head 10 equipped with four valve actuators 15 is shown in perspective, which represents a compact complete module with functionally testable, electrohydraulic valve control, which only has to be placed gas-tight on a combustion cylinder in the engine block of an internal combustion engine and connected to a fluid supply device. In the drawing, only a single cylinder variant is shown. By lining up several such modules according to FIG. 3, it is possible to implement in-line engines and V-engines with any number of cylinders. For this purpose, the high pressure lines 37,

Return lines 38 and the leakage lines 42 are formed at the ends such that the adjoining ends of the said lines 37, 38, 42 can be joined liquid-tightly or liquid-tightly joined together if a similar module is arranged. As illustrated in FIG. 3, the high-pressure lines 37 are inserted into one another with correspondingly configured projections 371 and 372, while the high-pressure lines 37 and leakage lines 42 open into flanges 46, which are placed flat against one another with the interposition of a seal and screwed together. Alternatively, it is also possible to use multi-cylinder versions to be produced in one piece, ie to cast all cylinder heads in one piece. All lines or rails 37, 38, 42 are then drilled through the entire multi-cylinder head and all cylinders are supplied by the rails.

The invention is not restricted to the exemplary embodiment described. The return lines 38 can thus be cast onto the cylinder head 10 as a separate component. For this purpose, the high-pressure lines 37 are inserted into the mold like a core during the mold casting process, so that the material of the cylinder head 10 flows around them, thereby creating a connection with the cylinder head 10.

The high pressure lines 37 can, however, just like that

Return lines 38 and the leakage lines 42 can be integrated into the cylinder head 10 by already generating them when the cylinder head 10 is cast or by drilling them during a further machining process. The advantage of the high-pressure lines 37 produced as separate components lies in the possibility of using materials which have a higher strength than the die-cast aluminum of the cylinder head 10.

Claims

Expectations

1. Cylinder head for a combustion cylinder

Internal combustion engine, with at least one inlet opening and at least one outlet opening and with gas exchange valves (11) which can be actuated by means of electrohydraulic valve actuators (15) and which control the at least one inlet opening as the inlet valve (111) and the at least one outlet opening as the outlet valve (112) at least one high-pressure line (37) for supplying high-pressure fluid and at least one return line (38) for returning fluid, which have coupling openings (39, 40) for the hydraulic coupling of the valve actuators (15), and by means for fixing the valve actuators (15).

2. Cylinder head according to claim 1, characterized in that two pairs of lines formed by a high pressure and a return line (37, 38) are present, which preferably run parallel to one another, and that the one pair of lines, the coupling openings (39, 40) for valve actuators (15) of the inlet valves (111) and the other pair of lines Coupling openings (39, 40) for valve actuators (15) of the outlet valves (112).

3. Cylinder head according to claim 2, characterized in that the number of coupling openings (39, 40) in each line (37, 38) of a line pair corresponds to the number of intake valves (111) or exhaust valves (112).

4. Cylinder head according to one of claims 1-3, characterized in that the high pressure and return lines (37, 38) are integrated in the cylinder head (10).

5. Cylinder head according to one of claims 1-3, characterized in that the high pressure lines (37) are designed as separate components.

6. Cylinder head according to claim 5, characterized in that the high pressure lines (37) on the cylinder head (10) are mechanically attached.

7. Cylinder head according to claim 6, characterized in that the high pressure lines (37) of clamping brackets (41) are spanned, which on the cylinder head (10) by fastening means, e.g. Screws.

8. Cylinder head according to claim 5, characterized in that the high pressure lines (37) from the material of the cylinder head (10) are enclosed.

9. Cylinder head according to one of claims 1-8, characterized in that the fixing means have centering openings (43) and threaded holes (44) which are introduced into the outer cylinder head surface (161), and that the gas exchange valves (11) with their

Valve stems (111) are guided through the centering openings (43).

10. Cylinder head according to claim 9, characterized in that at least one leakage line (42) is provided for returning leakage fluid, which communicates with the centering openings (43) via connecting channels (45).

11. Cylinder head according to claim 2 and 10, characterized in that each line pair is assigned a parallel leakage line (42) and that the one leakage line (42) via the connecting channels (45) with all centering openings (43) for receiving the valve actuator (15) for the inlet valves (111) and the other leakage line (42) via the connecting channels (45) with all centering openings (43) for receiving the valve actuators (15) for the outlet valves (112).

12. Cylinder head according to claim 10 or 11, characterized in that the high pressure lines (37), the return lines (38) and the leakage lines (42) are formed at the end for attaching similar lines of a further cylinder head (10).

13. Module for at least one combustion cylinder of an internal combustion engine with electrohydraulic valve control, the at least one cylinder head (10) according to one of claims 1 - 12 and on the cylinder head (10) releasably attached, electro-hydraulic

Has valve actuator (15), the number of which corresponds to the number of gas exchange valves (11) present in the cylinder head (10).

14. Module according to claim 13, characterized in that each valve actuator (15) has an actuator housing (16) which in a flat housing surface (161) has a fluid inlet opening (23), a fluid outlet opening (24) and one of a projecting hollow pin (27th ) Enclosed opening (28) for the passage of a valve stem (141) of a gas exchange valve (11), which are arranged so that when the valve head (10) is attached to the valve head (15), the fluid inflow opening (23) on the coupling opening (39) of the high pressure line (37) and the fluid drain opening

(24) lies congruently on the coupling opening (40) of the return line (38) and the hollow pin (27) engages positively in the centering opening (43).

15. Module according to claim 14, characterized in that in the actuator housing (16) two blind hole-like receiving chambers (29, 30) are provided for each one electrical control valve (18, 19) which in the housing surface facing away from the flat housing surface (161) (161) 162) and that A connecting channel (33) runs from the bottom of each receptacle (29, 30) to the inside of the hollow pin (27).

16. Module according to claim 14 or 15, characterized in that in the flat housing surface (161) the fluid inlet and outlet opening (23, 24) surrounding annular grooves (31, 32) are incorporated for receiving sealing rings.

17. Module according to one of claims 14 - 16, characterized in that in the actuator housing (16) with the hollow pin (27) coaxial cavity (47) is incorporated, in which one with the fluid inlet and outlet opening (23, 24) connected hydraulic working cylinder (17) is inserted, and that in the working cylinder (17) an actuating piston (20) is axially displaceably connected to the valve stem (141) of the gas exchange valve (11) inserted into the hollow pin (27).

18. Module according to one of claims 14 - 17, characterized in that on the actuator housing (16)

Through openings (35) are provided for the passage of fastening screws (36) which can be screwed into threaded holes (44) made in the cylinder head (10).