WO2017174058A1

WO2017174058A1 - Device for cooling a piston of an internal combustion engine

Info

Publication number: WO2017174058A1
Application number: PCT/DE2017/100142
Authority: WO
Inventors: Jens Hoppe; Michael Schwarz; Stefan Konias; Martin Steigerwald
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2016-04-07
Filing date: 2017-02-21
Publication date: 2017-10-12
Also published as: DE102016205819A1; DE102016205819B4

Abstract

The invention relates to a device (1) for controlling a hydraulic medium supply of an internal combustion engine, comprising a supply line (3) which extends between a feed connector (P) and a supply connector (A), and a closure element (5a) which is actuated by means of a hydraulic medium pressure, is arranged between the feed connector (P) and the supply connector (A), and connects the feed connector (P) hydraulically to the supply connector (A) if a threshold pressure is exceeded. A first surface (6) of the closure element (5a) faces the supply line (3) and can be brought into contact with a sealing seat (7) in a spring-loaded manner. A second surface (9) of the closure element (5a) faces away from the supply line (3) and delimits a pressure chamber (10). The invention also comprises a solenoid valve (26) which controls a hydraulic connection (11) between the supply line (3) and the pressure chamber (10), wherein the hydraulic connection (11) extends from the first surface (6) to the second surface (9), and wherein the hydraulic connection (11) opens via an inflow opening (13) into the pressure chamber (10), wherein the inflow opening (13) can be closed with the aid of a closing body (14) of the solenoid valve (26).

Description

Device for cooling a piston of an internal combustion engine

The invention relates to a device for controlling a hydraulic fluid supply, in particular for the control of large engine oil volume flows at the same time as comparatively small power consumption of a solenoid valve. The invention thus relates, for example, to a device for cooling a piston of an internal combustion engine, comprising a supply line extending between an inlet connection and a supply connection and a closure element actuated by means of a hydraulic medium pressure, which is arranged between the inlet connection and the supply connection and which exceeds one Threshold pressure hydraulically connects the inlet port to the supply port, wherein a first surface of the closure element faces the supply line and can be brought into spring-loaded engagement with a sealing seat and wherein a second surface of the closure element facing away from the supply line and a pressure chamber limited, and comprising a solenoid valve, which controls a hydraulic connection between the supply line and the pressure space, wherein the hydraulic connection from the first to the second surface extends. Such a device is known, for example, from EP 2 778 364 A1. Shown is a device for cooling a piston of an internal combustion engine with an inlet connection and an outlet connection, wherein a main line extends between the inlet connection and the outlet connection. Parallel to the main line an auxiliary line is arranged, which thus also extends between the inlet port and the drain port. By means of a first blocking body, the main line can be blocked, wherein a hydraulic connection can be made to a arranged in the auxiliary line blocking chamber via an axially extending through the locking body channel. With the aid of a second closing body, the auxiliary line can be blocked. As a result, a hydraulic fluid pressure builds up in the lock chamber, whereby the first locking body brought into contact with a sealing seat and the main line closed becomes. A subsequent release of the auxiliary line thus leads to an opening of the main line.

It is therefore the object of the invention to improve the construction of a device for the control of a hydraulic fluid supply.

The object is solved by the features of claim 1. A device for controlling a hydraulic fluid supply of the type mentioned is therefore characterized by the fact that the hydraulic connection opens into the pressure chamber via an inlet opening, wherein the inlet opening can be closed by means of a closing body of the solenoid valve.

The pressure chamber can thus be separated from the hydraulic fluid supply, whereby the second surface is not acted upon by a hydraulic medium pressure. The closure element thus releases the supply line when a defined pressure is exceeded. Advantageously, the opening can be designed to exceed a minimum pressure - and at the same time a failsafe functionality can be realized: A pressure-dependent opening and closing of the closure element is ensured even in the event that the solenoid can not fulfill its functions. In addition, it is ensured that the closure element opens only when a certain minimum pressure of the hydraulic fluid supply is exceeded, so that the pressure build-up is not affected by an early connection with the environment. The pressure can be defined in particular by the force of a spring, which presses the closure element in the direction of the sealing seat. The spring can be arranged in particular in the pressure chamber, wherein the pressure chamber is limited by a tubular housing and by the closure element on the one hand and by a spring plate on the other. The spring plate can be pressed in particular in the tubular housing, wherein the Einpresstiefe can be influenced to adjust the spring force. In an advantageous embodiment, the pressure chamber has a drain opening, which can be closed by means of a second closing body of the solenoid valve. The drain opening can be arranged in particular on the spring plate. The drain opening can be in fluid-conducting connection with the drain connection T for venting, whereby a connection to the environment can be established. In addition, the draining hydraulic fluid can also be supplied to the volume flow which escapes from the supply port A of the device. Advantageously, thus the pressure chamber can be optionally connected to the inlet and the drain. In a further development, a check valve can therefore be arranged in the region of the outlet connection T, for example in conjunction with the second closing body. In this way, a return flow of the hydraulic fluid is avoided in the pressure chamber.

In an advantageous development, the closing body does not close the inlet opening when the drain opening is closed. In this way, a build-up of pressure in the pressure chamber is effected so that the hydraulic fluid pressures acting on the closure element on the first surface and on the second surface can substantially equalize. The pressure compensation can be designed in particular by the design of the first and second surfaces and by their relation to each other.

In an advantageous development, the second closing body does not close the drain opening when the inlet opening is closed. In this way, a vent can take place, which is required for an actuating movement of the closure element or supports it.

In an advantageous development of the closing body and the second closing body are arranged on a push rod of the electromagnet. In this case, the push rod can pass through the drain opening, wherein the second closing body is disposed beyond the pressure chamber. The closing body may also be referred to as a first closing body in the presence of a second closing body. The first closing body may be arranged separately from the push rod and bear against one end of the push rod. However, the first closing body can also be sonic welding be connected to the push rod, for example, to compensate for axial tolerances can.

In an advantageous embodiment, the second closing body or a drain port T comprises a check valve. The second closing body may be designed such that, when the position is closed, hydraulic fluid can not pass through the discharge opening in any direction. In the open position, however, an outflow is possible, but entry into the pressure chamber is prevented by the check valve. The second closing body can also form the check valve body as the closing body. The closing body can be guided in this case along the push rod and spring loaded in the open position of the second closing body are brought into contact with a sealing seat of the drain opening. Alternatively, for example, a check valve ball can be arranged in a bore, wherein the bore forms the drain port T. A check valve is necessary, for example, in the event that the drain port T is not in direct contact with the environment, but with the hydraulic fluid flow, which leaves the valve via the drain opening A.

In an advantageous embodiment, the closure element comprises a hollow cylindrical piston. In particular, the cavity of the hollow cylindrical piston may be a channel or a bore, each extending from one axial end to a second axial end of the hollow cylindrical piston. The hollow space of the hollow cylindrical piston can advantageously form part of the hydraulic connection.

In an advantageous development of the hollow cylindrical piston carries on a front side, which faces the pressure chamber, a cup-shaped sleeve, wherein the cup-shaped sleeve forms the second surface of the closure element and wherein the cup-shaped sleeve has a recess as an inlet opening, through which the baffle ßelstange passes through the closing body.

The arrangement of the closing body in the hydraulic connection ensures that in a non-actuated, ie in the de-energized or de-energized State of the solenoid, the inlet opening can be closed only by hydraulic fluid pressure. The inlet opening is thus closed in an advantageous development with non-actuated solenoid valve by the closing body. The design of the closure element with a hollow cylindrical piston and a cup-shaped sleeve allows a particularly cost-effective design. The cup-shaped sleeve can be formed, for example, as a formed part, in particular deep-drawing or extruded part, from sheet metal. Alternatively, the cup-shaped sleeve can also be made of plastic, in particular duroplastic.

Between the inner wall of the component, which receives the closure element (recording, in particular designed as a tubular housing), and the cup-shaped sleeve can be provided a tight clearance fit. The outer diameter of the cup-shaped sleeve thus forms the guide diameter of the closure element, which is characterized by high accuracy and a small leakage gap.

The hollow cylindrical piston and the cup-shaped sleeve, however, may be aligned with each other with a loose clearance. This creates an area between see cup-shaped sleeve and recording, which is characterized by a good seal. The hollow cylindrical piston, however, can align itself with the position of the sealing seat and compensate for production-related coaxial errors.

The cup-shaped sleeve and the hollow cylindrical piston can be firmly connected. In particular, a groove can be provided on the outer circumference of the hollow cylindrical piston, into which an embossing of the cup-shaped sleeve engages. In addition to a positive connection and a non-positive connection, for example by means of a press fit, or an adhesive bond is conceivable. The hollow cylindrical piston can be designed as a turned part and thus emerge from a cutting process. Alternatively, the hollow cylindrical piston can also be designed as extruded part or consist of plastic. The hollow cylindrical piston may have a fuse, by means of which the push rod with the hollow cylindrical piston remains in communication. Such a captive can, for example, be designed such that a paragraph at the end facing the supply line holds the closing body in the cavity of the hollow cylindrical piston. In particular, the closing body can not be fixedly connected to the push rod and bear against the push rod at the end face. In addition, the closing body can spring-loaded on the hollow cylindrical piston, in particular the paragraph can serve as a spring seat. It is ensured that the inlet opening remains closed even with vibrations, whereby unwanted circuits of the closure element can be avoided.

The valve seat may originate from a turning operation or be used as a component separate from the receptacle. When designed as a separate component, the surface properties can be specifically adapted to the respective application. The attachment of a separate component can be done for example by means of a press fit or a snap ring.

The spring plate can be a deep-drawn part. Alternatively, the spring plate can be integrally formed on the receptacle, for example, by a rotating machining. The push rod may consist of plastic or emerge from a cutting machining as a turned part.

The second closing body may be integrally formed on the push rod. Alternatively, however, a separate from the push rod design is possible. In this case, moreover, an application of the force of a spring offers itself, which presses the second closing body against the sealing seat of the drainage opening.

In an advantageous development of the closing body has a conical or spherical shaped portion which is provided for sealing engagement with the inlet opening, and a cylindrically shaped portion which is guided on the inner peripheral surface of the hollow cylindrical piston, wherein a conically or spherically shaped Section extending flattening of the cylindrically shaped section a hydraulic connection between supply line and inlet opening leaves. A hydraulic connection between the first surface and the second surface can thus be produced in a structurally inexpensive manner. An end surface of the closing body, which faces the supply line, ensures a reliable admission with a hydraulic fluid pressure. In this way, a displacement of the push rod in the direction of the pressure chamber can be effected.

The device for controlling a hydraulic fluid supply can be used in particular for cooling a piston of an internal combustion engine. In this case, the inlet port communicates with the general engine oil circuit, supplying the engine with pressurized engine oil. The supply connection communicates with at least one nozzle, which acts on at least one piston of an internal combustion engine for cooling with engine oil. However, the device can also generally be used to control large engine oil volume flows while at the same time consuming comparatively little power.

The invention will be explained below with reference to exemplary embodiments.

1 shows an exemplary embodiment of the device for controlling a hydraulic fluid supply;

Fig. 2 illustrates the operating conditions I-VI of the apparatus shown in Fig. 1; Fig. 3 shows an alternative embodiment of the device for controlling a hydraulic fluid supply;

4 shows a further alternative embodiment of the device for the control of a hydraulic fluid supply and

FIG. 5 shows a detail X of the embodiment from FIG. 4.

A possible embodiment of a device 1 for controlling a hydraulic fluid supply is shown in FIG. A provided with sealing rings 23, tubular housing 2, which has a pressed-in pressure piece 24 at one axial end, has at a second axial end an inlet port P and a radial supply port A, which is arranged in the region of the axial end. Between the inlet port P and the drain port A extends a supply line 3, which can be released or closed by means of a hollow cylindrical piston 4 and a cup-shaped sleeve 5 comprehensive closure element 5a.

The closure element 5a is arranged between inlet connection P and supply connection A, wherein a first surface 6 of the closure element 5a faces the supply line 3 and can be brought into spring-loaded engagement with a sealing seat 7. The closure element 5a can be displaced against the force of a spring 8 into an open state, provided that the hydraulic fluid pressure acting on the first surface 6 exceeds a certain threshold value. A vent T allows pressure equalization to the environment or to A.

A second surface 9 of the closure element 5a is arranged facing away from the supply line 3 and defines a pressure chamber 10. The pressure chamber 10 can be brought into fluid communication with the supply line 3 via a hydraulic connection 11, wherein the hydraulic connection 11 is a channel 12, which extends through the hollow cylindrical piston 4. The hydraulic connection 1 1 is controlled by means of a solenoid valve (not fully shown). The hydraulic connection 1 1 extends from the first surface 6 to the second surface 9 of the closure element 5a and flows through an inlet opening 13 of the cup-shaped sleeve 5 in the pressure chamber 10. The hydraulic connection 1 1 is controlled such that a closing body 14 of the Solenoid valve, the inlet opening 13 releases or closes.

The pressure chamber 10 is bounded by the tubular housing 2 and by the closure element 5a on the one hand and by a spring plate 15 on the other. The spring plate 15 is pressed into the tubular housing 2 and also serves as a spring seat for the pressure chamber 10 arranged in the spring 8. The pressure chamber 10 has in addition to the inlet opening 13 also has a drain opening 16 which is closable by means of a second closing body 17 of the electromagnet.

The first closing body 14 and the second closing body 17 are arranged on a push rod 18 of the electromagnet such that the first closing body 14 does not close the inlet opening 13 when the drain opening 16 is closed. At closed inlet opening 13, however, the second closing body 17 does not close the drain opening 16. The push rod 17 passes through both the drain opening 16 and the inlet opening 13, whereby the first closing body 14 is disposed in the channel 12 of the hollow cylindrical piston 4.

The first closure member 14 has a conically shaped portion 19 which can be brought into sealing contact with the inlet opening 13. In addition, there is a cylindrically shaped portion 20 which is guided on the inner peripheral surface of the hollow cylindrical piston 4. A flattening 21 of the cylindrically shaped section 20 extending in the direction of a conically shaped section 19 enables the hydraulic connection 11 between supply line 3 and inlet opening 13. Facing the supply line 3 there is an end face 22 of the piston-shaped first closing body 14, the surface being designed such that that in the de-energized state of the electromagnetic valve, the piston-shaped first closing body 14 rests against the sealing surface of the inlet opening 13.

2 illustrates the operating conditions I-VI, each depending on the system parameters of the solenoid valve - "energized" (on) or "de-energized" (off) - and the exemplary pressure difference - "less than or equal to 0, 9 bar "or" greater 0.9 bar "- set. The pressure difference refers to the hydraulic fluid pressure at the first surface and the ambient pressure.

The starting point is the operating state I with a pressure difference of less than or equal to 0.9 bar and with an electroless solenoid valve. Thus, although a hydraulic fluid pressure can be applied to the first surface 6, a displacement of the closure element 5a against the force of the spring 8 is not effected thereby. Due to the force acting on the end face 22 hydraulic fluid pressure of the closing body 14 abuts against the inlet opening 13, so that the pressure chamber 10 is not supplied with hydraulic fluid. Inlet connection P and supply connection A are not connected to each other.

When the hydraulic medium pressure acting on the first surface 6 increases, a pressure difference greater than 0.9 bar may occur. The device will thus transferred from the first operating state to the operating state II. Due to the force acting on the end face 22 hydraulic fluid pressure and the still currentless solenoid valve, the closing body 14 is still at the inlet opening 13, so that the pressure chamber 10 is not supplied with hydraulic fluid. Between supply connection P and supply connection A, the supply line 3 is released.

In operating state III, the closing process begins. When the pressure difference continues to be greater than 0.9 bar, the electromagnet is energized, as a result of which the closing body 14 releases the inlet opening 13 to the pressure chamber 10. At the same time, the second closing body 17 closes the drain opening 16 of the pressure chamber 10. In the pressure chamber 10, a hydraulic fluid pressure builds up, whereby the pressure difference continues to be greater than 0.9 bar -. However, the pressure in the pressure chamber 10 is adjusted to the hydraulic medium pressure in the region of the first surface 6 and the device is finally transferred to the operating state IV.

A powerless switching of the solenoid valve separates the pressure chamber 10 from the hydraulic medium supply P. At the first surface 6 is still a Hydraulikm ittel- pressure, which leads to a pressure difference greater than 0.9 bar. The pressure difference between the second surface 9 of the now to the environment (to the tank port T or the supply port A) opened pressure chamber 10 and the first surface 6 leads to a reopening of the supply line 3. Then, the device 1 is in the open state, which is the operating condition VI corresponds.

Fig. 3 shows an alternative embodiment of the device 1 for controlling a hydraulic fluid supply. The essential difference with otherwise the same function is that the second closing body 33 is designed as a check valve 34. The second closing body 33 is guided on the push rod 17 and acted upon by the force of a check valve spring 25, which presses the second shooting body 33 against the discharge opening 16. FIG. 4 shows a further alternative embodiment with electromagnet 26, which has substantially the same features as the device 1 shown in FIG. In this variant, the hollow cylindrical piston 4 has a shoulder 27 which prevents the first closing body 14, which is not fixedly connected to the push rod 18, from falling out. The sealing seat 7 is formed separately from the housing 2 in this variant - in this way, the axial position of the hollow cylindrical piston 4 and thus the required for opening threshold pressure can be adjusted. The detail X of Fig. 5 shows an integrated into the drain port check valve 28. A valve ball 29 prevents backflow of the draining hydraulic fluid, wherein the valve ball 29 is held by a plug 30 in a receptacle 31. Lateral flats 32 of the plug 30 allow hydraulic communication with the environment.

LIST OF REFERENCE NUMBERS

1 device

2 housings

3 supply line

4 hollow cylindrical piston

5 cup-shaped sleeve

5a closure element

6 first surface

7 sealing seat

8 spring

9 second surface

10 pressure chamber

1 1 hydraulic connection

12 channel

13 inlet opening

14 (first) closing body

15 pen holder

16 drain opening

17 second closing body

18 pushrod

19 conical section

20 Cylindrical section

21 flattening

22 face

23 seal

24 pressure piece

25 check valve spring

26 solenoid valve

27 paragraph

28 check valve

29 valve ball

30 plugs

31 recording

32 flattening

33 second closing body

34 check valve

P inlet connection

A supply connection

T drain connection (tank)

Claims

claims

1 . Device (1) for controlling a hydraulic fluid supply of an internal combustion engine comprising a supply line (3) extending between an inlet connection P and a supply connection A and a closure element (5a) actuated by means of a hydraulic medium pressure, which is arranged between inlet connection P and supply connection A and which, when a threshold pressure is exceeded, hydraulically connects the inlet connection P to the supply connection A, a first surface (6) of the closure element (5a) facing the supply line (3) and being able to come into abutment with a sealing seat (7) with spring loading and wherein a second surface (9) of the closure element (5a) facing away from the supply line (3) and a pressure chamber (10) limited, and comprising a solenoid valve (26) having a hydraulic connection (1 1) between the supply line (3) and the pressure chamber (10) controls, with the hydraulic Verbin (1 1) from the first surface (6) to the second surface (9), characterized in that the hydraulic connection (1 1) via an inlet opening (13) opens into the pressure chamber (10), wherein the inlet opening ( 13) by means of a closing body (14) of the solenoid valve (26) is closable.

2. Apparatus according to claim 1, characterized in that the pressure chamber (10) has a drain opening (16) which by means of a second closing body (17) of the solenoid valve (26) is closable.

3. A device according to claim 2, characterized in that the closing body (17) does not close the inlet opening (13) when the outlet opening (16) is closed.

4. Apparatus according to claim 2 or 3, characterized in that the second closing body (17) with closed inlet opening (13), the drain opening (16) does not close.

5. Device according to one of claims 2 to 4, characterized in that the closing body (14) and the second closing body (17) on a push rod (18) of the solenoid valve (26) are arranged.

6. Device according to one of claims 2 to 5, characterized in that the second closing body (33) comprises a check valve (34) or that a drain port T comprises a check valve (28).

7. Device according to one of the preceding claims, characterized in that the closure element (5a) comprises a hollow cylindrical piston (4) and that the hollow cylindrical piston (4) on a front side, which faces the pressure chamber (10), a cup-shaped sleeve ( 5), wherein the cup-shaped sleeve (5) forms the second surface (9) of the closure element (5a) and wherein the cup-shaped sleeve (5) has a recess as an inlet opening (13) through which the push rod (18) with the closing body (14) attacks.

8. Device according to one of the preceding claims, characterized in that the inlet opening (13) when not actuated solenoid valve (26) through the

Closing body (14) is closed.

9. Device according to one of claims 7 to 8, characterized in that the closing body (14) has a conically or spherically shaped portion (19) which is provided for sealing engagement with the inlet opening (13), and a cylindrically shaped portion ( 20), which is guided on the inner peripheral surface of the hollow cylindrical piston (4), wherein a conically or spherically shaped portion (19) extending flattening (21) of the cylindrically shaped portion (20) has a hydraulic connection between the supply line (3) and Inlet opening (13) allows.

10. Device according to claims 5 and 7, characterized in that the hydraulic connection (1 1) is a between the first surface (6) and the second surface (9) extending stepped bore, wherein the closing body (14) separated from the Push rod (18) is arranged and held by means of the stepped bore formed by the shoulder (27) in the stepped bore.