Venting device for an actuating device of a switching element

Abstract

The invention relates to a venting device (10) for an actuating device (100) of a switching element, in particular a self-holding switching element, of a motor vehicle, comprising a venting valve (20), wherein the actuating device (100) has a piston chamber (110) with a hydraulic supply unit. The venting valve (20) is arranged in the direction of a vertical axis (120) of the motor vehicle above the piston chamber (110) and at an upper point of the hydraulic supply unit, and has a longitudinal axis (50) which, when the venting valve (20) is arranged as intended, extends substantially parallel to the vertical axis (120) of the motor vehicle. The venting valve (20) has a valve housing (22) with a venting chamber (24) arranged therein, which has at least one inlet opening (26) with a sealing seat (30) which is closed by a ball (32) when the venting valve (20) is closed.A spring element (34) is arranged within the vent chamber (24), which is supported on the ball (32) and at least indirectly on the valve housing (22). The sealing seat (30) has a funnel shape with an acute opening angle (40).

Description

[0001] The invention relates to a venting device for an actuating device of a switching element, in particular a self-holding switching element, of a motor vehicle.

[0002] In current hydraulic systems, hydraulic piston chambers are vented via vent orifices. When depressurized, the hydraulic oil slowly flows out of the hydraulic piston chamber due to the open orifice. Depending on the time between switching operations, undefined fill levels are present in the hydraulic piston chamber, making reproducible actuation times impossible. To contain efficiency losses, pressure control with constant pressure is necessary.

[0003] This can be particularly problematic when using self-locking shift elements. Self-locking means that no force is required to hold the shift element in a stationary state (engaged or disengaged), but rather, a mechanical lock or other self-locking mechanism is provided. For example, the plates of conventional multi-plate shift elements in automatic transmissions are permanently subjected to pressure in the gears in which they are engaged.

[0004] DE 38 30 829 A1 discloses a hydraulically actuated shifting device, in particular a multi-disk clutch or brake for motor vehicle transmissions that can be shifted under load, comprising a pressurizable working piston arranged in a working cylinder. The working cylinder is connected to a vent valve. This vent valve automatically discharges the air present in the working cylinder during each shifting operation. The vent valve has a spring-loaded check valve that blocks the direction of the working cylinder.

[0005] An object of the invention is to provide an improved venting device for an actuating device of a switching element, in particular a self-holding switching element, of a motor vehicle.

[0006] The above-mentioned problem is solved by the features of the independent claim.

[0007] Advantageous embodiments and advantages of the invention emerge from the further claims, the description and the drawing.

[0008] According to one aspect of the invention, a venting device for an actuating device of a switching element, in particular a self-holding switching element, of a motor vehicle is proposed, comprising a venting valve, wherein the actuating device has a piston chamber with a hydraulic supply device. The venting valve is arranged above the piston chamber in the direction of a motor vehicle vertical axis, and in particular at an uppermost point of the hydraulic supply device, viewed in the direction of a motor vehicle vertical axis, and has a longitudinal axis which, when the venting valve is arranged as intended, extends substantially parallel to the motor vehicle vertical axis.The ventilation valve has a valve housing with a ventilation space arranged therein, which has at least one inlet opening with a sealing seat that is closed by a ball in the closed state of the ventilation valve. A spring element is arranged within the ventilation space, which is supported on the ball and at least indirectly on the valve housing. The sealing seat has a funnel shape with a sharp opening angle.

[0009] The proposed venting device vents the hydraulic piston chamber as soon as it is pressurized with hydraulic oil and simultaneously prevents it from running dry in a depressurized state. The hydraulic piston chamber is pressurized with hydraulic oil to control the switching element. Between switching operations, the hydraulic oil slowly drains through a vent orifice, or the fill level in the hydraulic piston chamber decreases over time. The venting device prevents this, ensuring that the hydraulic piston chamber remains filled with hydraulic oil regardless of the time of the last switching operation, enabling reproducible control.

[0010] The sealing seat of the vent valve is designed with a slope, for example, at 60 degrees, to ensure centering of the spring element-ball combination. When used in conjunction with a self-retaining switching element, such as a claw switch, no pressure control is required, since pressure or oil volume is only required during the switching process.

[0011] In the vent valve, the ball acts as the closing element of the vent valve, supporting the spring element, which is supported on the other side by the valve housing. This eliminates the need for the spring element to be guided through the valve housing on its outer circumference, and the venting chamber of the valve housing is not limited in size. This enables faster venting and improved response of the switching element.

[0012] The proposed venting device can advantageously prevent the hydraulic piston chamber from running dry.

[0013] The opening pressure of the vent valve can be conveniently adjusted by adjusting the spring stiffness of the spring element. For example, an opening pressure of 0.4 bar to 0.7 bar can be selected.

[0014] The ventilation function remains fully intact.

[0015] This advantageously results in greater flexibility in the orifice diameter or the venting speed and, depending on this, the maximum pressure or the loss of efficiency of the actuating device.

[0016] According to an advantageous embodiment of the venting device, the sealing seat can have a funnel shape with an opening angle of at most 80 degrees, preferably at most 70 degrees, particularly preferably at most 60 degrees. This advantageously ensures centering of the spring element-ball combination. This results in faster venting and improved response of the switching element.

[0017] According to an advantageous embodiment of the venting device, an outflow opening of the venting chamber can be arranged along the longitudinal axis opposite the inflow opening. This advantageously eliminates the need for flow redirection during venting. The vent valve creates less pressure loss.

[0018] According to an advantageous embodiment of the venting device, the outflow opening of the venting chamber can be arranged at the top, in the direction of the vehicle's vertical axis, and the inflow opening at the bottom. This allows for better air removal when venting the actuating device.

[0019] According to an advantageous embodiment of the venting device, an outflow cross-section of the outflow opening can be arranged radially centrally on an outflow side of the vent valve. This advantageously eliminates the need for flow redirection during venting. The vent valve generates less pressure loss because the full outflow opening is available as the outflow cross-section.

[0020] According to an advantageous embodiment of the venting device, the outflow cross-section can be arranged radially within the spring element. The vent valve generates less pressure loss because the full outflow opening is available as the outflow cross-section.

[0021] According to an advantageous embodiment of the venting device, the ball can be arranged along the longitudinal axis above the sealing seat. This allows for better air removal when venting the actuating device.

[0022] According to an advantageous embodiment of the venting device, the spring element can be designed as a spiral spring. A spiral spring can be securely guided by the ball as the closing element of the vent valve and thus requires no additional guidance through the valve housing.

[0023] According to an advantageous embodiment of the venting device, the spring element can be guided along the longitudinal axis of the ball. This eliminates the need for the spring element to be guided through the valve housing on its outer circumference, and the valve housing's venting chamber is not restricted in size. This allows for faster venting and improved response of the switching element.

[0024] According to an advantageous embodiment of the venting device, the venting valve can be arranged in the actuating device via a press fit. The venting valve can thus be secured via the press fit and requires no additional securing elements.

[0025] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and combine them into further meaningful combinations.

[0026] Showing: Fig. 1 a schematic sectional view of an actuating device of a switching element, in particular a self-holding switching element, of a motor vehicle, with a vent valve as a venting device according to an embodiment of the invention; Fig. 2 the vent valve Fig. 1 in a longitudinal section; and Fig. 3 the vent valve Fig. 1, mounted in the actuating device in a longitudinal section.

[0027] In the figures, identical or similar components are designated by the same reference numerals. The figures are merely examples and are not to be construed as limiting.

[0028] Fig. 1 shows a schematic sectional view of an actuating device 100 of a switching element, in particular a self-holding switching element, of a motor vehicle, with a vent valve 20 as venting device 10 according to an embodiment of the invention.

[0029] The actuating device 100 has a piston chamber 110, circular in cross-sectional view, with a hydraulic supply device (not shown). A hydraulic piston 111 is arranged inside the piston chamber 110. The space between the hydraulic piston 111 and the inner wall of the piston chamber 110 is filled with hydraulic oil 102. The hydraulic supply device is hydraulically connected to the piston chamber 110 via a combined inlet / outlet 112.

[0030] The piston chamber 110 has a vent opening 116, at which a venting device 10 with a vent valve 20 is arranged, which is arranged in the direction of a motor vehicle vertical axis 120 above the piston chamber 110 and at an upper point of the hydraulic supply device.

[0031] A housing 114, which forms a closure of the piston chamber 110 to the outside (see Fig. 3), is omitted from the schematic representation.

[0032] The vent valve 20 has a longitudinal axis 50 which, when the vent valve 20 is arranged as intended, extends substantially parallel to the vertical axis 120 of the motor vehicle.

[0033] Fig. 2 shows the vent valve 20 after Fig. 1 in a longitudinal section.

[0034] The vent valve 20 has a valve housing 22 with a vent chamber 24 arranged therein. The vent chamber 24 has an inlet opening 26 with a sealing seat 30, which, when the vent valve 20 is closed, is sealed with a ball 32 as a closing element. The ball 32 is arranged along the longitudinal axis 50 above the sealing seat 30.

[0035] A spring element 34 is arranged within the venting chamber 24 and is supported on the ball 32 and at least indirectly on the valve housing 22. The spring element 34 is designed as a spiral spring and is guided by the ball 32 in the direction of the longitudinal axis 50. For this purpose, the spring element 34 is arranged on a guide seat 38 on the ball 32.

[0036] The sealing seat 30 has a funnel shape with an acute opening angle 40. The funnel shape can have an opening angle 40 of at most 80 degrees, preferably at most 70 degrees, particularly preferably at most 60 degrees.

[0037] An outflow opening 28 of the venting chamber 24 is arranged along the longitudinal axis 50 opposite the inflow opening 26. The outflow opening 28 of the venting chamber 24 is arranged at the top in the direction of the motor vehicle vertical axis 120, and the inflow opening 26 is arranged at the bottom.

[0038] An outflow cross-section 29 of the outflow opening 28 is arranged radially centrally on an outflow side 36 of the vent valve 20. The outflow cross-section 29 is arranged radially within the spring element 34.

[0039] The vent valve 20 closes the inlet opening 26 via the ball 32 under spring pressure from the spring element 34, thus preventing the hydraulic piston chamber 110 from running dry in a depressurized state. When the piston chamber 110 is pressurized, the ball 32 is lifted against the spring element 34 by the hydraulic oil pressure and vents the hydraulic piston chamber 110. The opening pressure can be continuously adjusted via the spring stiffness. The venting speed and the maximum permissible hydraulic pressure can be adjusted via the bore diameter of the inlet opening 26 into the vent chamber 24 of the valve housing 22.

[0040] Fig. 3 shows the vent valve 20 after Fig. 1, mounted in the actuating device 100 in a longitudinal section.

[0041] The vent valve 20 is mounted in a bore 118 of the housing 114 of the piston chamber 110. The valve housing 22 can be secured in the bore 118 via a press fit and thus requires no additional securing elements.

[0042] When the piston chamber 110 is vented, the air flows through the vent opening 116 in the housing 114 through the inlet opening 26 of the vent valve 20 if there is sufficient pressure in the piston chamber 110 to overcome the spring force of the spring element 34 so that the ball 32 lifts off its sealing seat 30. When the ball 32 is lifted off the sealing seat 30, the air enters the vent chamber 24 of the valve housing 22 and through the outlet opening 28 of the valve housing 22 and through the bore 118 of the housing 114 to the outside. List of reference symbols 10 Ventilation device 20 vent valve 22 valve housing 24 Ventilation room 26 Inlet opening 28 Outlet opening 29 Outlet cross-section 30 Sealing seat 32 balls 34 spring element 36 Outflow side 38 Management seat 40 opening angle 50 Longitudinal axis 100 Actuating device 102 Hydraulic oil 110 piston chamber 111 hydraulic pistons 112 Inlet / Outlet 114 housings 116 Vent opening 118 Hole vent valve 120 vehicle vertical axis QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] DE 38 30 829 A1

[0004]

Claims

[1] Ventilation device (10) for an actuating device (100) of a switching element of a motor vehicle, with a vent valve (20), wherein the actuating device (100) has a piston chamber (110) with a hydraulic supply device, wherein the vent valve (20) is arranged in the direction of a motor vehicle vertical axis (120) above the piston chamber (110) of the hydraulic supply device, and has a longitudinal axis (50) which, when the vent valve (20) is arranged as intended, extends substantially parallel to the vertical axis (120) of the motor vehicle, wherein the vent valve (20) has a valve housing (22) with a vent chamber (24) arranged therein, which has at least one inlet opening (26) with a sealing seat (30) which is closed with a ball (32) when the vent valve (20) is in the closed state, wherein a spring element (34) is arranged within the venting chamber (24), which is supported on the ball (32) and at least indirectly on the valve housing (22), wherein the sealing seat (30) has a funnel shape with an acute opening angle (40). [2] Ventilation device according to claim 1, wherein the sealing seat (30) has a funnel shape with an opening angle (40) of at most 80 degrees, preferably at most 70 degrees, particularly preferably at most 60 degrees. [3] Ventilation device according to claim 1 or 2, wherein an outflow opening (28) of the ventilation space (24) is arranged along the longitudinal axis (50) opposite the inflow opening (26). [4] Ventilation device according to claim 3, wherein the outflow opening (28) of the ventilation chamber (24) is arranged at the top in the direction of the motor vehicle vertical axis (120) and the inflow opening (26) is arranged at the bottom. [5] Ventilation device according to claim 3 or 4, wherein an outflow cross-section (29) of the outflow opening (28) is arranged radially centrally of an outflow side (36) of the vent valve (20). [6] Ventilation device according to claim 5, wherein the outflow cross-section (29) is arranged radially inside the spring element (34). [7] Ventilation device according to one of the preceding claims, wherein the ball (32) is arranged in the longitudinal axis (50) above the sealing seat (30). [8] Ventilation device according to one of the preceding claims, wherein the spring element (34) is designed as a spiral spring. [9] Ventilation device according to one of the preceding claims, wherein the spring element (34) is guided in the direction of the longitudinal axis (50) by the ball (32). [10] Ventilation device according to one of the preceding claims, wherein the vent valve (20) can be arranged in the actuating device (100) via a press fit.

Images