Control unit for a vehicle

Abstract

Operating unit for a vehicle, in particular a human-machine interface for e.g. a vehicle component such as a heating, ventilation and / or air conditioning system, an infotainment system or a navigation device, with - a housing (12) having a front wall (13) formed by a front panel (14) and a rear wall (28), - at least one depressible operating button (18, 20, 22) arranged on the front panel (14), which has a button body (44) guided on the front panel (14) and reversibly depressible along a movement axis (45), which is arranged in a receiving space (46) extending through the front panel (14) from its outer side (48) to its inner side (50) with an opening (52) on the inner side (50) of the front panel (14), - a switch (32) associated with the at least one operating button (18, 20, 22) with a switch housing (30) having an upper side (40) facing the inside (50) of the front panel (14), and with a reversibly depressible plunger (42) projecting over the upper side (40) of the switch housing (30) for triggering a switching function of the switch (32) and - a support element (24) on which the switch housing (30) is arranged, - wherein the front panel (14) rests on its inner side (50) in the area around the opening (52) of the receiving space (46) on the switch housing (30) and the plunger (42) projects into the opening (52) on the inner side (50) of the front panel (14) and rests against the button body (44) of the operating button (18, 20, 22), characterized in that - that the front panel (14) is free from contact with both the support element (24) and the rear wall (28), wherein the front panel (14) is connected to the support element (24) or to the rear wall (28) by means of a connecting element (56) with the front panel (14) resting on the switch housing (30).

Description

The invention relates to an operating unit for a vehicle and, in particular, to a human-machine interface for, for example, a vehicle component such as, for example, a heating, ventilation and / or air conditioning system, an infotainment system, a navigation device or the like.Control units for vehicles typically also have, inter alia, pressable control buttons, each of which is assigned a switch arranged in the housing of the control unit behind the front panel (see, for example, DE 197 04 253 A1 and DE 20 2006 020 058 U1). Due to the manufacturing tolerances of the various components of the operating unit such as the carrier element, in particular the printed circuit board on which the switch is arranged, the switch housing, the soldering of the connections of the switch housing to the contact pads of the carrier element or the printed circuit board, the response behavior of the switches of a plurality of operating keys of an operating unit can be significantly different, which is undesirable.DE 201 02 441 U1 describes an operating unit in which the front panel bears against the housing of a rotary actuator arranged behind it, the rotary shaft of which is led through an opening in the front panel and which carries a rotary knob on the front side thereof.U.S. Pat. No. 6,347,077 B1 describes a form of mounting a printed circuit board, on which the switches assigned to the keys of a keyboard are located, in the housing of a laptop.Furthermore, from DE 10 2010 020 903 A1 an operating unit according to the preamble of claim 1 is known.It is the object of the invention to provide an operating unit for a vehicle in which the chain of mutually cooperating manufacturing tolerances of different components of the operating unit is shortened.To achieve this object, the invention proposes an operating unit for a vehicle, in particular a human-machine interface for a vehicle component, for example, such as a heating, ventilation and / or air conditioning system, an infotainment system, a navigation device or the like, wherein the operating unit is provided witha housing which has a front wall formed by a front panel and a rear wall,at least one pressable operating button arranged on the front panel, which button has a button body guided on the front panel and pressable reversibly along an axis of movement, which button body is arranged in a receiving space extending through the front panel from its outer side to its inner side, with an opening on the inner side of the front panel,a switch assigned to the at least one operating button, having a switch housing which has an upper side facing the inside of the front panel, and having a plunger which protrudes beyond the upper side of the switch housing and can be pressed down reversibly for triggering a switching function of the switch, anda carrier element on which the switch housing is arranged,wherein the front panel rests on the switch housing on its inner side in the region around the opening of the receiving space and the plunger projects into the opening on the inner side of the front panel and bears against the button body of the operating button, andwherein the front panel is free of contact with both the carrier element and the rear wall, wherein the front panel is connected to the carrier element or to the rear wall by means of a connecting element, with the front panel resting on the switch housing.Accordingly, the invention proposes that the front panel forming the front wall of the housing of the control unit be arranged on its inner side facing into the housing, resting on the switch housing of the switch assigned to a control button, whereby the distance of the inner side of the front panel from the carrier element carrying the switch is determined only by the protrusion of the plunger of the switch, the switch housing with the electrical connection elements, the thickness of the solder and the thickness of the copper contact surface of the carrier element. In particular, this distance no longer includes a possible manufacturing tolerance of the front panel, since, unlike usual, it rests exclusively on the switch housing, namely on its inner side in the region around the button body of the operating button.The control unit according to the invention has a housing which is provided with a front panel on its front wall and has a rear wall facing away from the front wall. A carrier element for a switch is located within the housing, wherein the carrier element is typically designed as a printed circuit board. At least one push-down control button is arranged in the front panel. The operating button has a button body which is movable along an axis of movement in the direction of the carrier element and back, i.e. reversibly depressed. The button body is accommodated and guided in an accommodation space of the front panel, wherein the accommodation space is open both to the outside of the front panel and to the inside of the front panel through an opening. On the outside of the front panel, the front side of the operating button is located in this opening, which usually has a symbol.In the assembled state, the inner side of the front panel now lies in the region around the opening of the receiving space on the upper side of the switch housing, which faces the inner side of the front panel. The connection of the front panel to, for example, that of the carrier element and / or the rear wall of the housing is designed without direct contact of the front panel with both the carrier element and the rear wall. The front panel is secured in or on the housing against unintentional detachment, while the button body is secured, for example, on the front panel against unintentional detachment.According to the invention, the front panel is free from contact with both the carrier element and the rear wall.According to an alternative development of the invention, the front panel is braced with the rear wall by means of, for example, an elastic connecting element. In this further development of the invention, the rear wall is thus connected to the front panel in an elastically prestressed manner. This clamping of the front panel and rear wall thus leads to a certain clamping of the switch housing between the inner side of the front panel and the carrier element. When the operating button is pressed down, the spacer element then acts as a counterpressure point and supports / stiffens the carrier element, which, as already mentioned above, is typically a comparatively thin printed circuit board.However, the connection of the front panel and the rear wall or carrier element can also alternatively be effected by a (cured) adhesive layer (adhesive bead) in which the front panel is embedded without having contact with the rear wall or with the carrier element. Alternatively, a screw connection is also possible or else a latching / clipping is possible, wherein in all these connection variants, whether or not they are associated with a bracing / clamping of the switch housing between the front panel and the carrier element, it applies that the front panel bears against the switch housing.In an expedient embodiment of the invention, it can be provided that the carrier element is arranged in the housing and that a spacer element is arranged between the carrier element and the rear wall of the housing in alignment with the switch housing and in extension of the movement axis of the key body. According to the invention, the switch housing is thus enclosed between the front panel and the carrier element. Arranged in alignment with the switch housing in the extension of the movement axis, a spacer element is located between the carrier element and the rear wall of the housing as a counterpressure point and to support the carrier element when a pressing force is exerted for pressing down the operating button.The invention is explained in more detail below on the basis of an exemplary embodiment and with reference to the drawing. In detail, the following show: FIG. 1 shows a front view (perspective) of an operating unit, FIG. 2 shows a section through the operating unit according to II-II of FIG. 1, wherein the structure of operating units typically and thus belonging to the prior art is shown in this sectional view, and FIG. 3 shows a section through the operating unit according to II-II of FIG. 1 with the structure according to the invention of the operating unit with a shortened closing dimension tolerance chain.According to FIG. 1, an operating unit 10 has a housing 12, the front wall 13 of which is formed by a front panel 14, on which, for example, a display 16 and operating buttons 18, 20 and 22 are arranged. Further, in particular differently configured, operating elements such as, for example, a rotary actuator or the like can likewise be arranged on the front panel 14. Within the housing 12 is a support element 24 for various electrical and electronic components. This support member 24 is typically a printed circuit board 26 and the housing 12 further includes a back wall 28.The typical design of the operating unit 10 is shown in partial section in FIG. 2. In this case, the front panel 14 contacts the carrier element 24, against which it bears, as shown in FIG. 2. On the carrier element 24 is the housing 30 of a switch 32 which has electrical connection contact pads 34 on, for example, its underside, which are soldered onto the contact pads 38 of the carrier element 24 by means of a solder layer 36. A plunger 42 protrudes from the upper side 40 of the switch housing 30 facing away from the carrier element 24, which plunger is arranged in a reversibly pressable manner in the switch housing 30 in order to exert a switching function of the switch 32. The button body 44 of the operating button 22 sits on this plunger 42, wherein the operating button 22 itself is guided on the front panel 14 so as to be pressable along the movement axis 45 and is also secured there against falling out, as is conventional per se. By the restoring force of the plunger 42, the button body 44 is moved back again into the initial / rest position shown in FIG. 2 along the movement axis 45 when the operating button 22 is released. The button body 44 is located in a receiving space 46 of the front panel 14, which connects its outer side 48 to its inner side 50, wherein a receiving space opening 52 is formed on the inner side, into which the plunger 42 of the switch 32 projects.The components relevant for the closing dimension tolerance chain 54 (see the double arrow) and in particular relevant component manufacturing tolerances are the plunger 42, the height of the switch housing 30, the "thickness" and position of the electrical connection contact pads 34, the thickness of the solder layers 36 and the thickness of the contact pads 38.For the "shortening" of the previously mentioned closing dimension tolerance chain 54 in this respect, a construction of the operating unit 10 is now proposed according to the invention, as is shown in section in FIG. 3.In contrast to the arrangement according to FIG. 2, the structure according to FIG. 3 is characterized by the placement of the front panel 14 on its inner side 50 on the upper side 40 of the switch housing 30. the front panel 14 is free from direct contact with both the carrier element 24 and the rear wall 28. the rear wall 28 is realized with the front panel 14 by a connection element which is shown schematically at 56 and is in particular elastic and is subject to tension, as a result of which the rear wall 28 is resiliently braced with the front panel 14. Below the carrier element 24 there is a spacing element 58 in extension of the movement axis 45 which forms a counterpressure point upon actuation of the operating button 22. The closing dimension tolerance chain 54 is now solely dependent on the plunger 42, which significantly improves the compliance with the same response behavior of the plurality of operating keys 18, 20, 22.LIST OF REFERENCE CHARACTERS10 Operating unit 12 Housing of the operating unit 13 Front wall of the housing 14 Front panel of the housing 16 Display 18 Operating button 20 Operating button 22 Operating button 24 Carrier element 26 Printed circuit board 28 Rear wall of the housing 30 Switch housing 32 Switch 34 Connection contact fields of the switch 36 Solder layer 38 Contact fields for the connection contact fields of the switch 40 Upper side of the switch housing 42 Plunger 44 Button body 45 Movement axis of the button body 46 Accommodation space for the button body in the front panel 48 Outer side of the front panel 50 Inner side of the front panel 52 Accommodation space opening on the inner side of the front panel 54 Closing dimension tolerance chain 56 Connecting element between the front panel and the rear wall 58 Spacing element

Claims

Operating unit for a vehicle, in particular a human-machine interface for a vehicle component such as, for example, a heating, ventilation and / or air conditioning system, an infotainment system or a navigation device, having - a housing (12) which has a front wall (13) formed by a front panel (14) and a rear wall (28), - at least one suppressible operating button (18, 20, 22) arranged on the front panel (14) and which has a button body (44) which is guided on the front panel (14) and can be reversibly suppressed along an axis of movement (45) and is arranged in a receiving space (46) which extends through the front panel (14) from the outer side (48) thereof to the inner side (50) thereof and has an opening (52) on the inner side (50) of the front panel (14), - one of the at least one operating buttons (18, 20, 20, Switch (32) assigned to the switch (22), having a switch housing (30) which has an upper side (40) facing the inner side (50) of the front panel (14), and having a plunger (42) which projects beyond the upper side (40) of the switch housing (30) and can be reversibly pressed down for triggering a switching function of the switch (32), and having a carrier element (24) on which the switch housing (30) is arranged, - the front panel (14) resting on the switch housing (30) on its inner side (50) in the region around the opening (52) of the receiving space (46), and the plunger (42) protruding into the opening (52) on the inner side (50) of the front panel (14) and resting on the button body (44) of the operating button (18, 20, 22), characterized in that, the front panel (14) being free of contact with both the carrier element (24) and the rear wall (28), wherein the front panel (14) is connected by means of a connecting element (56) to the carrier element (24) or to the rear wall (28), with the front panel (14) resting against the switch housing (30).Operating unit according to Claim 1, characterized in that the connecting element (56) is designed as an adhesive layer or screw or latching or clipping unit or as a connecting hold-down device or as a connecting elastic connecting element which can be subjected to tension.Operating unit according to Claim 1 or 2, characterized in that the carrier element (24) is arranged in the housing (12), and in that a spacer element (58) is arranged between the carrier element (24) and the rear wall (28) of the housing (12) in alignment with the switch housing (30) and in extension of the movement axis (45) of the button body (44).

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