Locking device for a motor vehicle hood, and method

Abstract

A locking device and method for locking the locking device includes a lock for a door or a hatch for a hood of a motor vehicle. The lock having includes a locking mechanism that has a rotary latch and at least one pawl for blocking the rotary latch. The locking device includes a drive which allows the locking mechanism to be moved in such a way that a door gap or hatch gap can be narrowed in the closed state of the door or hatch. The lock is an electric lock that includes an electric drive which allows the locking mechanism to be brought into the main blocking position of the locking mechanism and/or allows the lock to be opened.

Claims

1. A locking device for a door or hatch of a motor vehicle, the locking device comprising: a locking mechanism having a catch and a first pawl for blocking the catch; and a motorized drive that is a closing aid, the drive including a driving wheel from which an eccentrically arranged bolt projects, a rocking lever defining a slot into which the bolt extends for moving the locking mechanism, and a second pawl mounted on the rocker arm; and a latch housing to which the locking mechanism is mounted, wherein the second pawl is engageable with an outside of the latch housing to retain the latch housing during movement of the rocking lever for movement of the latch housing with the rocking lever, whereby the locking mechanism is displaced in relation to a fixed base element.

2. The locking device according to claim 1, wherein the locking mechanism can only be moved from a pre-ratchet to a main ratchet position by the closing aid.

3. The locking device according to claim 1, wherein the rocker is pivotally connected to the base element.

4. The locking device according to claim 1, wherein the rocker and the latch housing are connected to the base housing in such a way that they pivot around the same axis.

5. The locking device according to claim 1, wherein the pawl is pivotally mounted on the rocker.

6. The locking device according to claim 1, wherein the eccentrically arranged bolt carries out circular movements within the slot that are initiated by the motorized drive, in order to pivot the rocker and with it the latch housing around the axis in relation to the base element.

7. The locking device according to claim 1, wherein the latch housing is connected to the base element and pivotally around an axis.

Description

(1) The Figures show the following

(2) FIG. 1: Latch arrangement in the locked state (main ratchet position);

(3) FIG. 2: Perspective view of latch;

(4) FIG. 3: View from top of latch;

(5) FIG. 4: Installed latch and hood;

(6) FIG. 5: Enlarged view of a section when catch makes contact with stop of the latch;

(7) FIG. 6: Initial closing of hood with remaining gap;

(8) FIG. 7: Continuation of locking process;

(9) FIG. 8: Complete locking of hood;

(10) FIG. 9: Initial opening of hood;

(11) FIG. 10: Continuation of opening of hood;

(12) FIG. 11: Hood and blocking of catch in pre-ratchet position;

(13) FIG. 12: Complete opening of hood;

(14) FIG. 13: Locking device with open hood in example;

(15) FIG. 14: Object of FIG. 13 with closed hood.

(16) FIG. 1 illustrates the design of a locking device for a door or hatch of a motor vehicle. The locking device contains a latch with a locking mechanism comprising catch 1 and pawl 2. The catch 1 can be locked in a closed position with the pawl 2, as shown in FIG. 1. The pawl 2 is pivotally mounted on a latch plate 3 by means of an axis 5. The pawl 2 is pivotally mounted on the latch plate 3 by means of its axis 5. The arrangement can contain a frame box instead of a latch plate 3. In the present arrangement, a latch plate 3 is, however, preferred for reasons of space which in contrast to a frame box does not contain any side walls. For reasons of stability, the latch plate 3 or the frame box are preferably made of metal. The pawl 2 and/or catch 1 are preferably also wholly or partly made of metal.

(17) Using a drive 6, the locking mechanism comprising catch 1 and pawl 2 can be moved in such a way that a door gap or hatch gap can be reduced. For this purpose, the drive 6 contains, in particular, an electric motor 7 and a worm 8 connected to the shaft of the motor. The motor 7 can effect a pivoting movement of the worm 8. A pivoting movement of the worm 8 produces a pivoting movement of a wheel 10 by means of a, preferably provided, multi-stage gear system 9. A bolt 11 extends perpendicularly from the wheel 10. The bolt 11 is fixed to the wheel 10. The bolt 11 is mounted at a distance from the rotation centre of the wheel 10 and is thus eccentrically arranged. The bolt 11 extends into a slot 12 of a pivotally mounted lever or rocking lever 13. The rocking lever 13 is pivotally mounted by means of an axis or shaft 5. Rotation of the wheel 10 thus causes the rocking lever 13 to be displaced.

(18) The lever 10 and the latch plate 3 are connected to the shaft 5. Pivoting of the lever 13 thus results in synchronous pivoting of the latch plate 3.

(19) When viewed from the shaft 5, the latch plate 3 and rocking lever 13 extend in the same direction and, preferably, in the direction of the drive 6 in order to keep the required installation space to a minimum. The rocking lever 13 extends past the latch plate 3 and, in particular, past the infeed section of the latch plate 3, i.e. past the area entered by the locking bolt when an associated door or hatch is closed. As a result, favorable lever ratios are provided so that the rocking lever 13 can be pivoted with little electric power in order to reduce a gap of a door or hatch.

(20) In addition, the locking device contains a first plate 14 shown in FIGS. 2 and 3. For reasons of stability, the opposite side preferably contains a second plate 15. The two plates 14 and 15 are pivotally mounted on the axis or shaft 5. For reasons of stability, the one or two plates 14 and 15 are preferably made of metal. Using bent tabs 16 containing holes, the one or two plates 14 and 15 are secured with notches or bolts on, for instance, a door, hatch or a motor vehicle body. Where one or two plates 14 and 15 are mounted on the motor vehicle body 17, as shown in FIG. 4, the associated locking bolt 18 (see FIG. 4) is mounted on the door or hatch 19. FIG. 4 shows a fixing on a front bonnet of a motor vehicle. The drive 6 is mounted on the plate 15. One of the plates 14 or 15 preferably also serves as a fixing for the drive in order to keep the number of parts to a minimum.

(21) The locking device contains a web-shaped stop 20, pivotally secured to the plate 14 by means of an axis or shaft 21. In particular, a bolt 22 extends perpendicularly from plate 14 and is able to restrict a pivoting movement of the stop 20 (see FIGS. 2 and 3). The web-shaped stop 20 contains a preferably bent tab 23 that can be moved against the bolt 22 by pivoting in order to prevent a continuation of a respective pivoting movement when reaching bolt 22, as shown in FIGS. 1, 2 and 3.

(22) Viewed from the axis or shaft 21, a shackle 24 does for instance extend, serving to control movement of stop 20. Together with stop 20, the shackle 24 is more or less U-shaped in one embodiment. Generally the shackle 24 rests against the bolt 11. When the wheel 10 is pivoted, the shackle 24 is also moved because of the bolt 11. Displacement of the shackle 24 causes a respective synchronous movement of stop 20.

(23) Stop 20 not only serves as a stop for the catch 1 but also as a stop for rocker arm 13 when the locking bolt 18 engages in the latch. In order to ensure that the stop 20 also serves as a stop for rocking lever 13 in a preferred embodiment, the stop 20 and the rocking lever 13 contain suitable bent tabs 25 and 26. Once the locking bolt 18 engages in the latch, the bent tab 25 of the rocking lever 13 comes into contact with the bent tab 26 of stop 20 as the enlarged section of FIG. 5 shows. FIG. 5 also shows one end of an arm of the catch 1 coming in contact with the end of the stop 20. This embodiment thus offers two options of transferring a load onto plate 14 during closing, thus protecting the drive 6.

(24) The latch also contains a triggering lever 27 also pivotally mounted on the axis or shaft S. The triggering lever 27 is actuated by a Bowden cablenot shown. By actuating the Bowden cable, the pawl 2 is moved out of its engaged position, allowing a door or hatch to be opened. The triggering lever 27 can contain a hook 28 for engaging the Bowden cable.

(25) FIG. 3 shows, for instance, that the axes/shafts can contain springs for moving the pivotable components by the force of the springs, as for instance the catch 1 from a closed towards an open position.

(26) FIG. 6 shows the situation after the locking bolt 18 has engaged in the latch. One arm of the catch 1, the so-called load arm, rests on stop 20. The tab 25 of the rocking lever 13 rests on the tab 26 of the stop 20. The catch 1 has been locked by the pawl 2 and is in the main ratchet position. A gap 29 remains between the hood 19 and the body 17 of the motor vehicle. The wheel 10 of the drive 6 is in its initial position. In the initial position the bolt 11 is located in one embodiment above the centre of rotation of the wheel 10.

(27) In one embodiment it is, however, also possible for the catch 1 to be initially only locked in the pre-ratchet position shown in FIG. 10 as a result of the locking bolt 18 engaging. Only once stop 20 is moved out of its stop position can the catch be pivoted into the main-ratchet position by means of an electric drive and, in particular, an electric motor 7 and a mechanismnot shown. In this embodiment, the gap 29 can be reduced to 2-4 mm as a result of reaching the main-ratchet position.

(28) In order to reduce the gap 29 further, starting from the main-ratchet position of the locking mechanism, the wheel 10 is turned clockwise with the aid of the drive 6. As a result, the bolt 11 moves within the slot 12 as a result of a quarter turn first from the one left side of the slot to the other right side of the slot, as apparent when comparing FIGS. 6 and 7. By turning in clockwise direction, the stop 20 is pivoted with the aid of the shackle 24 in clockwise direction out of its stop position. Once the stop 20 has been moved out of its stop position, the rocking lever 13 and thus also the latch plate 3 can be pivoted clockwise around its axis or shaft 5 in order to reduce the gap 29 further in order to finally provide a gapless contact between bonnet 19 and motor vehicle body 17 at the front, as shown in FIG. 8. If wheel 10 is turned further in clockwise direction and if the wheel 10 thus carries out an approx. 180 rotation, the gap finally disappears, as shown in FIG. 8.

(29) The position of the wheel 10 is, for instance, determined with the aid of a micro switch 30. Once the wheel 10 has reached the position shown in FIG. 8 this is sensed by the micro switch 30, stopping the drive. Alternatively or in addition, a current detector (current for electric motor) can determine the reached position, allowing suitable switching. One or several micro switches can be provided in order to determine, for instance, the position of catch 1 and/or pawl 2 and to control blocking and/or opening of the locking mechanism depending on said position.

(30) FIGS. 9 to 12 show the opening of the hood 19. First, the pawl 2 is moved out of its engaged position as shown in FIG. 9. This is achieved by actuating the triggering lever 27, which for this purpose is pivoted clockwise around its axis or shaft 5. The catch 1 can then be pivoted counterclockwise resulting in the hood 19 being partially opened. A gap 29 is created. The catch 1 now engages in a pre-ratchet position as shown in FIG. 10. Engaging in the pre-ratchet position is again achieved with the aid of the pawl 2. The position reached in FIG. 10 can, for instance, be detected by a micro switch or a sensor. Consequently, the drive 6 can be started in such a way that the wheel 10 now turns counterclockwise by around 180. As a result, the position shown in FIG. 11 is reached. The pawl 2 is then pivoted out of the position shown in FIG. 11. This can be achieved by means of an electric drive controlled by sensors to electrically open the latch. The catch 1 can then be pivoted further in the direction of the open position to finally release hood 19, as shown in FIG. 12.

(31) The rocking lever 13 can contain a bent tab 31 as shown in FIG. 2. The tab 31 can rest on a top edge of the plate 15 when the wheel 10 has been turned by approx. 180 from its starting position. This can also ensure a suitable limitation of travel for pivoting the rocking lever 13.

(32) The rocking lever 13 can be stepped, as shown in FIG. 2 in order to reach the wheel 10 and keep the required space to a minimum.

(33) FIGS. 12 and 13 show a locking device whose basic design includes a latch housing 100 on the side of the motor vehicle body and a locking bolt 102 on the side of the hood. This means that the locking bolt 102 is connected to a hood or bonnet 103 only indicted by a dashed line. This means that the invention discloses a hood latch although the invention is naturally not limited to this.

(34) The attachment or arrangement of the latch housing 100 on the motor vehicle body is shown in FIGS. 13 and 14 in such a way that only a top front beam 104 is indicated in the figures as part of the motor vehicle body 104. The front beam 104 contains a recess 105 inside which the latch housing 100 is accommodated.

(35) The latch housing 100 generally contains a frame box 101 as shown and a latch cover connected or connectable to a frame box 101not shown. Whilst the frame box 101 is made of metal and is solid in order to accommodate a locking mechanism 106, 107 mounted therein, the latch covernot shownis typically made of plastic. The locking mechanism 106, 107 comprise a usual catch 106 and pawl 107 that are both pivotally mounted inside the frame box 101 as apparent from the hollow circles indicating the axes of rotation when comparing FIGS. 13 and 14 respectively.

(36) The further basic design includes a closing and opening device 108, 109. In this example embodiment, the closing and opening device 108, 109 is designed as a locking device 108, 109 comprising a rocker arm 108 and a pawl 109 although the invention is not restricted to being a locking device. The Figures also show a motorized drive 110, 111. The motorized drive 110, 111 comprises a driving wheel 111 and an actuating wheel located on the driving wheel 111. The actuating journal 110 does indeed generally extend perpendicular from the driving wheel 111.

(37) The driving wheel 111 in turn is pivoted around an axis 112 in clockwise and counterclockwise direction with the aid of an electric motornot explicitly shown. For this purpose, the driven shaft of the electric motor contains a worm meshing with an external gearing on the outside of the driving wheel 111. During the transition from the functional position of FIG. 13 to the functional position of FIG. 14, the driving wheel 111 carries out a clockwise rotation around its axis 112, taking into consideration a circular arc of around 180, defined by the actuating journal 10.

(38) Of special significance for this embodiment of the invention is the circumstance that the closing and/or opening device 108, 109 or the locking device 108, 109 of the invention engages with the outside of the latch housing 100 in order to adjust the latch housing in relation to the fixed base element 104 as part of a closing/opening operation. As part of this operation, the pawl 109 extends over or behind a projection 113 on the latch housing 100 or a projection 113, which in this case is formed in or on the frame box 101. As a whole, the motorized drive 110, 111 acts eccentrically on the closing and/or opening device 108, 109, as apparent when comparing FIGS. 13 and 14. For this purpose, the actuating journal 110 engages in a slot 114 in the rocker arm 108. The actuating journal 110 actually extends through the respective slot 114 in the rocker arm 108.

(39) The rocker arm 108 is pivotally connected to the base element 104. The same applies to the latch housing 100. In FIGS. 13 and 14 of the embodiment, a design is shown in which the rocker arm 108 and the latch housing 100 are pivotable around the same axis and are connected to the respective basic housing 104. For this purpose, a bolt 115 is provided which is anchored in the base element 104 or the front beam 104, provided at this point. The rocker arm 108 and the latch housing 100 or the frame box 101 are pivotally mounted on this fixed bolt 115. The design may be such that, in the shown view, the rocker arm 108 is arranged below the latch housing 100 and thus also below the frame box 101. This also applies to the pawl 109 which in turn is pivotally mounted on the rocker arm 108. Another bolt 116 is provided for this purpose. In this arrangement, the projection 113 can extend to such a point that the pawl 109 can reach over or behind said projection.

(40) The device functions as follows. FIG. 13 shows the locking device and thus the associated hood 103 in its open position. In order to close the hood 103 it is manually lowered in relation to the motor vehicle body 104 or the front beam 104 to such an extent that the locking bolt 102 mounted on the hood engages as usual in the catch 106 or an infeed section 116 thereof. As a result, the catch 106 is pivoted clockwise around its axis until it finally reaches the main ratchet position shown in FIG. 14. In the main ratchet position the pawl 107 engages in the catch 106, preventing the catch 106 from being pivoted open by the force of a spring, thus releasing the retained locking bolt 102.

(41) In the main ratchet position of the locking mechanism 106, 107, the hood 103 still contains a significant gap S in relation to the motor vehicle body 104 or the front beam 104, as indicated in FIG. 13. This is due to the fact that the closing and/or opening device 108, 109 or the provided pulling-closed device 108, 109 is in its ready position. At the same time, the latch housing 100 is pivoted away from the motor vehicle body 104. The motorized drive 110, 111 also ensures in this position that the hood 103 or the locking bolt 102 cannot flex. This means that the hood 103 or the locking bolt 102 reliably reach the main ratchet position of the locking mechanism 106, 107 as shown in FIG. 14.

(42) The main ratchet position is now in turn detected by a sensor, for instance, a switch. As a result, the motorized drive 110, 111 is acted upon, starting from the ready position as shown in FIG. 13.

(43) As soon as the motorized drive 110, 111 has received the starting signal from the respective sensor or switch on the locking mechanism 106, 107, indicating that the locking mechanism 106, 107 is in the main ratchet position, the electric motor is energized. This results in a clockwise movement of the driving wheel 111 around its axis or axis of rotation 112. The actuating journal 110 extending through the slot 114 in the rocker arm 108, acts accordingly on the rocker arm 108 or locking device 108, 109 in an overall eccentric manner. During this process, the actuating journal 110 carries out an approximately 180 circular movement as apparent from the transition between FIG. 13 and FIG. 14.

(44) At the end of this closing operation as shown in FIG. 14, the actuating journal 110 has moved from a top edge of the slot 114 up to the opposite bottom edge, whilst at the same time pivoting the rocker arm 108 clockwise around its axis or axis of rotation 115. As during the entire process the pawl 109 has retained the latch housing 100 at projection 113 and as the pawl 109 is also pivotally mounted on the rocker arm 108 and is moved along with it, the latch housing 100 also carries out a counterclockwise movement around the common axis 115 together with rocker arm 108 during the transition from FIG. 13 to FIG. 14. The closing operation corresponds to this.

(45) The locking movement of the latch housing 100 or of the rocker arm 108 is carried out against the force of a spring 117. The spring 117 is a spiral spring, whose one end is attached to bolt 115 connected to the motor vehicle body 104, whilst the other free end of the spiral spring 117 pretensions the latch housing 100 and in clockwise direction in relation to the axis or axis of rotation 115.

(46) An end stop or stop buffer 118 on the motor vehicle body 104 provides an end position damping during the described closing process. This is due to the fact that upon reaching the closed position or pulled-closed position shown in FIG. 14, the rocker arm 108 pivoted around axis 115 with the aid of the motorized drive 110, 111 moves against the respective stop or stop buffer 118. The hood 103 is then completely closed in relation to the motor vehicle body 104 corresponding to a minimum gap S as shown in FIG. 14.

(47) FIG. 13 also shows a pyrotechnical element 119 indicated by an arrow. This element ensures that during an accident, the hood 103 can be opened. For this purpose, the pyrotechnical element 119 acts on the pawl in order to pivot it away from the projection 113 on latch housing 100.

(48) The embodiment shown in FIGS. 12 and 13 also preferably contains a closing aid able to move the locking mechanism with its electric drive from a pre-ratchet to a main ratchet position in order to reduce the gap S in a first step. Alternatively or in addition, the latch is designed in such a way that is can be opened with the aid of an electric motor.

LIST OF REFERENCE NUMBERS

(49) 1: Catch 2: Pawl 3: Latch plate 4: Axis for catch 5: Axis for pawl, amongst other things 6: Drive 7: Electric motor 8: Worm 9: Gear system 10: Wheel 11: Bolt of wheel 12: Slot of a rocking lever 13: Rocking lever 14: Plate for a stop 15: Plate 16: Tab 17: Motor vehicle body 18. Locking bolt 19: Hood 20: Stop 21: Axis or shaft of stop 22: Bolt of a plate 23: Tab 24: Shackle of stop 25: Bent tab of rocking lever 26: Bent tab of stop 27: Triggering lever 28. Hook of triggering lever 29: Gap between hood and motor vehicle body 30: Micro switch 31: Bent tab of rocking lever 100: Latch housing 101: Frame box 102: Locking bolt 103: Bonnet 104: Front beam 105: Recess 106 Catch 107: Pawl 108: Rocker arm 109: Pawl 110: Actuating journal 111 Driving wheel 112: Axis 113: Projection 114: Slot 115: Bolt 116: Bolt 117: Spring 118: Stop buffer 119: Pyrotechnical Element S: Gap