Power train mount structure

Abstract

This power train mount structure comprises four mount members (5) that support a power train (1) on a vehicle body, in which: the four mount members (5) each include a cylindrical elastic member (5a); the axial direction of the elastic member (5a) is disposed in parallel to the vehicle width direction; two upper mounts (6) are disposed on the upper side in the vehicle vertical direction; and two lower mounts (7) are disposed on the lower side in the vehicle vertical direction.

Description

Powertrain mounting structure

[0001] The present invention relates to a powertrain mounting structure.

[0002] In the patent document 1 listed below, an electric powertrain is supported on a vehicle body by four mount members, each of which has a cylindrical elastic member, and the axis of each elastic member is arranged parallel to the longitudinal direction of the vehicle. Two front mount members are arranged on the front side of the electric powertrain, and two rear mount members are arranged on the rear side of the vehicle. The front mount members are connected to the front cross member, and the rear mount members are connected to the rear cross member. The mount members generally have an inner tube inserted into the inner hole of the cylindrical elastic member, and the elastic member is inserted into the inner hole of the outer tube.

[0003] International Publication No. 2014 / 097514

[0004] However, in the above powertrain mount structure, the front and rear mount members are offset in the vehicle vertical direction from the center of gravity of the electric powertrain (position of the rotary shaft of the electric motor), and the axes of these mount members are set parallel to the front-to-rear direction of the vehicle, so the couple of vertical road input and powertrain drive reaction force act obliquely on the elastic members of each mount member, causing distortion of the elastic members and reducing their durability.An object of the present invention is to provide a powertrain mount structure in which distortion of the elastic members of the mount members is less likely to occur.

[0005] One aspect of the present invention is characterized in that there are four mounting members that support the powertrain on the vehicle body, the four mounting members having cylindrical elastic members, the axial direction of the elastic members being arranged parallel to the vehicle width direction, and two upper mounts being arranged on the upper side and two lower mounts on the lower side in the vehicle vertical direction.

[0006] According to one aspect of the present invention, the axes of the four mount members are set parallel to the vehicle width direction, so that even if the upper mount and the lower mount are positioned offset in the vehicle fore-and-aft direction relative to the center of gravity of the powertrain, twisting of the elastic member is unlikely to occur. The objects and advantages of the present invention are realized and attained by using the elements and combinations thereof set forth in the appended claims. It should be understood that both the foregoing general description and the following detailed description are merely exemplary and explanatory and are not intended to limit the invention as defined by the claims.

[0007] 1 is a front view showing one embodiment of a powertrain mounting structure; FIG. 2 is a side view of the powertrain mounting structure of FIG. 1; FIG. 3 is an exploded view of the powertrain mounting structure of FIG. 1; FIG. 4 is an explanatory view of an attachment structure of an upper cross member in the powertrain mounting structure of FIG. 1;

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings are schematic and may differ from the actual embodiment. The powertrain mount structure of the embodiment shown in FIGS. 1 and 2 is applied to an electric vehicle using an electric motor 2 as a drive source, and in this example, is applied to the front of the vehicle. FIG. 1 is a front view of the powertrain mount structure, including a partial cross section. FIG. 2 is a side view (left side view of the vehicle) of the powertrain mount structure, but is a left side view of the vehicle as seen from the center in the vehicle width direction. To facilitate understanding of the powertrain mount structure of the embodiment, the main structure will be briefly described using the exploded view of FIG. 3. Note that the powertrain 1 is a general term for a device that transmits the driving force of a drive source, in this case, an electric motor 2, as propulsion force.

[0009] A pair of left and right side members 8 extending in the vehicle's longitudinal direction are disposed on both sides of the vehicle's width (the left side member is not shown in Figure 3 ). Side members 8 generally extend downward in the vehicle's longitudinal center, but since Figure 3 shows the front of the vehicle, they extend in the longitudinal direction at a position slightly higher than the longitudinal center. Strut housings 9 protrude from each side member 8 toward the top of the vehicle at approximately the position of the front wheels. Since these strut housings 9 are located at the front wheel positions of each side member 8, there are a pair of strut housings 9 on each side of the vehicle, similar to the side members 8. A plate-shaped upper cross member 10 is connected to each strut housing 9, connecting the pair of strut housings 9; details of this will be described later.

[0010] A suspension member 11 is connected below the pair of side members 8 and is installed between the pair of side members 8. The suspension member 11 is a rigid member that constitutes a part of the vehicle body (chassis) and connects suspension arms and links that support the front wheels. The suspension member 11 has a lattice structure including a pair of left and right side cross portions 12 extending in the longitudinal direction of the vehicle below the side members 8, a rear cross portion 13 connecting the rear ends of the pair of side cross portions 12, and a front cross portion 14 connecting the front ends of the pair of side cross portions 12. The suspension member 11 has a link portion 15 that extends upward from the connection between the side cross portions 12 and the rear cross portion 13, and the upper end of the link portion 15 is connected to the lower surface of the side member 8. A connecting portion 31 also projects upward from the connection between the side cross portion 12 and the front cross portion 14, and the upper end of the connecting portion 31 is connected to the lower surface of the side member 8. In this suspension member 11, both ends of the rear cross portion 13 in the vehicle width direction, i.e., the vicinity of the connection portion with the side cross portion 12, are made wider in the vehicle longitudinal direction to form wide portions 16.

[0011] The powertrain 1 shown in Figure 3 is configured with an electric motor 2 occupying the upper left portion of the figure, a differential gear 3 located below the electric motor 2, and a reduction gear 4 that mechanically couples the electric motor 2 and the differential gear 3 in the vertical direction of the vehicle. While each component of the powertrain 1 is depicted as a rectangular parallelepiped in Figure 3, in reality, this is not the case. In this example, the electric motor 2 and the differential gear 3 are housed in a single case. The axis of the rotating shaft of the electric motor 2 is set parallel to the vehicle width direction, and the output of this rotating shaft is reduced in speed by the reduction gear 4 and transmitted to the differential gear 3. The differential gear 3 allows for a difference in rotational speed between the driven front left and right wheels, so front left and right drive shafts protrude from the differential gear 3, but these are not shown in Figure 3.

[0012] In this embodiment, four mount members 5 are used to mount the powertrain 1 shown in FIG. 3 to the vehicle body. The four mount members 5 vary in overall shape and size, but each includes a cylindrical elastic member 5a, an inner cylinder 5b inserted into the inner bore of the elastic member 5a, and an outer cylinder 5c into which the elastic member 5a is inserted. The elastic member 5a is typically made of rubber. The outer cylinder 5c is provided with a coupling structure for coupling the elastic member 5a to one of the mounting objects. The coupling structure typically includes a base 32 that supports the outer cylinder 5c and is joined to one of the mounting objects. The base 32 is provided with bolt holes (not shown) through which bolts are inserted. This coupling structure is used to couple the elastic member 5a to one of the two mounting objects, typically the vehicle body, between which it is mounted. A rod member 33, typically made of metal, is inserted into the inner cylinder 5b, and the rod member 33 is supported by the other mounting object, typically the powertrain 1. A bolt may be inserted instead of the rod member 33, and the threaded portion of the bolt may be screwed into the other object to be attached. The specifications of the elastic members 5a may be the same or different. In this embodiment, the four mount members 5 are all set so that the axis of the cylindrical elastic member 5a is parallel to the vehicle width direction.

[0013] Two of the four mount members 5 are attached to the side members 8 and strut housings 9 at their connecting portions so as to span them from the inside in the vehicle width direction, thereby constituting upper mounts 6 of the powertrain 1. The remaining two mount members 5 are attached to the upper surface of the wide portion 16 of the rear cross portion 13 of the suspension member 11 at the connecting portion between the rear cross portion 13, side cross portion 12, and link portion 15, thereby constituting lower mounts 7 of the powertrain 1. Meanwhile, a rod member 33 inserted into the inner hole of the inner cylinder 5b is attached to the powertrain 1 via mounting fixtures 34, and the rod member 33 is fixed integrally to the mounting fixtures 34. The mounting fixtures 34 are attached to four locations: the upper and lower portions of the reduction gear 4, the upper portion of the electric motor 2, and the lower portion of the differential device 3, so that the axial direction of the rod member 33 is parallel to the vehicle width direction. The rod member 33 in this embodiment shown in the figures is a round rod member with a circular cross section, but the cross-sectional shape of the inner hole of the inner tube 5b can be various, such as an oval, an elongated hexagon, a diamond, a rectangle, or one with a groove, and the cross-sectional shape of the rod member 33 may also be various other shapes that suit these shapes.

[0014] By inserting the rod members 33 of each mounting fixture 34 into the inner bore of the inner cylinder 5b of the mount member 5, the powertrain 1 is arranged as two upper mounts 6 on the upper side and two lower mounts 7 on the lower side in the vehicle vertical direction, as shown in FIGS. 1 and 2 . The cylindrical elastic members 5a of all mount members 5 are arranged so that their axes are parallel to the vehicle width direction. Specifically, the upper mounts 6 are arranged above the center of gravity G of the powertrain 1, and the lower mounts 7 are arranged below the center of gravity G of the powertrain 1. The drive shaft of the powertrain 1, not shown, protrudes in a direction generally perpendicular to the paper surface, slightly below the center of gravity G shown in FIG. 2 . The road surface input described above acts, for example, to push the center of gravity G of the powertrain 1 upward toward the vehicle. The drive reaction force acts in a clockwise or counterclockwise direction around the principal axis of inertia of the powertrain 1 in FIG. 2 . These forces or their resultant forces (couple forces) act on any of the mount members 5 in a direction perpendicular to the axis or in a direction around the axis, even if the two upper mounts 6 and the two lower mounts 7 are positioned in a position offset from the center of gravity of the powertrain 1 in the vehicle longitudinal direction, so that the elastic members 5a are unlikely to be twisted. Therefore, the durability of the elastic members 5a can be ensured.

[0015] Furthermore, if the mount members are located on the front and rear sides of the powertrain 1 as in Patent Document 1, the space required in the longitudinal direction of the vehicle from the front mount member through the powertrain 1 to the rear mount member becomes large, which results in a relatively small collapse stroke of the vehicle body at the front of the vehicle. In contrast, in this embodiment, the powertrain 1, the upper mount 6, and the lower mount 7 overlap in a side view of the vehicle, so the space required in the longitudinal direction of the vehicle can be reduced, and as a result, the collapse stroke of the vehicle body at the front of the vehicle can be ensured.

[0016] In this embodiment, the powertrain 1 is made up of the electric motor 2 provided on the upper side (upper portion) of the vehicle, the differential device 3 provided on the lower side (lower portion) of the vehicle, and the reducer 4 that mechanically couples them vertically on the lateral side of the vehicle. As a result, the powertrain 1 is long in the vertical direction of the vehicle but requires little space in the longitudinal direction of the vehicle. When the powertrain 1 is supported on the vehicle body by upper mounts 6 and lower mounts 7, ensuring a sufficient distance (spacing) between the elastic members 5a of the upper mounts 6 and the elastic members 5a of the lower mounts 7 reduces the driving reaction force applied to the elastic members 5a, thereby reducing (softening) the dynamic rigidity of the elastic members 5a and improving noise and vibration performance. If the powertrain 1 is longitudinal in the vehicle longitudinal direction, unless the vehicle vertical length of the mounting fixtures 34 between the powertrain 1 and the upper mount 6 and the mounting fixtures 34 between the powertrain 1 and the lower mount 7 are not unnecessarily increased, it is impossible to ensure the spacing between the elastic members 5 a of the upper mount 6 and the elastic members 5 a of the lower mount 7, and as a result, sound and vibration performance cannot be improved. On the other hand, if the spacing between the elastic members 5 a of the upper mount 6 and the elastic members 5 a of the lower mount 7 is ensured, the length of the mounting fixtures 34 becomes too long, reducing the mount (mounting) rigidity of the powertrain 1, and again, sound and vibration performance cannot be improved. In this embodiment, by making the powertrain 1 longitudinal in the vehicle vertical direction, it is not necessary to unnecessarily increase the vertical length of the mounting fixtures 34, and yet it is possible to ensure the spacing between the elastic members 5 a of the upper mount 6 and the elastic members 5 a of the lower mount 7, thereby improving sound and vibration performance.

[0017] As shown in FIG. 1 , the electric motor 2, which is the driving source, has a large axial length of the rotary shaft, in this case, a large length in the vehicle width direction, in order to ensure power performance. On the other hand, the differential device 3 can have a small length in the vehicle width direction. In this embodiment, as described above, the electric motor 2 is disposed in the upper part of the powertrain 1 and the differential device 3 is disposed in the lower part, so that the upper part of the powertrain 1 has a large length in the vehicle width direction and the lower part has a small length in the vehicle width direction. Looking at the vehicle body, the distance (spacing) between the pair of side members 8 and strut housings 9 in the vehicle width direction is large, while the suspension members 11, particularly the rear cross section 13, have a small length in the vehicle width direction. The distance between the two upper mounts 6, which are connected to the side members 8 and strut housings 9 and support the upper part of the powertrain 1 on the vehicle body, in the vehicle width direction is large to match the length of the upper part of the powertrain 1 in the vehicle width direction. Furthermore, the distance in the vehicle width direction between the two lower mounts 7, which are coupled to the upper surface of the rear cross portion 13 of the suspension member 11 and support the lower part of the powertrain 1 on the vehicle body, is small to match the length of the lower part of the powertrain 1 in the vehicle width direction. Therefore, the distance in the vehicle width direction from the powertrain 1 to the mount member 5 can be small, and the length in the vehicle width direction of the attachment 34 is also small. If the distance in the vehicle width direction from the powertrain 1 to the mount member 5 is large and, as a result, the length in the vehicle width direction of the attachment 34 is large, the mount (mounting) rigidity of the powertrain 1 decreases and the weight of the attachment 34 also increases. In this embodiment, the distance in the vehicle width direction from the powertrain 1 to the mount member 5 is small, and therefore the length in the vehicle width direction of the attachment 34 is also small, so that the mount (mounting) rigidity of the powertrain 1 can be ensured and weight can be reduced.

[0018] As described above, the mount member 5 on the upper side of the vehicle, which constitutes the upper mount 6, is connected to both the side member 8 and the strut housing 9 at their connecting portions. As described in Patent Document 1, when the front mount member is connected to the front cross member and the rear mount member is connected to the rear cross member, the cross member receives bending force due to road surface input and driving reaction force applied in the vertical direction of the vehicle. Although the cross member is also a rigid member, the bending force acts perpendicular to the elongation direction of the beam, making it difficult to ensure the rigidity of the mounting points of the mount members, which is disadvantageous in reducing noise and vibration. Meanwhile, the side member 8 is a beam extending in the vehicle's longitudinal direction, and the strut housing 9 is a beam extending in the vehicle's vertical direction. When the mount member 5 is connected to both the side member 8 and the strut housing 9 at their connecting portions, the mount member 5 is attached to the inner surfaces of both beams in the vehicle width direction. Therefore, the bending force applied to the upper mount 6, which is composed of this mount member 5, is supported in the in-plane direction of the inner surfaces, thereby increasing the rigidity of the mounting points and improving noise and vibration performance. Furthermore, by attaching the mount member 5 across the side member 8 and the strut housing 9, the rigidity between the side member 8 and the strut housing 9 is also improved. Note that, if the support direction against bending input is set to the in-plane direction of the inner surface and rigidity at the attachment point is to be increased, the mount member 5 can be attached to either the side member 8 or the strut housing 9, and this effect can be obtained. Furthermore, in this embodiment, as shown in FIG. 2 , the link portion 15 of the suspension member 11 is connected to the side member 8 near the upper mount 6. As described above, because the suspension member 11 has a lattice structure, the rear cross portion 13 (including the front cross portion 14), which is perpendicular to the link portion 15 and the side cross portion 12, can withstand input in the perpendicular (also called out-of-plane) direction perpendicular to the inner surface, thereby improving rigidity in the perpendicular direction.

[0019] Furthermore, the mount member 5 on the vehicle lower side constituting the lower mount 7 is attached (coupled) to the connection portion between the rear cross section 13 of the suspension member 11, the side cross sections 12, and the link portions 15, and to the upper surface of the wide portion 16 of the rear cross section 13. As described above, the suspension member 11 has a lattice structure. By coupling the lower mount 7 to all connection portions between the rear cross section 13 and the side cross sections 12, which form the lattice structure, and the link portions 15 that couple the lattice to the side members 8, the rigidity of all attachment points in the vehicle width direction, the vehicle fore-and-aft direction, and the vehicle up-and-down direction can be increased. Furthermore, because the lower mount 7 is coupled to the wide portion 16 of the rear cross section 13, which widens the width of the rear cross section 13 in the vehicle fore-and-aft direction, the attachment point rigidity is improved not only in the vehicle fore-and-aft direction but also in the vehicle width direction because the connection width with the side cross sections 12 is increased. By increasing the attachment point rigidity of the lower mount 7 in this manner, vibration transmitted from the electric motor 2 to the interior via the vehicle body is reduced, improving transmission characteristics and noise and vibration performance.

[0020] Next, the previously mentioned upper cross member 10 will be described. FIG. 4 shows the connection portion between the upper cross member 10 and the strut housing 9 on the left side of the vehicle. As is clear from FIG. 4, the upper cross member 10 is a plate-shaped member formed by bending a metal plate. It is connected to the left and right strut housings 9 slightly above the side members 8, connecting the strut housings 9 (the illustration shows a cutaway portion). The upper cross member 10 has a predetermined width in the longitudinal direction of the vehicle, and, for example, accessories are mounted on its upper surface. In this embodiment, a rectangular cutout 17 is provided in the center of the strut housing 9 end of the upper cross member 10 in the longitudinal direction of the vehicle. The upper mount 6 is positioned within this cutout 17 to connect the upper cross member 10 to the strut housing 9. As a result, the connection portion of the upper cross member 10 to the strut housing 9 is positioned so that it partially overlaps the upper mount 6 in the vertical direction of the vehicle. By locating the joining portion of the upper mount 6 close to the joining portion of the upper cross member 10, which connects the left and right vehicle bodies and forms a beam structure in the left-right direction, it is possible to increase the rigidity of the attachment point in the vehicle width direction, improving transmission characteristics and noise vibration performance. In particular, by arranging the upper mount 6 so that it is housed within the cutout portion 17 provided at the end of the upper cross member 10 in the vehicle width direction, the joining portion of the upper mount 6 is located immediately adjacent to the joining portion of the upper cross member 10, further improving the above-mentioned effects.

[0021] As described above, in this embodiment, there are four mount members 5 that support the powertrain 1 on the vehicle body, and the four mount members 5 have cylindrical elastic members 5a, the axes of which are arranged parallel to the vehicle width direction, and are arranged as two upper mounts 6 on the upper side in the vehicle up-down direction and two lower mounts 7 on the lower side. Therefore, even if the upper mounts 6 and lower mounts 7 are arranged offset in the vehicle fore-and-aft direction with respect to the position of the center of gravity of the powertrain 1, the elastic members 5a are unlikely to become twisted.

[0022] Furthermore, the powertrain 1 is configured longitudinally in the vehicle vertical direction by mechanically connecting the upper electric motor 2 and the lower differential 3 in the vehicle vertical direction via the reduction gear 4. This ensures sufficient spacing between the elastic members 5a of the upper mounts 6 and the lower mounts 7 that support the powertrain 1 on the vehicle body, thereby reducing the dynamic rigidity of the elastic members 5a and improving noise and vibration performance. Furthermore, by making the distance between the two upper mounts 6 larger in the vehicle width direction than the distance between the two lower mounts 7 in the vehicle width direction, the electric motor 2, which has a large vehicle width dimension, can be supported by a pair of left and right side members 8 and strut housings 9, and the differential 3, which has a small vehicle width dimension, can be supported by a suspension member 11, which also has a small vehicle width dimension. As a result, the distance from the powertrain 1 to the mount members 5 in the vehicle width direction is short, and the length of the attachments 34 between the powertrain 1 and the mount members 5 in the vehicle width direction can be reduced, thereby ensuring the mount rigidity of the powertrain 1 and achieving weight reduction.

[0023] Furthermore, by connecting the upper mount 6 to at least one of the side member 8 and the strut housing 9, bending input to the upper mount 6 is supported in the in-plane direction on the inner surfaces of the side member 8 and the strut housing 9 in the vehicle width direction, thereby increasing the rigidity of the attachment point and improving noise and vibration performance. Furthermore, by connecting the upper mount 6 to both the side member 8 and the strut housing 9, the rigidity of the attachment point of the upper mount 6 can be further increased, further improving noise and vibration performance. Furthermore, by attaching the mount member 5 across the side member 8 and the strut housing 9, the rigidity between the side member 8 and the strut housing 9 is also improved.

[0024] Furthermore, by connecting the lower mount 7 to the connecting portion of the rear cross portion 13, side cross portion 12, and link portion 15 of the suspension member 11, the rigidity of all mounting points of the lower mount 7 in the vehicle width direction, vehicle longitudinal direction, and vehicle vertical direction can be increased, reducing vibration transmitted from the electric motor 2 to the interior of the vehicle via the vehicle body, improving transmission characteristics and improving noise and vibration performance. Furthermore, because the lower mount 7 is connected to the wide portion 16 of the rear cross portion 13 that widens the width in the vehicle longitudinal direction, the mounting point rigidity is improved not only in the vehicle longitudinal direction but also in the vehicle width direction because the connecting width with the side cross portion 12 is increased. As a result, transmission characteristics and noise and vibration performance can be further improved.

[0025] Furthermore, by positioning the upper cross member 10 so that the connection portion with the strut housing 9 partially overlaps the upper mount 6 in the vertical direction of the vehicle, the connection portion of the upper mount 6 is brought close to the connection portion of the upper cross member 10, thereby increasing the rigidity of the attachment point of the upper mount 6 in the vehicle width direction, improving transmission characteristics and noise and vibration performance. Furthermore, by providing a cutout 17 at the end of the plate-shaped upper cross member 10 on the strut housing 9 side and positioning the upper mount 6 inside this cutout 17, the connection portion of the upper mount 6 is brought close to the connection portion of the upper cross member 10, further increasing the rigidity of the attachment point of the upper mount 6 in the vehicle width direction, further improving transmission characteristics and noise and vibration performance.

[0026] REFERENCE SIGNS LIST 1...power train, 2...electric motor, 3...differential device, 4...reduction gear, 5...mounting member, 5a...elastic member, 6...upper mount, 7...lower mount, 8...side member, 9...strut housing, 10...upper cross member, 11...suspension member, 12...side cross portion, 13...rear cross portion, 14...front cross portion, 15...link portion, 16...wide portion, 17...notch portion

Claims

1. The powertrain has four mounting members that support it to the vehicle body, and the four mounting members each have a cylindrical elastic member, the axial direction of the elastic member is arranged parallel to the vehicle width direction, and the two upper mounts and two lower mounts are arranged on the upper side and lower side respectively in the vehicle vertical direction. The powertrain mounting structure is characterized by comprising an electric motor provided at the top, a differential gear provided at the bottom, and a reduction gear that mechanically connects the electric motor and the differential gear in the vertical direction of the vehicle.

2. The powertrain mount structure according to claim 1, characterized in that the distance in the vehicle width direction between the two upper mounts is greater than the distance in the vehicle width direction between the two lower mounts.

3. The powertrain mount structure according to claim 1, wherein the vehicle body has a pair of side members that extend in the longitudinal direction of the vehicle and are arranged on both sides in the width direction of the vehicle, and a pair of strut housings that project upward in the vertical direction of the vehicle from each of the pair of side members, and the upper mount is coupled to at least one of the side members and the strut housing.

4. The powertrain mount structure according to claim 3, characterized in that the upper mount is coupled to both the side member and the strut housing.

5. The powertrain mount structure according to claim 1, comprising a suspension member mounted and connected to a pair of side members below a pair of side members, wherein the suspension member has a rear cross portion extending in the vehicle width direction on the rear side in the vehicle longitudinal direction, side cross portions extending in the vehicle longitudinal direction on both sides in the vehicle width direction, and a link portion extending in the vehicle vertical direction at the connection point between the rear cross portion and the side cross portion and connected to the pair of side members, and the lower mount is connected to the connection point of the rear cross portion, the side cross portion and the link portion.

6. The powertrain mount structure according to claim 5, characterized in that the rear cross portion has a wide portion in the vehicle longitudinal direction near the connection point with the side cross portion, and the lower mount is connected to the wide portion.

7. The vehicle body has an upper cross member connected to the strut housing between a pair of strut housings, and the upper cross member is arranged such that the connection portion with the strut housing partially overlaps with the upper mount in the vertical direction of the vehicle, as described in claim 1.

8. The powertrain mount structure according to claim 7, characterized in that the upper cross member is a plate-shaped member having a predetermined width in the vehicle longitudinal direction, has a notch at the end on the strut housing side, and the upper mount is arranged inside the notch.