DE102019203815A1 - Subframe for a motor vehicle - Google Patents

Abstract

The invention relates to a subframe for a motor vehicle, with a unit mounting, in which a drive unit (5) is supported on a bearing bracket (23) of the subframe via at least one unit bearing (7), the unit bearing (7) with a screw bolt (21) is screwed to a screw stud (32) of the bearing bracket (23), and wherein the screw bolt (21) is guided in a screwing direction (S) through a duct (37) of the screw stud (32) and a bolt head (47) of the screw bolt (21 ) is braced against the opening edge region of the mouth opening (39) of the screw boss (32) on the screw head side.

Description

The invention relates to an auxiliary frame for a motor vehicle according to the preamble of claim 1 or 5.

A drive unit, for example an electric machine, can be supported in a manner known per se on such an auxiliary frame. The subframe can be constructed in the form of a frame from subframe longitudinal members and subframe cross members and be connected to the vehicle body.

In the case of a generic subframe, the drive unit is supported on a bearing bracket of the subframe via at least one unit bearing. The assembly bearing is screwed to a screw stud on the bearing bracket with a screw bolt. For this purpose, the screw bolt is guided in a screwing direction through a feed-through channel of the screw stud and is braced with its bolt head against the opening edge area of the screw-head-side opening of the screw stud.

Due to the high package density in the area of the subframe, an installation situation can arise in which the screw head-side opening of the screw boss is spaced apart in an axial extension over an assembly clearance from a subframe interfering contour. In order to enable a structurally simple, disruptive contour-free access of the screw bolt into the screw lug, it is necessary for geometrical circumstances that the assembly clearance is greater than the bolt length of the screw bolt.

From the DE 10 2009 020 107 A1 an arrangement of a unit bearing is known. From the KR 2007 0062 075 a body-side support structure with a bearing bracket is known to which an assembly bearing is attached.

The object of the invention is to provide a subframe for a motor vehicle in which the assembly of the drive unit with the subframe is simplified.

The object is achieved by the features of claim 1 or 5. Preferred developments of the invention are disclosed in the subclaims.

According to the characterizing part of claim 1, the mouth opening of the screw boss on the screw head side is extended axially in the screwing direction with an insertion gap formed on the screw boss peripheral side. As a result, when the assembly bearing is attached to the bearing bracket, the still loose screw bolt can first be inserted in an insertion direction with its bolt tip through the insertion gap into the duct of the screw stud, namely offset via an axial offset to the screw head-side opening of the screw stud. As a result of this axial offset, the assembly clearance between the mouth opening of the screw boss on the screw head side and a subframe interference contour can be dimensioned smaller than the screw bolt length. The still loose screw bolt can also be threaded into the duct of the screw boss in an inclined position to the screwing direction.

In a technical implementation, the insertion gap can extend over at least part of the screw stud or over the entire length of the screw stud. The lead-through channel of the screw stud can have an insertion cross-section that is open radially outward via the insertion gap. The lead-through channel is thus designed with an approximately U-shaped cross-section in the region of the insertion gap.

In contrast to this, the lead-through channel of the screw boss can have a circumferentially closed cross section on the side facing the assembly bearing, which cross section is delimited by means of a circumferential, annular circumferential wall. The insertion gap can extend over a gap length from the mouth opening on the screw head side to an edge of the peripheral wall on the screw head side.

The special screw socket geometry claimed in claim 1 can be used in particular in the specific installation situation described below: In this specific installation situation, the bearing bracket can have a reinforcement strut bridging the inside corner area between a subframe longitudinal member and a subframe cross member. The screw stud, to which the assembly mount can be screwed, can be formed in the reinforcement strut. The reinforcement strut can have a hollow profile with two opposing sheet metal profile walls. For a rigid component connection to the reinforcement strut, the screw socket can be positioned in the hollow profile of the reinforcement strut and inserted into corresponding assembly openings in the opposite profile walls on its end faces. The screw stud can be welded to the opening edge of the respective assembly opening.

It should be emphasized that the above specific installation situation is not only to be considered in combination with the screw socket geometry claimed in claim 1, but also as an aspect of the invention that is independent therefrom and is claimed in the subordinate claim 5. Using the above defined bearing bracket, the assembly bearing can be installed in the subframe in a space-saving manner and protected from external mechanical influences.

With a view to a further simplification of assembly, a radially widened recess can be formed in the opening edge of the assembly opening on the screw head side, which recess is aligned in radial alignment with the screw socket insertion gap. The recess simplifies the access of the screw bolt to the insertion gap of the screw lug duct.

In a specific embodiment variant, the reinforcement strut, the subframe longitudinal member and the subframe cross member can lie approximately in a common horizontal subframe plane. The mouth opening of the screw boss on the screw head side can face the inner corner area (spanned by the subframe longitudinal member and the subframe cross member). According to the invention, the assembly clearance available for inserting the screw bolt (between the mouth opening of the screw socket on the screw head side and an interfering subframe contour) can be dimensioned smaller than the screw bolt length.

In the installation situation sketched above, the still loose screw bolt can be inserted in an insertion direction approximately at right angles to the subframe plane and in an inclined position to the screwing direction with its pin tip through the insertion gap of the screw socket duct and inserted into it.

Then an angle screwdriver can be attached to the screw head of the screw bolt, which is still loosely inserted into the screw socket, in order to screw the screw bolt to the assembly bearing.

The assembly bearing can, for example, be an elastomer bearing with a cylindrical bearing outer sleeve and an inner bearing sleeve with an elastomer body arranged in between. The screw bolt can be guided with its bolt tip through the cylindrical bearing inner sleeve and protrude beyond it to the outside. The bolt tip of the screw bolt can be screwed to a fastening nut so that the assembly mount is firmly clamped between the fastening nut and the screw bolt.

An exemplary embodiment of the invention is described below with reference to the accompanying figures.

• 1 in einer Ansicht von oben einen Hilfsrahmen für ein Kraftfahrzeug mit darauf abgestützter Elektromaschine;
• 2 in perspektivischer Darstellung Hilfsrahmen mit weggelassener Elektromaschine;
• 3 eine vergrößerte Schnittdarstellung entlang einer xy-Schnittebene;
• 4 eine Detail-Schnittansicht der Lagerkonsole; und
• 5 bis 9 jeweils Ansichten, anhand derer ein Montagevorgang zur Befestigung des Aggregatelagers an der hilfsrahmenseitigen Lagerkonsole veranschaulicht ist.

Show it:

• 1 in a view from above an auxiliary frame for a motor vehicle with an electric machine supported thereon;
• 2 a perspective view of the auxiliary frame with the electric machine omitted;
• 3 an enlarged sectional view along an xy sectional plane;
• 4th a detailed sectional view of the bearing bracket; and
• 5 to 9 in each case views, based on which an assembly process for fastening the assembly bearing to the subframe-side bearing bracket is illustrated.

In the 1 a subframe for a motor vehicle is shown in a view from above. The subframe has subframe side members 1 and subframe cross members 3 on. The subframe is an electric machine as the drive unit 5 Supported in a three-point bearing, via assembly bearings 7th , 9 , 11 . Each of the aggregate bearings 7th , 9 , 11 is in the 1 realized as an elastomer bearing. Its structure is roughly schematically shown in 3 or 4th indicated. Accordingly, the elastomer bearing consists of an outer bearing sleeve 13 , a bearing inner sleeve 15th as well as an elastomer body arranged in between 17th built up. The aggregate bearings 7th , 9 , 11 are with their bearing outer sleeve 13 each in fastening eyes 19th (in the 1 or 3 indicated) of the electric machine 5 pressed in. In addition, the aggregate bearings are 7th , 9 , 11 about bolts 21st with storage consoles 23 of the subframe screwed.

The invention relates to in the 1 Connection of the assembly bearing shown below on the left 7th on the subframe-side bearing bracket 23 . Accordingly, the bearing bracket points 23 a reinforcement strut 25th on that has an inside corner area 27 between the subframe side member 1 and the subframe cross member 3 bridged. The reinforcement strut 25th is as a hollow profile part with two opposing profile walls 29 , 31 educated. Another component is the bearing bracket 23 next to the reinforcement strut 25th a screw socket 32 on that in the hollow profile 30th ( 4th ) of the reinforcement strut 25th is arranged. The screw slug 32 towers over with its front sides 61 ( 4th ) mounting openings 33 , 35 the opposite profile walls 29 , 31 the reinforcement strut 25th . For a rigid connection of the screw socket 32 is this with the opening edge area of the respective mounting opening 33 , 35 the profile walls 29 , 31 in welded connection 36 ( 3 or 7th ).

The reinforcement strut 25th lies together with the subframe side member 1 and the subframe cross member 3 roughly in a common horizontal subframe plane H ( 5 ).

As from the 3 or 4th shows is the screw slug 32 approximately hollow-cylindrical, with a radially inner duct 37 , the Indian 4th a screw head-side mouth opening at the front 39 and an orifice on the assembly side 41 having.

In the 3 shows an assembled state in which the assembly mount 7th with the storage console 23 is screwed. As a result, the bolt is 21st in the screwing direction (or along the screwing axis) S through the duct 37 as well as through the inner bearing sleeve 15th of the aggregate bearing 7th guided, with the bolt tip 43 the aggregate bearing 7th surmounted by a protrusion. The tip of the bolt 43 is in threaded engagement with a mounting nut 45 , between the and the bolt head 47 the inner bearing sleeve 15th and the screw boss 32 are axially braced together.

As from the 1 or 8th emerges is the mouth opening on the screw head side 39 of the screw neck 32 in axial extension over an assembly clearance f from an axially opposite subframe interfering contour 49 (i.e. an inside of the subframe side member 1 ) spaced. The assembly clearance f is dimensioned according to the invention much smaller than the screw bolt length a ( 3 ) of the screw bolt 21st .

In order to ensure an introduction of the screw bolt without interference contours 21st in the screw socket 32 The opening on the screw head side is to be made possible 39 with an insertion gap 51 axially in the screwing direction S. extended. The insertion gap 51 is on the circumferential side of the screw 53 ( 4th ) educated. In the area of the insertion gap 51 is the cross-section of the screw socket duct 37 designed to be radially open to the outside. The insertion gap 51 extends in the 4th or 7th over a gap length b from the mouth opening on the screw head side 39 up to an edge on the screw head side 55 a screw lug peripheral wall 57 . The circumferential, annular peripheral wall 57 of the screw neck 32 is at his, the aggregate store 7th Formed facing side and delimits a circumferentially closed cross section of the screw-through channel 37 .

As can be seen from the figures, the free insertion cross-section is in the screw socket 32 in the vertical direction of the vehicle z designed to be open at the top. To further simplify assembly, the assembly opening on the screw head side is in the edge of the opening 33 the profile wall 29 a radially expanded recess 69 ( 4th to 7th ) educated. This is in radial alignment with the insertion gap 51 aligned and allows access to the still loose screw bolt 21st to the duct 57 of the screw neck 32 ( 7th ).

The following is based on the 5 to 9 the assembly of the assembly bearing 7th with the storage console 23 described. As a result, the bolt is still loose 21st with reference to the screwing direction S. with its bolt tip 43 at a skew angle a ( 6th or 7th ) through the profile wall recess 69 as well as through the insertion gap 51 into the screw socket duct 37 inserted, in a direction of insertion z (that is, to the bottom of the vehicle). In the 7th comes the tip of the bolt 43 of the bolt 21st by an offset c to the mouth opening on the screw head side 39 offset in contact with a channel bottom of the duct 37 .

Then the screw bolt 21st loosely in the duct 37 inserted, in alignment with the screwing direction S. ( 8th ) and with its bolt head 47 up to contact with the end wall on the screw head side 61 of the screw neck 32 pushed ( 9 ), with a washer in between 63 . In a subsequent process step, an angle wrench is attached to the bolt head 47 of the bolt 21st attached and the bolt 21st with the fastening nut 45 screwed.

List of reference symbols

1

Subframe side members

3

Subframe cross member

5

Electric machine

7, 9, 11

Aggregate bearings

13

Bearing outer sleeve

15th

Bearing inner sleeve

17th

Elastomer body

19th

Fastening eye

21st

Bolt

23

Storage console

25th

Reinforcement strut

27

Inside corner area

29, 31

Profile walls

30th

Hollow profile

32

Screw lugs

33, 35

Assembly opening

36

Welded joint

37

Implementation channel

39.41

Mouth openings

43

Bolt tip

45

Fastening nut

47

Bolt head

49

Interfering contour

51

Insertion gap

53

Screw lug circumferential side

55

edge

57

Perimeter wall

61

Screw lug front side

63

Washer

69

Recess

a

Bolt length

b

axial gap length

c

Axial misalignment

f

Assembly clearance

S.

Screw direction

z

Direction of insertion

H

Subframe level

α

Skew angle

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102009020107 A1 [0005]
• KR 20070062075 [0005]

Claims (9)

Auxiliary frame for a motor vehicle, with a unit mounting, in which a drive unit (5) is supported via at least one unit bearing (7) on a bearing bracket (23) of the subframe, the unit bearing (7) being attached to a screw stud (21) with a screw bolt (21). 32) of the bearing bracket (23) is screwed, and wherein the screw bolt (21) is guided in a screwing direction (S) through a duct (37) of the screw boss (32) and a bolt head (47) of the screw bolt (21) against the opening edge area the screw head-side mouth opening (39) of the screw boss (32) is clamped, characterized in that, to simplify assembly, the screw head-side mouth opening (39) is extended axially in the screwing direction (S) with an insertion gap (51) formed in the screw socket peripheral side (53) . Subframe after Claim 1 , characterized in that for the attachment of the assembly bearing (7) to the bearing bracket (23) the still loose screw bolt (21) with its bolt tip (43) by an axial offset (c) to the screw head-side opening (39) through the insertion gap (51) can be inserted into the feed-through channel (37) of the screw boss (32), specifically in an insertion direction (z). Subframe after Claim 1 or 2 , characterized in that the insertion gap (51) extends over at least part of the screw socket (32) or over the entire length of the screw socket, and / or that the lead-through channel (37) of the screw socket (32) extends over the insertion gap (51) having radially outwardly open insertion cross-section. Subframe after Claim 1 2 or 3, characterized in that the duct (37) of the screw boss (32) has a circumferentially closed cross-section on its side facing the assembly bearing (7), with a circumferential, annular circumferential wall (57), and in particular the insertion gap (51) extends over a gap length (b) from the mouth opening (39) on the screw head side to an edge (55) on the screw head side of the peripheral wall (57). Auxiliary frame for a motor vehicle, with a unit mounting, in which a drive unit (5) is supported via at least one unit bearing (7) on a bearing bracket (23) of the subframe, the unit bearing (7) being attached to a screw stud (21) with a screw bolt (21). 32) of the bearing bracket (23) is screwed, and wherein the screw bolt (21) is guided in a screwing direction (S) through a duct (37) of the screw boss (32) and a bolt head (47) of the screw bolt (21) against the opening edge area the mouth opening (39) of the screw boss (32) on the screw head side is clamped, characterized in that the bearing bracket (23) has a reinforcing strut (25) bridging the inner corner area (27) between an auxiliary frame longitudinal member (1) and a subframe cross member (3), in which the screw stud (32) is formed, and that in particular the screw head-side mouth opening (39) of the screw stud (32) faces the inner corner area (27) t. Subframe after Claim 5 , characterized in that the reinforcement strut (25) is a hollow profile part with two opposing profile walls (29, 31), and that the screw socket (32) is arranged in the hollow profile (30) of the reinforcement strut (25), and / or that the screw socket ( 32) is inserted at its end faces (61) into assembly openings (33, 35) of the opposing profile walls (29, 31), and / or that the screw socket (32) is welded to the opening edge of the respective assembly opening (33, 35) (36 ) is. Subframe after Claim 6 , characterized in that a radially widened recess (69) is formed in the opening edge of the screw head-side assembly opening (39), which is aligned in radial alignment with the insertion gap (51), and that the recess (69) provides access to the screw bolt (21) Introducing gap (51) of the duct (37) provides. Subframe according to one of the preceding claims, characterized in that the reinforcement strut (25) of the subframe longitudinal member (1) and the subframe cross member (3) lie approximately in a common, in particular horizontal subframe plane (H), and / or that the screw head-side opening (39 ) of the screw stud (32) is axially extended over an assembly clearance (f) from an interfering contour (49) of the subframe, and that in particular the screw bolt (21) has a bolt length (a) which is greater than the assembly clearance (f) is. Subframe after Claim 8 , characterized in that the insertion direction (z) of the screw bolt (21) is oriented approximately at right angles to the substantially horizontal subframe plane (H).

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