JPH11166570A - Manufacture of vehicle body member with dynamic damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of building a dynamic damper in closed space formed by welding a vehicle body member. SOLUTION: A vehicle body member of hollow beam shape having closed space 12 inside is composed of a body part 10 partially opened, and a closing plate 11 covering this opened part. A mass body 20 is accommodated in the space of the body part 10 before closing it with the closing plate 11, and a bolt 21 is protruded outward from a damper elastic body fitting hole 14 formed in the body part 10, and temporarily fastened to the body part by a nut 26 so as to be conductive. The closing plate 11 is then welded to the body part 10 to form closed space 12. A current is then applied to the body part 10 to perform cation electrostatic coating. After temporary fastening is unfastened, an insulator is fitted to the damper elastic body fitting hole 14, and the bolt 21 is refitted thereto by the nut so as to compose a built-in dynamic damper of a mass body 20 and a damper elastic body constituting the insulator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow body member, such as a subframe, interposed between a vibration source side and a vibration receiving side such as a subframe interposed between an engine of a vehicle and a vehicle body. The present invention relates to a device equipped with a damper and a manufacturing method thereof.

[0002]

2. Description of the Related Art A vehicle body member for a vehicle, for example, a subframe, is a hollow member for supporting an engine and having both ends in the longitudinal direction attached to the vehicle body. Vibration occurs with the part as the fixed end. Therefore, in order to suppress this vibration, it is common practice to interpose a vibration isolator between the mounting portions at both ends and the vehicle body, and to provide a dynamic damper as a vibration damper at an appropriate place.

An example of a vehicle member provided with such a dynamic damper is Japanese Utility Model Laid-Open No. 3-75338.
In this example, a jacking-up closing plate is bolted to the open side of a body member having a substantially U-shaped open cross section, and a dynamic damper is accommodated in a space formed between the body member and the closing plate. A structure is shown in which a bolt provided on the dynamic damper is projected outward from a vehicle body member and fixed with a nut. If the dynamic damper is accommodated in the hollow portion of the vehicle body member in this way, it becomes easier to dispose the dynamic damper while avoiding interference with other components mounted on the vehicle body member or the like.

[0004]

SUMMARY OF THE INVENTION
As in No. 38, the vehicle body member is required to have high rigidity and light weight. For this purpose, it is preferable that the closing plate is not detachable by bolting, but is welded to have a closed cross-sectional structure.

However, if the closing plate is welded to form a closed section, the dynamic damper cannot be accommodated in the closed space thereafter. Therefore, the dynamic damper must be attached to the main body or the like before welding.
In this case, since the damper elastic body deteriorates in the subsequent coating process, it was virtually impossible to incorporate the dynamic damper in the closed space formed by such welding. The present invention makes this possible.

[0006]

According to a first aspect of the present invention, a method of manufacturing a vehicle body member having a dynamic damper according to the present invention includes a body having an open cross section and a closing plate which covers an open portion of the body. In a method of manufacturing a body member in which a closed space is formed and a dynamic damper is accommodated in the closed space and both ends in the length direction are attached to the vehicle body, the closing plate is welded to the main body. A temporary fixing step of supporting the mass body on the previous closing plate or the main body without interposing the damper elastic body, and thereafter, the opening of the main body is covered with the closing plate, and the main body and the closing plate are welded and closed. A welding process for forming a space, a painting process for painting the main body and the closing plate after the welding process, After mounting a damper elastic body after removing the temporary fixing member to the body portion or the closing plate, it is characterized in that a final supporting step to float support the mass body through the damper elastic bodies.

According to a second aspect of the present invention, in the temporary fixing step of the first aspect, the mass body is temporarily fixed by using a damper elastic body mounting hole provided in advance in the main body or the closing plate. And

According to a third aspect of the present invention, in the temporary fixing step of the first aspect, the mass body and the main body portion or the closing plate supporting the mass body are conductively mounted, and the main body portion and the closing plate are connected in a subsequent welding process. And the mass body is electrostatically coated at the same time.

A fourth invention is characterized in that, in the third invention, a portion which is not painted by the temporary fixing is plated in advance.

[0010]

According to the first aspect of the invention, before welding the closing plate to the main body, the mass of the dynamic damper is temporarily fixed to the main body or the closing plate without interposing the damper elastic body. Since the coating is performed, there is no possibility that the damper elastic body is deteriorated in the coating process.

After that, the temporary fixing is removed, and the damper elastic body is attached to the main body or the closing plate, and the mass body is floated and supported via the damper elastic body, so that at least the mass body is accommodated in the closed space of the vehicle body member. The dynamic damper in the state can be provided, and as a result, the dynamic damper can be built in even if the hollow portion of the vehicle body member forms a closed space.

According to the second invention, in the temporary fixing step of the first invention, the damper elastic body is not attached to the damper elastic body mounting hole provided in advance in the main body or the closing plate. By using the holes, temporary fixing such as, for example, projecting a bolt extending from the mass body side to the outside and fixing with a nut can be easily performed. In addition, since a damper elastic body is finally attached to this mounting hole, it is not necessary to form a special hole for temporary fixing, and one mounting hole can be used effectively.

According to the third aspect of the present invention, since the mass body is built in and the conductive coating is temporarily fixed to the main body without interposing the damper elastic body, the main body is connected to the electrode and electrostatic painting is performed. The mass can be painted together. Therefore, the number of painting steps can be reduced, and the overall durability can be improved by painting the built-in mass body.

In addition, since the mass body is temporarily fixed to the main body so as to be able to conduct without passing through the damper elastic body, the mass body is connected to the electrode and electrostatic painting is performed, so that the body member and the mass body can be painted together. Therefore, the number of painting steps can be reduced, and the overall durability can be improved by painting the built-in mass body.

According to the fourth aspect of the present invention, in the coating step of coating in a temporarily fixed state, a portion where the temporary fixing member abuts is left unpainted as a portion which is not coated by the temporary fixing. However, by pre-plating a part that is not painted by such temporary fixing, it is protected from rust and the like, like other painted parts. In addition, continuity with respect to the mass body during electrostatic coating can be favorably maintained by plating.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to the drawings. FIG. 1 is a partial sectional view of a vehicle body member according to the present embodiment, FIG. 2 is a schematic view showing an example of use of the vehicle body member, and FIG. 3 is a sectional view taken along line 3-3 in FIG.

As shown in FIG. 2, both ends of the vehicle body member 1 are attached to the vehicle body 4 via insulators 3 (see FIGS. 1 and 4 to 6) by mounting members 2 and the engine 5 and transmission 6 is a member that supports components serving as vibration sources, such as the power unit 6 and the differential 7.

FIG. 2 is an example, and there are various other members to which the present invention is applied as a vehicle body member for supporting a component serving as a vibration source. For example, there is a support member for a suspension component. In addition to the above-described one in which both ends in the length direction are attached to the vehicle body, a cantilever type in which one end is attached to the vehicle body and the other end is attached to the vibration source side may be used.

Further, in the present invention, the insulator is a vibration isolator comprising two mounting portions mounted on the vibration source side and the vibration receiving side and a damper elastic body such as rubber for connecting the two mounting portions. It contains a flexible cylindrical rubber vibration isolator.

FIG. 1 is a view showing one vehicle body member 1 in a cross section in the length direction, and omitting a substantially half of the left side of the figure from a center line C indicating the middle in the length direction. As is clear from FIG. 3 and FIG. 3, the vehicle body member 1 is provided with a dynamic damper 8 in which most of the dynamic damper 8 is built.

The vehicle body member 1 is a relatively long and hollow vehicle body member having a closed space 12 formed by a main body 10 made of sheet metal and a closing plate 11, and both ends in the longitudinal direction are crushed. And mounting members 3 are provided near both ends.

As shown in FIG. 3, the main body 10 is a member having a substantially U-shaped cross section with a downward cross section, and having flanges 13 on both sides. The closing plate 11 forms a closed space 12 by welding both sides in the width direction with the flange 13.

In the present application, the longitudinal direction of the main body 10, the closing plate 11, and the vehicle body member 1 is referred to as vertical, and the direction perpendicular thereto is referred to as horizontal.

A pair of damper elastic mounting holes 14 are formed at symmetrical positions with respect to the center line C of the main body 10, and a collar 15 is fitted into each of the damper elastic mounting holes 14 and welded. An insulator 16 is press-fitted into the collar 15. The insulator 16 is composed of an outer cylinder 17 and an inner cylinder 18 arranged concentrically and a damper elastic body 19 such as rubber for connecting these.

A bolt 21 protruding from the mass body 20 housed and arranged in the closed space 12 penetrates from the inside to the outside of the inner cylinder 18, and a nut 22 is fastened to the protruding end thereof. The mass body 20 is a single member that extends long to the left and right across the center line C. Bolts 21 and washers 27 through which the bolts 21 penetrate are provided at both left and right ends, and each washer 27 is welded onto the mass body 20 in advance. Have been.

The bolt 2 of the closing plate 11
An opening 28 is also formed in the vicinity of 1 to also serve as a hollow or air vent. The sizes of the opening 28 and the damper elastic body mounting hole 14 are smaller than the mass 20, respectively, so that the mass 20 cannot enter and exit through these openings.

These mass body 20, bolt 21, inner cylinder 1
8 and the total mass M of the nut 22 and the insulator 16
The dynamic damper 8 having a predetermined vibration damping performance is formed by the correlation with the spring constant K of the damper elastic body 19.

The dynamic damper 8 is floatingly supported by the vehicle body member 1 at a substantially middle portion in the longitudinal direction of the vehicle body member 1, and most of the dynamic damper 8 including the mass body 20 is It is built into the closed space 12.

The dynamic damper 8 is arbitrarily set so as to cancel the natural resonance frequency of the fixed end vibration of the vehicle body member 1. Based on the setting, the total mass M and the spring constant K of the damper elastic body 19 are determined. Is done.

Therefore, the mass of the mass body 20 is
Although it is determined in relation to other members such as 1, the size is considerably large, so that it is impossible to put in and out of the closed space 12 through the damper elastic body mounting hole 14 or the collar 15.

Next, a method of manufacturing the vehicle body member will be described. 4 and 5 show a temporary fixing step. FIG. 4 shows a state before the closing plate 11 is attached.
First, the mass body 20 is put into the recessed space of the main body 10, and the bolt 21 is made to penetrate into the collar 15 and is taken out.

When the bolt 21 is fastened to the tip of the bolt 21 with a nut 26 via a washer 25 and the mass body 20 is temporarily fixed to the main body 10, the state shown in FIG. 5 is obtained. At this time, the insulator 16 has not been attached to the collar 15 yet, and
And the mass body 20 include a washer 25, a nut 26, and a bolt 2
1 can be conducted.

The washer 25 and the nut 26 are temporary fixing members.
The one end surface and the other end surface of the collar 15 with which the abutment is in contact, and the surface portion of the washer 27 integral with the mass body 20 with which the other end surface abuts are unpainted portions, and these unpainted portions are plated in advance. ing.

Subsequently, a welding step is performed. As shown in FIG. 5, with the mass body 20 temporarily fixed, the closing plate 11 is fitted to the main body 10, the both sides in the width direction of the cover 11 and the flange 13 are overlapped and welded, and the main body 10 is opened. Then, the vehicle body member 1 is assembled. Thereby, a closed space 12 is formed.

In the subsequent painting step, the vehicle body member 1 is suspended from the electrodes, and the vehicle body member 1 and the mass body 20 communicating therewith are energized to perform known cationic electrostatic coating. , The inner and outer surfaces of the vehicle body member 1 and the respective surfaces of the mass body 20 and the bolts 21 are simultaneously attracted to each other, and they are painted together in a subsequent baking process.

At this time, since the insulator 16 is not attached, the insulator 16 is formed by electrostatic painting.
There is no possibility that the damper elastic body 19 of the above will be deteriorated. Moreover,
The mass body 20 is connected to the main body 10 and the closing plate 11.
Since the coating can be performed at the same time, the number of coating steps can be reduced, and the overall durability can be improved by coating the built-in mass body.

After the coating step, the nut 26 and the washer 25 are removed, and the insulator 1 is removed as shown in FIG.
6 is press-fitted into the collar 15, and a final support step of fastening the tip of the bolt 21 projecting from the inner cylinder 18 of the insulator 16 again with the nut 22 via the washer 23 is performed.

As a result, the mass body 20 is housed in the closed space of the vehicle body member 1 and is floatingly supported by the body 16 of the vehicle body member 1 via the insulator 16 as shown in FIG.
And the state of FIG.

At the same time, the mass body 20, the bolt 21, the inner cylinder 1
8 and a nut 22 as mass parts, and a damper elastic body 19 of the insulator 16 as an elastic part.
Are easily formed.

Thus, before closing the closing plate 11, the mass body 2 which is a part of the dynamic damper 8 is closed.
0 is accommodated in the main body 10 and then the closing plate 11 is closed, so that even if the hollow portion of the vehicle body member 1 forms a closed space 12 by welding, most of the dynamic damper 8 including the mass body 20 can be incorporated.

Further, in the coating step, the washer 25, which is a temporary fixing member, is fixed to the collar 15 by the nut 26.
Abuts against one end surface of the mass body 20 and the other end surface
Portions that are not painted due to temporary fixing caused by contacting the upper washer 27 are plated in advance.

Therefore, the parts that are not painted by these temporary fixings remain unpainted when the temporary fixing state is released after the painting process, but since they have been plated in advance, they are protected from rust and the like like the other painted parts. You. In addition, since these portions, especially both contact portions of the collar 15 and the washer 27, are not coated with an insulating coating but are plated, it is possible to maintain good conduction with the mass body 20 during electrostatic coating.

In addition, since the bolt 21 extending from the mass body 20 is protruded to the outside using the damper elastic body mounting hole 14 and temporarily fixed by the nut 22, the temporary fixing can be easily performed. it can. Moreover, since the insulator 16 is finally attached to the damper elastic body mounting hole 14, there is no need to form a special hole for temporary fixing, and one damper elastic body mounting hole 14 can be used effectively.

In the vehicle body member 1 thus configured, the main body 10 and the closing plate 11 are integrated by welding, so that higher rigidity and lighter weight can be realized as compared with the conventional bolted structure. In addition, the need for bolting a large number of locations is eliminated. In particular, when a large mass body 20 is used as in the present embodiment, according to the present embodiment, the bolting integral with the closing plate requires a large number of bolting locations. Such trouble can be remarkably reduced.

Further, since most of the dynamic damper 8 is built in the closed space 12, the internal closed space 12 can be used as a space for disposing the dynamic damper 8, and the dynamic damper 8 after the mounting is securely mounted. Can be prevented from falling off.

Therefore, the closed space 12 of the vehicle body member 1, which was originally a dead space, can be effectively used as a space for disposing the dynamic damper 8, and the degree of freedom in laying out the dynamic damper 8 increases.

That is, since the portions of the dynamic damper 8 such as the bolts 21 and the nuts 22 that protrude from the vehicle body member 1 are small, even if the engine 6 and the like are supported on the vehicle body member 1, the bottom portion thereof And the dynamic damper 8 do not interfere with each other.

In addition, since the mounting position of the dynamic damper 8 is substantially in the middle of the vehicle body member 1 in the longitudinal direction, even if vibrations occur in the vehicle body member 1 at both ends in the longitudinal direction as fixed ends, the vibrations are just generated. Since the dynamic damper 8 is located at the antinode, this vibration can be efficiently damped. In addition, since the dynamic damper 8 is built in, it can be mounted at such an optimum position.

Further, since the insulator 16 and the mass body 20 constituting the dynamic damper 8 can be separated, various combinations of the spring constant K of the damper elastic body 19 and the mass M of the mass body 20 can be facilitated. Tuning becomes easy.

The vehicle body member according to the present invention is not limited to the above-described embodiment, and can be variously modified. For example, the member on which the insulator 16 is mounted may be the closing plate 11. Further, as shown by the phantom line in FIG. 1, it is also possible to temporarily fix the mounting portion of the insulator 16 at another location, for example, at one center of the mass body 20.

Since the dynamic damper 8 is constituted by a combination of a damper elastic body and a mass body, the damper elastic body is not necessarily required to have a configuration like the insulator 16 and is provided with at least only the damper elastic body 19. If the insulator 16 is used, various known structures other than the cylindrical type as in the embodiment can be used, and the number thereof is also free. The large mass body 20 as in the embodiment must be used. If there is only one.

The floating support of the dynamic damper 8 does not necessarily have to be located at the substantially middle portion in the longitudinal direction of the vehicle body member 1, and can be completely accommodated in the closed space 12.

Further, the size of the mass body 20 can be freely set according to the purpose of use, and can be independently provided for each damper elastic body. However, in any case, the mass body 20 is larger than the opening 28 and the damper elastic body mounting hole 14. In addition, the coating of the mass body 20 is not always necessary, and if not, the plating process is not necessary.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a vehicle body member according to an embodiment;

FIG. 2 is a schematic view showing an example of using a vehicle body member.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional view showing a temporary fixing step.

FIG. 5 is a sectional view showing the same and the painting process.

FIG. 6 is a sectional view showing a final fixing step.

[Explanation of symbols]

1: body member, 8: dynamic damper, 10: main body, 11: closing plate, 12: closed space, 1
4: Damper elastic body mounting hole, 15: collar, 16: insulator, 19: damper elastic body, 20: mass body, 21:
Bolt, 22: nut

Claims (4)

[Claims] 1. A hollow member having a closed space formed therein by a main body having an open cross section and a closing plate covering an open portion of the main body, wherein a dynamic damper is accommodated in the closed space and both ends in a longitudinal direction. In the method of manufacturing a vehicle body member in which a portion is attached to a vehicle body, a temporary fixing step of supporting the mass body without passing through the damper elastic body to the closing plate or the main body before welding the closing plate to the main body, A welding process of covering the opening of the main body with a closing plate and welding the main body and the closing plate to form a closed space, a painting process of painting the main body and the closing plate after this welding process, and a temporary fixing after painting. After removing the member, a damper elastic body is attached to the main body or the closing plate, and the damper elastic body is Preparation of the vehicle body member having a dynamic damper, wherein a mass body and a final supporting step to float supporting Te. 2. The temporary fixing step according to claim 1, wherein in the temporary fixing step, the mass body is temporarily fixed by using a damper elastic body mounting hole provided in advance in the main body or the closing plate. A method of manufacturing a vehicle body member having a dynamic damper. 3. In the temporary fixing step, the mass body and the main body or the closing plate supporting the mass body are mounted so as to be conductive, and in the subsequent welding step, the main body, the closing plate and the mass body are simultaneously electrostatically coated. A method of manufacturing a vehicle body member having a dynamic damper according to claim 1, wherein: 4. A method for manufacturing a vehicle body member having a dynamic damper according to claim 3, wherein a portion not painted by said temporary fixing is plated in advance.