JPS5873479A - Framing construction of car body - Google Patents

Abstract

PURPOSE:To reduce deformation and vibration of a car body and also noises caused thereby by shortening the space of the coupling part of the strength member of wheel house with the pillar on the cabin side. CONSTITUTION:A wheel house's upper frame 24 as strength member is formed with downward inclination to the cabin 25 side from the neighborhood of the part just over the center of the wheel 27, and coupled approx. at the central part Q' of the pillar 26 situated at the part of contact between the engine room 21 and cabin 25. That is to say, the space P'Q' of the coupling part between the upper and lower strength members 24, 22 supporting the static or dynamic load of the engine room 21 and the pillar 26 of the cabin 25 is shortened as much as possible with the condition maintained that the strength of the car body is not impaired.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automobile body frame structure K14I, particularly a joint structure #Ic141 between an engine room and a passenger compartment that reduces vibration and noise of the vehicle body in the engine idling rotation range. In recent years, there has been a shift towards making automobiles more compatible with the energy-saving era (F゛F (7a front engine front drive)) and making them lighter, mainly in small cars manufactured by automobile companies, with FF@equipment engine cars becoming the mainstream. Although FF transverse engine vehicles have advantages such as a more compact engine room and a simpler engine power transmission mechanism, they are susceptible to low-frequency vibrations in the pitching direction in the engine idle rotation range. There are latent problems such as noise in the vehicle interior and slight vibrations in the steering wheel.Under these circumstances, the technical issues that need to be solved are not only the value of the FF transverse engine vehicle as an economical vehicle, but also the engine idle. The purpose of this invention is to reduce vibration and noise in the rotation range, and provide a more refreshing ride.The inventors of this invention have clarified this behavior and tried to improve the icing and vibration sound of the vehicle. It provides:

First, to explain the connection structure between the engine room and the passenger compartment that has been generally adopted in the past, the following is the partial order shown in Fig. and the wheel house upper frame, which is a strength member in the longitudinal direction of the upper part of the wheel house 6, is 4,541>')-k-A, and the side frame 2 is a pillar erected at the corner of the passenger compartment 5. 6 lower P
The upper foil house upper frame i 4 is coupled to the pillar 6 at a point Q that is approximately at the same height as the top of the foil house 3 . That is, it is connected to the pillar 6, which is a vertical member of the passenger compartment 5, with a maximum distance PQ that approximately corresponds to the height of the strength member 2 and the four-piece wheel house 3 that support the static or dynamic loads of the engine room 1. Here, an example of the engine mount for the FF1ifi engine is shown in a schematic plan view in Figure #12. That is, the left and right side frames 2
, 2, front subframe 7 and rear subframe 8
11IItJ, the center beam 9 was installed in the center of both subframes 7.8, and the engine 10tli70
Front engine mount 11 in the center of the engine support frame 7. It is supported by a rear engine mount 12 in the center of the rear subframe 8 and a side engine mount 13 provided in the side frame 2, and the center beam 9
A wind stopper 14 in the center of
It is now accepted by the government.

In vehicles with FF horizontally mounted engines mounted in this way, they are susceptible to low-frequency vibrations in the pitching direction in the engine's idle rotation range, causing problems such as rattling noise in the vehicle interior and slight vibrations in the steering wheel. ing.

There are various FI methods for simulating the vibrations of rigid structures such as vehicle systems, and one of them is the modal synthesis method that has been attracting attention in recent years. This method #'i First, the vibration system (for example, a car body) is artificially vibrated using a vibrator, etc., the response of each part at that time is determined, and then the vibration mode 2 characteristic parameters are extracted. A vibration system is expressed by several sets of vibration modes and vibration parameters. It is easy to add or remove mass, increase or decrease rigidity, etc. to a mathematical model of such a vibration system (such as a car body), and it is possible to create a mathematical model with structural changes made to the vibration system. If the mounting method is the same, the behavior of the engine is almost unaffected by the structure of the car body, so the engine power will not change due to changes in the structure of the car body, so the force generated during actual use will be transmitted through each mount. Vibration prediction can be performed by measuring the input force and adding the obtained force to the above mathematical model. The inventors of the present invention also conducted a simulation using the above method, and Figure 3 shows the conventional car body frame structure, with the engine mounted as shown in Figure 2, and the deformation and vibration of the car body due to engine vibration being simulated. This is a diagram showing the results of the engine vibration, where the vibration of the engine spreads to the entire vehicle body with the point P at the lower ffl of the pillar 6 as a node, the passenger compartment 5 receives large deformation vibration, and the central tip of the steering wheel S The vertical swing is large.

The purpose of the present invention is to reduce the deformation vibration of the vehicle body originating from the above-mentioned vehicle body frame structure and the noise generated by this, and in order to achieve this purpose, we have developed l of the junction of! To provide a vehicle body frame structure in which the I distance is shortened as much as possible within a range without reducing the strength of the vehicle body.

Embodiments of the present invention will be described below with reference to FIG. 4 and subsequent figures.

FIG. 4 is a partial sacral view showing the coupling structure between the engine room and the passenger compartment according to the present invention, and A-Al/iJ shown in FIG.
The cross-sectional view shows that the engine room 21 has a side frame 22 which is a strength member in the longitudinal direction at the lower part, and a wheel house upper frame 24 which is a strength member in the longitudinal direction at the upper part of the wheel house 23 on both sides of the engine room 21. 1 of the lower side frame 22u vehicle compartment 25.
The fact that it is connected to the lower part P' of the 1M1K pillar 26 is the same as the conventional engine room and single room connection structure shown in FIG. In the present invention, the wheel house upper frame 24 is formed so as to be inclined downwardly toward the passenger compartment from near the center upper part of the wheel 27, and is formed at approximately the central portion Q' of the pillar where the engine room 21 and the passenger compartment 25 contact each other. combined. That is, the distance P' between the connection portion between the upper and lower strength members 24 and 22 that support the static or dynamic load of the engine room 21 and the pillar 26 of the vehicle interior 25.
The car body frame structure is constructed by shortening Q' as much as possible without reducing the strength of the car body. Figure 6 shows the results of simulating the deformation and vibration of the car body due to engine vibration using the same method as in Figure 3, with the engine mounted in the same way as in the case of No. 354 in the car body frame structure configured as K as described above. In this figure, the engine room 21 is vibrated using the lower point P' of the vibration pillar of the engine as a node, but the engine compartment 21 is
The deformation vibration of No. 5 is considerably reduced compared to the conventional vehicle body frame structure shown in No. 5 FIJ, and the swing width of the center tip 8 of the steering handle is also reduced.

Figure 7 is a graph showing the structure of the present invention as a solid line and the conventional structure as a broken line, based on actual measurements of the vibration of the passenger compartment with respect to the engine speeds r, p, and mK, using the vibration acceleration G at the center tip of the steering handle SK. It can be seen that the vibration acceleration at the tip of the steering wheel, that is, the vibration in the passenger compartment when the engine rotates at low speed, is considerably reduced. Figure 8 also shows the sound pressure in the center of the passenger compartment for engine speeds r, p, and m as d.
The graph shown in B shows the structure of the present invention shown by a solid line and the conventional structure shown by a broken line, which shows that the vibration and noise inside the vehicle cabin are alleviated when the engine rotates at low speed.

As described above, in the present invention, the wheel rim is tilted downward Km from near the upper center of the wheel toward the passenger compartment, so that it extends approximately below the center of the pillar at the portion where the pillar contacts the engine room and the passenger compartment. By combining them to form a car body frame structure, it is possible to reduce vibrations and noise in the passenger compartment during low-speed engine rotation and improve ride comfort. @In the case of engine cars, it is effective in alleviating vibrations and noise in the cabin.

In addition, the present invention also applies to a type of wheel eight-wheel upper frame in which 6ff is removed from near the upper center of the wheel to the tip, so that substantially the entire wheel eight-wheel upper frame is tilted downward toward the passenger compartment and connected to the pillar. The present invention can be applied to not only front engines but also rear engines by reducing the distance between the upper and lower strength members supporting the engine compartment and the cabin roof structure to improve the strength of the vehicle body. Of course, the vehicle body frame structure can be constructed by shortening the structure as much as possible without destroying the structure.

[Brief explanation of the drawing]

#11 FI! J is a partial side view showing the conventionally commonly used connecting structure between the engine room and the passenger compartment, Fig. 2 ti
A schematic plan view showing the FF horizontal engine mount, Fig. 3 is a diagram showing the results of simulating the deformation vibration of the car body due to engine vibration in a conventional car body frame structure, and Fig. 4 shows the engine room and passenger compartment according to the present invention. Fig. 5 is a cross-sectional view taken along the line A-A in #i No. 4M, and Fig. 6 is a simulation of the deformation and movement of the car body due to engine vibration in iK in the same way as Fig. 3. Figure 7 is a diagram showing the results obtained by actually measuring the vibration acceleration G at the center tip 8 of the steering wheel for vibrations in a single chamber with respect to engine speeds r, p, and m. The graph shown in s, Figure 8 shows the engine speed r,
It is a graph in which the gong at the center of the vehicle interior is actually measured and shown in dB with respect to p and m, with the structure of the present invention shown as a solid line and the conventional structure shown with a broken line. 1.21...Engine room, 2.22...Side frame, 5.23...Wheel house, 4.24...
・Wheel house upper 7 frames, 5.25...car compartment,
6.26... Hiller-127... Wheel. Applicant E8 Giken Kogyo Co., Ltd. Agent Patent Attorney Toshihiko Watanabe Figure 5 Map 6 r, p, m □ r, p, m -1-1

Claims (1)

[Claims] t A side frame, which is a longitudinal strength member of the lower part of the wheel house, and a wheel house upper frame, which is a longitudinal strength member of the upper part of the wheel house, are arranged on both sides of the engine room, and a pillar stands at the corner of the cabin. In the car body frame structure of the car installed, the above-mentioned foil eight-wheel upper frame is tilted downward from near the center upper part of the wheel toward the passenger compartment, and the pillar of the part where the engine room and the passenger compartment contact A car body frame structure for an automobile, characterized in that it is configured by joining together below a substantially central portion.