JPH07267137A - Vibration reducing structure of car body having chassis frame - Google Patents

Abstract

PURPOSE:To enable suitable setting of distribution of rigidity and so on to a chassis frame and suitably and stably support the whole of an upper body on the chassis frame even in the case where the total lengths of the upper body including a cabin and a chassis frame are substantially equal to each other, and in the case where the upper body is extended from the central part of the chassis frame to the front end part or the rear end part. CONSTITUTION:A chassis frame 1 is formed by a double structure comprising a frame part 1a which is formed by the central part 7b of a side frame 7 and front and rear elastic parts 5 formed consecutively on the front and rear parts 7a, 7c of the central part 7b, and the rigidity and so on of which are relatively small, and a rigid part 6 formed to be connected to the frame part la, and the weight and rigidity of which is larger than those of the elastic parts 5 in the range of the length of the upper body 2 which amounts to the total length in the longitudinal direction of a car body. A mount member 13 for elastically supporting the upper body 2 is installed on each of the elastic parts 5, and a suspension fitting part 14 is provided on the rigid part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION In the present invention, at least one of the weight and rigidity of a front portion and a rear portion having a suspension mounting portion of a chassis frame is set to be larger than that of a central portion between these front and rear portions. At the same time, the present invention relates to a vehicle body vibration reduction structure including a chassis frame in which an upper body including a cabin is elastically supported at a central portion of the chassis frame via a mount member.

[0002]

2. Description of the Related Art Conventionally, a vehicle structure having a chassis frame has been adopted for a truck or the like which has a heavy load and is required to withstand such a large load. When carrying a load that is several times the weight of the vehicle body on the loading platform, so that bending, distortion, vibration, etc. that occur in the vehicle body structure act on the upper body and there is no problem in maneuverability, A tough chassis frame receives these flexures and the like, while the upper body including the cabin on which an occupant rides is mounted and supported separately on the chassis frame by a mount member. As described above, for the conventional vehicle body structure having the chassis frame, the vehicle body design with emphasis on load bearing has been performed.

[0003]

By the way, in recent years, the required performance of the truck body is not limited to the above load-bearing capacity, but the demand for comfort such as low vibration and quietness is also increasing. Nowadays, when the vehicle body structure with the chassis frame is applied to the basic structure as a leisure vehicle, it is extremely important to ensure comfort in the vehicle body structure with the chassis frame. However, in the body structure with chassis frame, the original performance required for this body structure different from the monocoque structure itself and the history of its development are premised on satisfying the load resistance, and on top of that, low vibration Although the proposal of Japanese Utility Model Laid-Open No. 61-129678 and the like is known in consideration of the noise and quietness, sufficient vibration isolation performance has not been secured.

The inventor of the present application has been researching various measures for ensuring a good vibration isolation performance for a cabin with respect to a chassis frame-equipped vehicle body structure for supporting an upper body thereon. There is an idea that the vibrations on the chassis frame side cancel out the vibrations on the cabin side by properly linking the generated vibrations and the vibrations generated in the cabin. Both the chassis frame and the upper body including the cabin have unique physical quantities such as weight, spring constant, and rigidity, and have unique vibration characteristics. Therefore, it is possible to adjust the vibration characteristics of the chassis frame and the upper body by appropriately distributing rigidity and weight to the chassis frame and the upper body so that the vibrations are linked to each other. Yes, this can improve the vibration isolation performance for the cabin.

When the rigidity of the chassis frame and the upper body is appropriately distributed in this way to ensure the linking action of the vibrations generated therein and suppress the vibrations of the cabin, the vibrations of the cabin are almost centered in the front-rear direction. It is necessary to configure the chassis frame so that an amplitude corresponding to the vibration amplitude of the cabin in which it is located is obtained in the central part of the chassis frame corresponding to this cabin position, i.e. the rigidity of the central part of the chassis frame is It is necessary to set the cabin smaller than the front and rear portions, and it is necessary to support the cabin only in the central portion of this chassis frame in which such a correspondence relationship is set. If such a supporting structure is not ensured, that is, unless the cabin is supported only by the central portion of the chassis frame, the correspondence relationship set as described above cannot be ensured and an effective vibration reduction effect cannot be obtained. For example, the overall length of the upper body including the cabin in the front-rear direction of the vehicle body is sufficiently shorter than the overall length of the chassis frame. Therefore, in a vehicle body structure in which the cabin can be supported only by the central portion of the chassis frame, the elastic vibration amplitude in the central portion of the chassis frame is sufficient. In addition, since the cabin can be stably supported only in the central portion, it is possible to achieve sufficient vibration reduction. However, on the other hand, when the upper body and the chassis frame are almost the same in total length, or in the vehicle body structure in which the upper body reaches the front end portion from the central portion of the chassis frame, it is difficult to secure the above supporting configuration. As a result, it is not possible to obtain an appropriate vibration coordinating action, and it is difficult to stably support the entire upper body with a length comparable to that of the entire chassis frame whose rigidity is changed in its entire length, and it is difficult to support the upper body. There is a problem that vibration is easily induced unless the chassis frame is properly supported.

The present invention has been made in view of the above problems, and its object is to provide a case where the upper body including the cabin and the chassis frame have substantially the same total length, or the upper body has a chassis frame. Even when reaching the front end or the rear end from the center part, it is possible to appropriately and stably support the entire upper body with respect to this chassis frame while enabling appropriate setting of rigidity distribution to the chassis frame. It is an object of the present invention to provide a vibration reducing structure for a vehicle body, which is provided with a chassis frame that can be used.

[0007]

According to the present invention, at least one of weight and rigidity of a front portion and a rear portion having a suspension mounting portion of a chassis frame is set larger than that of a central portion between the front and rear portions. In addition, the upper body including the cabin is elastically supported at the center of the chassis frame via a mount member, and the front and rear portions of the chassis frame have the weight and rigidity of the chassis frame. Of the elastic part formed substantially in the same way as the central part of the elastic part, and a rigid part that is formed in series on the elastic part and has at least one of its weight and rigidity set larger than the elastic part. A mount member mounting portion having a heavy structure, a suspension mounting portion is formed on the rigid portion, and the elastic body elastically supports the upper body on the elastic portion. Characterized in that it is formed.

Further, the double structure is constituted by a folded structure in which the rigid portion is folded with respect to the elastic portion.

[0009]

According to the present invention, at least one of the weight and rigidity of the front portion and the rear portion of the chassis frame having the suspension mounting portion is set larger than that of the central portion between the front and rear portions, and the cabin is Including the body structure in which the upper body, including the upper body, is elastically supported at the center of the chassis frame via a mount member, which is a unique configuration intended to reduce vibration input to the cabin, the overall length of the upper body and chassis frame is almost the same. And a vehicle body structure in which the upper body reaches the front end portion or the rear end portion from the central portion of the chassis frame. As described above, by appropriately distributing the weight and the rigidity of the chassis frame, specifically, the rigidity and the like of the front and rear portions of the chassis frame are increased, and the rigidity and the like of the central portion are decreased, which causes the chassis frame. It is possible to suppress the vibration input to the cabin by linking the vibration with the vibration of the upper body, but in this case, it is necessary to support the upper body only in the central portion of the chassis frame having small rigidity. That is, when the length of the chassis frame is sufficiently longer than the length of the upper body including the cabin in which the vibration should be suppressed, and the upper body can be supported only by its central portion, the above vibration reducing effect is effective. Obtainable. However, in the case where the length of the upper body extends over the entire length of the chassis frame or the like, in order to firmly support the upper body on the chassis frame, it is necessary to support the upper body also on the front and rear portions of the chassis frame. However, supporting the upper body only at the central portion of the chassis frame is insufficient in terms of vibration countermeasures and ensuring stability.

In the present invention, the length of the chassis frame is set to be substantially longer than the total length of the cabin while apparently being within the total length of the cabin. Such a structure is achieved by the double structure of the chassis frame. The front and rear parts of the chassis frame have a double structure with an elastic part formed with the same weight as the center part and a rigid part formed in series on this elastic part, the weight etc. being larger than the elastic part. The chassis frame has a structure in which the elastic part and the center part are continuous from the front end part to the rear end part of the chassis frame, and the rigid part is set in series at the front end part and the rear end part of this frame structure in a double structure. Then, the upper body is elastically supported by the elastic portion and the central portion of the chassis frame via the mount member, and the front and rear suspensions are attached to the rigid portions at the front and rear portions. With this, even if the upper body and the chassis frame have almost the same length, the chassis frame is
Since the length of the chassis frame is sufficiently longer than the length of the upper body because it is longer than the upper body by the lap of the double structure, the upper body is supported only in the center part of the body. Therefore, it is possible to effectively exhibit the vibration reducing action due to the linking action of the vibrations, and it is possible to properly and stably support the upper body over the entire chassis frame. That is, for a vehicle model in which the upper body and the chassis frame have the same length, it is possible to preferably introduce a rigidity / mass distribution method that improves vibration isolation, which is achieved by a vehicle body structure in which the chassis frame is longer than the upper body, and is quiet. Can be improved.

Further, by forming the double structure in a folded structure in which the rigid portion is folded back with respect to the elastic portion, the elastic portion and the rigid portion can be positioned in parallel vertically and horizontally,
It is possible to easily set the mount member mounting portion and the suspension mounting portion that elastically support the upper body in each elastic portion and rigid portion without occupying a large space for disposing the chassis frame.

[0012]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In this embodiment, basically, at least one of the weight and rigidity of the front portion 7a and the rear portion 7c having the suspension mounting portion 14 of the side frame 7 constituting the chassis frame 1 is the front / rear portion 7.
The vehicle body structure is set to be larger than the central portion 7b between a and 7c, and the upper body 2 including the cabin 15 is elastically supported by the central portion 7b of the side frame 7 via the mount member 13. Front part 7a of the side frame 7
Also, the weight and rigidity of the rear portion 7c are equal to those of the side frame 7
An elastic portion 5 formed substantially the same as the center portion 7b of the elastic portion 5, and a rigid portion 6 formed in series on the elastic portion 5 and at least one of weight and rigidity of which is set larger than the elastic portion 5. The suspension mounting portion 14 is formed on the rigid portion 6, and the mount member mounting portion 17 that elastically supports the upper body 2 is formed on the elastic portion 5.

The double structure is formed by folding back the rigid portion 6 with respect to the elastic portion 5.

The basic structure of this embodiment and the concept of its operation will be described with reference to FIGS. As shown in FIGS. 1 and 2, the chassis frame 1 corresponds to the central portion and the attachment points of the suspensions 3 and 4 in the length range corresponding to the upper body 2 having the length extending in the longitudinal direction of the vehicle body. A frame portion 1a composed of front and rear elastic portions 5 formed in series at the front and rear portions of the central portion and having a relatively small rigidity, and the frame portion 1a are formed in series.
It has a double structure including a rigid portion 6 having a weight and rigidity larger than that of the elastic portion 5.

In detail, as shown in FIG. 2, the chassis frame 1 is basically provided with a pair of left and right side frames 7 arranged along the front-rear direction of the vehicle body, and bridged between the side frames 7. It is composed of a front frame 8 at the front end of the vehicle body, a rear frame 9 at the rear end of the vehicle body, and a cross frame 10 arranged between the front frame 8 and the rear frame 9 at a distance from each other.

Particularly, the front portion 7a and the rear portion 7c of the side frame 7 are an inner frame 11 which functions as an elastic portion 5 having a central portion 7b extended as it is, and a rigid portion 6 which surrounds the inner frame 11 from the outside. The outer frame 12 and the functioning outer frame 12 constitute a double pipe structure. These frames 11 and 12 are formed in the shape of a hollow cylinder, and the outer frame 12 is formed to have a larger cross-sectional area than the inner frame 11. The outer frame 12 constitutes a portion of the series of side frames 7 having high rigidity and the like, and the inner frame 11 constitutes a portion of the side frame 2 having low rigidity and the like corresponding to the central portion 7b. Further, the outer frame 12 and the inner frame 11 are joined at the front end portion and the rear end portion of the vehicle body and are continuous in structure. A mount member 13 that elastically supports the upper body 2 on the inner frames 11 is provided.
And a suspension attachment portion 14 is provided on the outer frame 12.

The chassis frame 1 having such a form is
It has a property equivalent to that shown in FIG. By appropriately distributing the weight and rigidity of the chassis frame 1, that is, by increasing the rigidity of the front portion 7a and the rear portion 7c of the side frame 7 and decreasing the rigidity of the central portion 7b, the vibration generated in the chassis frame 1 It is possible to suppress the vibration input to the cabin 15 by linking it with the vibration of the upper body 2 having the cabin 15, but in this case, the upper body 2 should be supported only by the central portion 7b of the side frame 7 having a small rigidity or the like. is necessary. As in the configuration shown in FIG. 3, the length of the chassis frame 1 is sufficiently longer than the length of the upper body 2 whose vibration is to be suppressed, and the upper body 2 is supported only by the central portion 7b of the side frame 7. When it is possible, the vibration reducing effect can be effectively exhibited.

However, in the case where the length of the upper body 2 extends over the entire length of the chassis frame 1 as in the vehicle body structure shown in FIG. 1, in order to firmly support the upper body 2 on the chassis frame 1, The upper body 2 is also provided at the front portion 7a and the rear portion 7c of the side frame 7.
It is necessary to support the upper body 2 only by supporting the upper body 2 only at the central portion 7b of the side frame 7 in terms of vibration countermeasures and ensuring stability.

Therefore, in the present embodiment, the length of the chassis frame 1 is apparently set within the entire length range of the upper body 2 while being substantially longer than the entire length of the upper body 2. ing. Such a structure is achieved by the double structure of the side frame 7.

FIG. 4 shows an example of the vibration state of the chassis frame 1 of this double structure. The inner frame 11 (elasticity) of the side frame front portion 7a and the rear portion 7c having the same performance as the central portion 7b is shown. The portion 5) vibrates with the same vibration characteristics as the central portion 7b, while the outer frame 12 (rigid portion 6) coupled to the inner frame 11 is vibrated.
Vibrate with vibration characteristics similar to those of the front portion 7a and the rear portion 7c having large rigidity shown in FIG. 3 above, and substantially secure the vibration mode when the chassis frame 1 is longer than the upper body 2. be able to.

As a result, when the length of the upper body 2 reaches the entire length of the chassis frame 1, or when the upper body 2 reaches the front end portion or the rear end portion from the central portion of the chassis frame 1. Even if the vehicle body structure is not enough to support the upper body 2 only at the central portion thereof with respect to the chassis frame 1, it is necessary to secure the supporting portion of the upper body 2 over the entire length range of the chassis frame 1. It is possible to provide the chassis frame 1 with a portion having a large rigidity and the like, and it is possible to ensure reduction of vibration input to the cabin 15.

In this embodiment, since the inner frame 11 can be housed in the outer frame 12, the chassis frame 1 can be made compact while having a double structure.

Specific examples will be described below. What was shown in FIG.5 and FIG.6 is an example of the said double pipe structure.
The front portion 7a and the rear portion 7c of the side frame 7 are the central portion 7
It is composed of an inner frame 11 as an elastic portion 5 extending in a series from b and an outer frame 12 as a rigid portion 6 surrounding the outer side of the inner frame 11. As for the front portion 7a, as shown in FIG. 5, the front end portion of the inner frame 11 and the front end portion of the outer frame 12 are joined to each other, and the rear end portion of the outer frame 12 and the rear end portion of the inner frame 11 are connected to each other. A cushioning material 16 such as a mule for absorbing impact is provided between
A gap is formed between them. A suspension attachment portion is provided on the outer frame 12, and a mount member attachment portion 17 for elastically supporting the upper body 2 is provided at the front end of the central portion 7b of the side frame 7.

On the other hand, with respect to the rear portion 7c, as shown in FIG. 6, the outer frame 12 is attached to the inner frame 11 while ensuring a clearance.
The front end of the outer frame 12 and the inner frame 11
A cushioning material 16 such as a mule is provided between the front end of the and.
A leaf spring type suspension mounting portion 14 is provided at the rear end of the central portion 7b of the side frame 7 and the rear portion of the outer frame 12, and the central portion 7b is provided.
A mount member attachment portion 17 that elastically supports the upper body 2 is provided at the rear end of b.

With this structure, the upper body 2 and the like that secures the above-mentioned action and reaches the entire length of the chassis frame 1 can be stably provided over the entire chassis frame 1 while ensuring a desired vibration reduction effect. Can be supported.

7 to 9, in the front portion 7a and the rear portion 7c of the side frame 7 constituting the chassis frame 1, the rigid portion 6 is folded back with respect to the elastic portion 5 to form them in parallel. It is a thing. In the side frame 7 having the same structure as that described above, the rigid portion 6 is formed by folding back the elastic portion 5 having substantially the same performance as the central portion 7b. Further, a cushioning material 16 for absorbing impact is provided between the ends of the rigid portion 6 and the elastic portion 5, and a gap is formed between them.

With this structure, the mount member mounting portion 17 for elastically supporting the upper body 2 can be easily set to the upper elastic portion 5 facing the lower surface of the upper body 2, and the suspension mounting portion 14 can be used for the suspension. It can be easily set to the lower rigid portion 6 facing the 3 and 4 sides.

The structure shown in FIG. 10 is provided with a rear body 18 used as a luggage carrier. In such a structure, the rigid portion 6 may be folded back upward.

The embodiment shown in FIGS. 11 and 12 is
The folded structure is horizontal. In this case, the cushioning material 16 is horizontally provided between both the rigid portion 6 and the elastic portion 5. In this example, it is possible to prevent the vehicle height from increasing due to the folding back of the chassis frame 1.

[0030]

In summary, according to the present invention, at least one of the weight and rigidity of the front and rear portions of the chassis frame having the suspension mounting portion is set to be larger than that of the central portion between the front and rear portions. At the same time, the upper body including the cabin is elastically supported at the center of the chassis frame via a mount member, which is a unique structure designed to reduce vibration input to the cabin. The rear part and the rear part are formed in a series with an elastic part whose weight and rigidity are approximately the same as those of the central part of the chassis frame, and a series of parts are formed in the elastic part. It has a double structure consisting of a large set rigid part, the suspension mounting part is formed on the rigid part, and the upper body is elastically mounted on the elastic part. Since the mounting member mounting part to support is formed, the length of the chassis frame can be set to be substantially longer than the entire length of the cabin while apparently fitting within the entire length range of the cabin, and the length of the upper frame and the chassis frame can be set. Regarding the vibration, even if the total length is almost the same, the chassis frame is longer than the upper body by the amount of double-wrapped wrap, so the length of the chassis frame is sufficiently longer than the length of the upper body. The vehicle body can be configured in an ideal form in which only the center part is supported, and the vibration reduction effect due to the linking action of the vibrations can be effectively exerted, and the upper body is appropriate over the entire chassis frame. And it can be stably supported. That is, for a vehicle model in which the upper body and the chassis frame have the same length, it is possible to preferably introduce a rigidity / mass distribution method that improves vibration isolation, which is achieved by a vehicle body structure in which the chassis frame is longer than the upper body, and is quiet. Can be improved.

Further, by forming the double structure with a folded structure in which the rigid portion is folded with respect to the elastic portion, the elastic portion and the rigid portion can be positioned in parallel vertically and horizontally,
It is possible to easily set the mount member mounting portion and the suspension mounting portion that elastically support the upper body in each elastic portion and rigid portion without occupying a large space for disposing the chassis frame.

[Brief description of drawings]

FIG. 1 is an exploded side view showing a vehicle body structure in an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing the chassis frame structure of FIG.

FIG. 3 is an explanatory diagram showing an example of a vibration state based on ideal distribution of rigidity and the like.

FIG. 4 is an explanatory diagram showing an example of a vibration state obtained by the vehicle body structure according to the present invention.

5 is a partially cutaway side view showing the structure of the front portion of the side frame in FIG. 1. FIG.

6 is a partially cutaway side view showing the structure of the rear portion of the side frame of FIG.

FIG. 7 is an exploded side view showing a vehicle body structure according to another embodiment of the present invention.

8 is a schematic plan view showing the chassis frame structure of FIG. 7. FIG.

9 is a schematic side view showing the chassis frame structure of FIG. 7. FIG.

FIG. 10 is an exploded side view showing a vehicle body structure according to another embodiment of the present invention.

FIG. 11 is a schematic plan view showing a chassis frame structure according to another embodiment of the present invention.

12 is a schematic side view showing the chassis frame structure of FIG.

[Explanation of symbols]

 1 chassis frame 2 upper body 5 elastic part 6 rigid part 7 side frame 7a side frame front part 7b side frame central part 7c side frame rear part 13 mount member 14 suspension mount part 15 cabin 17 mount member mount part

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuhiro Nakamura 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (2)

[Claims] 1. An upper part including a cabin, wherein at least one of weight and rigidity of a front part and a rear part having a suspension attachment part of a chassis frame is set to be larger than a central part between the front and rear parts. A body structure in which a body is elastically supported on a central portion of the chassis frame via a mount member, and a front portion and a rear portion of the chassis frame are formed so that weight and rigidity thereof are substantially equal to those of the central portion of the chassis frame. And a rigid portion that is formed in a series on the elastic portion and has at least one of weight and rigidity set to be larger than that of the elastic portion. A suspension mounting portion is formed on the upper portion, and a mount member mounting portion that elastically supports the upper body is formed on the elastic portion. Vibration reduction structure of the vehicle body provided with a chassis frame that. 2. The vibration reducing structure for a vehicle body having a chassis frame according to claim 1, wherein the double structure is a folded structure in which the rigid portion is folded with respect to the elastic portion. .