JP2003327157A - Body frame structure for vehicle with special equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a low-strength zone and a stress concentration portion by eliminating cross-sectional change ranging over a back part of a cab in a body frame and between it and a rear end edge therein, and to preclude the body frame from being deformed even when excessive bending or torsional moment acts on the body frame, in body frame structure for a dump truck mounted with a dump box on the body frame fixed with a sub-frame on a chassis frame. <P>SOLUTION: A front end part of the sub-frame 2 fixed on the chassis frame 1 mounted with the cab 3 in its front part is extended up to an under side of the cab 3, an extended part therein is fixed to a cab mount arch 19 fixed onto a backface of the cab 2. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which a subframe is integrally coupled on a palm frame having a cab mounted on the front portion, and a dump load is placed on the subframe. The present invention relates to a body frame structure of a specially equipped vehicle in which a specially mounted body such as a box or a liquid tank is mounted. [0002] Conventionally, in specially equipped vehicles such as dump trucks and tank trucks, a sub-frame is integrally joined to an existing coconut frame of a freight vehicle, and the coconut frame is reinforced, and the sub-frame is mounted on the sub-frame. Large special equipment such as dump boxes and liquid tanks are installed. However, in the conventional specially equipped vehicle such as a dump truck, as shown in FIG. 6, a cab is mounted on the front part of the palm frame, and a dump box is mounted on the subframe on the palm frame. A slight gap D is provided between the back surface of the cab and the front end of the subframe, and when the specially-equipped vehicle is running, the static force applied to these frames due to bending and torsional moments acting on the palm frame and the subframe, Dynamic and static + dynamic bending moment distributions are generally as shown in FIG. In FIG. 6, in the A zone below the cab, since the cab is mounted on the palm frame, the cab compensates for the strength of the front portion of the palm frame and increases its rigidity. In addition, in the C zone where the dump packing box is mounted, a hoist device (not shown) for tilting the dump packing box is provided in the subframe, While the rigidity of the body frame composed of the subframe can be increased, in the B zone substantially corresponding to the gap D, there is no reinforcing means for the palm frame,
When the dump truck travels on a rough road or the like and an excessive bending or twisting moment acts on the body frame, it is considered that an excessive load acts on the palm frame in the B zone and deforms it. In particular, at the front edge of the sub-frame, there is a problem that stress concentration is generated in the body frame due to a sudden cross-sectional change. Therefore, in the prior art, for example, as shown in FIG. 7A, the front end of the sub-frame is opened in a side view in order to reduce the rigidity of the front end of the sub-frame. Or a forcibly inclined surface on the lower surface of the front end portion of the subframe, as shown in FIG. 4B, and a subframe as shown in FIG. In order to prevent a sudden change in the cross section of the vehicle body frame, for example, an inclined surface that rises forward is provided on the upper surface of the front end of the vehicle body. [0006] However, the conventional measures described above require a special process on the front end of the sub-frame formed of a steel material or the like, resulting in high costs. In addition, there is a problem that it is not sufficient for the B zone of the body frame to have a desired strength. The present invention has been made in view of the above circumstances, and does not apply special processing to the subframe, eliminates a change in the cross section of the body frame made up of the coconut frame and the subframe, and further the entire body frame. An object of the present invention is to provide a body frame structure for a specially equipped vehicle that solves the above-mentioned problems by increasing the strength of the vehicle. In order to achieve the above-mentioned object, the present invention as claimed in claim 1 is characterized in that a coconut frame having a cab mounted on the front portion and a coconut frame behind the cab. A vehicle body frame structure of a specially equipped vehicle in which a vehicle body frame is configured by a subframe integrally coupled to the vehicle body, and a special body is mounted on the subframe, and the front end portion of the subframe is connected to the cab. The extension of the subframe is integrally connected to the cab mount arch provided integrally with the back of the cab, and according to such a feature, The body frame, which consists of the subframe and the subframe, eliminates the cross section change between the back of the cab and the rearmost end of the cab. Therefore, the vehicle body frame will not be deformed even if an excessive bending or twisting moment acts on the vehicle body frame due to a bad road traveling of the specially equipped vehicle.
In addition, the manufacturing cost of the front end portion of the subframe can be reduced by eliminating the need for special processing as in the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on embodiments of the present invention illustrated in the accompanying drawings. In this embodiment, the body frame structure of the present invention is applied to a dump truck. FIG. 1 is a side view of the dump truck having the body frame structure of the present invention, and FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, FIG. 4 is a partial plan view taken along arrow 4 in FIG. 2, and FIG. 5 is taken along line 5-5 in FIG. It is a partial expanded sectional view which follows. In FIG. 1, a cab-over type dump truck V has a cab (cab) 3 mounted on the front portion of the palm frame 1, and a subframe on the palm frame 1 behind the cab 3. 2 are integrally coupled, and the body frame F is configured by the palm frame 1 and the sub-frame 2. As usual, a traveling engine (not shown) is supported immediately below the front cab 3 of the palm frame 1, and front and rear wheels Wf and Wr are suspended in front and rear of the palm frame 1. The rear wheels Wr are respectively suspended by means, and are linked and connected to the engine. On the sub-frame 2, a dump box 4 as a special equipment is mounted so as to be tiltable backward with a hinge shaft 5. Next, a vehicle body frame structure according to the present invention will be described in detail with reference to FIGS. 2 to 5. A vehicle body frame F of a dump truck V as a specially equipped vehicle includes an existing palm frame 1 installed in a truck, It is composed of a subframe 2 and a subframe 2 which are integrally joined to the palm frame 1.
As shown in FIG. 5, a pair of vertical frames 7 constituted by arranging a plurality of spacers 7 b on the open part of the cross-sectional channel-shaped frame body 7 a having an open part inside the dump truck V, The spacers 7b are integrally formed by a cross frame 8 to form a rectangular frame in plan view.
Are reinforced by welding the angle member 7c up and down.
On the other hand, in the rear of the cab 3, the sub-frame 2 integrally coupled onto the palm frame 1 is welded to a pair of vertical frames 10 made of a rectangular tube having a square cross section with a plurality of cross frames 11. Thus, it is configured in a rectangular frame shape in plan view. As clearly shown in FIG. 5, the vertical frame 7 of the palm frame 1 and the vertical frame 10 of the subframe 2.
A plurality of U bolts 13 are inserted into the frame so as to sandwich the frames from below at intervals in the longitudinal direction, and are placed on the subframe 2 on the free upper ends of these U bolts 13. By screwing the double nut 15 through the washer 14, the sub frame 2 is integrally coupled to the palm frame 1. In addition, as shown in FIGS. 1 and 2, a plurality of detent members 17 are fixed between the joint portions of the palm frame 1 and the sub frame 2 at intervals in the front-rear direction. A relative shift between the left and right sides and the front and rear sides of the palm frame 1 and the subframe 2 is prevented. As shown in FIGS. 2 to 4, a cab mount arch for reinforcing the back surface of the cab 3 and fixing it to the palm frame 1 is provided at the lower left and right central portions of the back surface of the cab (cab) 3. 19 is fixed. The cab mount arch 19 is configured by fixing a reinforcing plate 21 inside an arch-shaped skeleton 20.
The left and right sides and the upper side of the bracket 19 are welded to the bracket 19.
It is fixed to the back surface of the cab 3 by bolts 22 through a and 19b. The left and right lower portions of the arch-shaped skeleton 20 of the cab mount arch 19 are extended to the outer side surfaces of the left and right vertical frames 7 of the palm frame 1. On the other hand, the left and right vertical frames 10 of the subframe 2 on the palm frame 1
The front end of the subframe 2 extends beyond the back of the cab 3 to the lower side of the cab 3. The left and right lower parts of the skeleton 20 of the cab mount arch 19 are integrally coupled to each other by a plurality of connecting bolts 24 across the outer surface of the part. Therefore, the vehicle body frame F comprising the palm frame 1 and the subframe 2 is
There is no cross-sectional change portion between the back portion of the cab 3 and the rear end portion thereof, thereby eliminating the low-strength zone and the stress concentration portion. As described above, the front end portion of the sub-frame 2 on the coconut frame 1 extends forward from the back surface of the cab 3, and the extension portion together with the coconut frame 1 forms a cab mount on the back surface of the cab 3. By integrally connecting to the arch 19, the stress concentration point existing in the front edge of the low-strength zone B and the subframe 2 in the zone B shown in the conventional example of FIGS. 7 and 8 can be eliminated. Even if an excessive bending or torsional moment is applied to the vehicle body frame F due to traveling on a rough road or the like, a stress concentration portion is not generated in the vehicle body frame F, or it is not deformed. Further, the manufacturing cost of the front end portion of the subframe 2 can be reduced by eliminating the need for special processing as in the prior art. Although one embodiment of the present invention has been described above, the present invention is not limited to that embodiment, and various embodiments are possible within the scope of the present invention. For example, in the above embodiment, the case where the body frame structure of the present invention is applied to a dump truck has been described, but this is provided with a sub-frame of another specially equipped vehicle such as a tank truck, a concrete mixer truck, and a garbage truck. Of course, it can also be applied to the body frame. As described above, according to the first aspect of the present invention, the vehicle body frame composed of the palm frame and the sub-frame has a cross section between the back portion of the cab and the rearmost end portion thereof. This eliminates the changing part, which eliminates the low-strength zone and stress-concentrated areas, so that the body frame can be deformed even if excessive bending or torsional moments are applied to the body frame due to rough roads on specially equipped vehicles. There is nothing to do. Further, the manufacturing cost of the front end portion of the subframe can be reduced by eliminating the need for special processing as in the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a dump truck having a vehicle body frame structure according to the present invention. FIG. 2 is an enlarged view of a portion surrounded by an imaginary line in FIG. FIG. 4 is a partial plan view taken along line 4 in FIG. 2. FIG. 5 is a partially enlarged sectional view along line 5-5 in FIG. 2. FIG. 6 is a side view of a conventional dump truck and its body frame. FIG. 7 is a partial side view showing a state of connection between the front end portion of a sub-frame and a palm frame. DESCRIPTION OF SYMBOLS Palm frame 2 ... Subframe 3 ... Cab 4 ... Special equipment (dump box) 19 ... ..Cab mount arch

Claims (1)

What is claimed is: 1. A palm frame (1) having a cab (3) mounted on a front portion thereof, and a coconut frame (1) connected integrally to the palm frame (1) behind the cab (3). A vehicle body frame structure of a specially equipped vehicle, in which a vehicle body frame (F) is constituted by the subframe (2), and a specially mounted body (4) is mounted on the subframe (2). 2) the front end of the cab (3)
Extend the front of the back of the subframe (2)
A vehicle body frame structure for a specially equipped vehicle, characterized in that an extended portion of the vehicle is integrally coupled to a cab mount arch (19) integrally provided on the back surface of the cab (3).