JP7725313B2 - Loading platform lifting device, vehicle equipped with loading platform lifting device, and method for manufacturing the vehicle - Google Patents

Description

The present invention relates to a platform lifting device equipped with a parallel link mechanism, a vehicle equipped with the platform lifting device, and a method for manufacturing the vehicle.

A known loading platform lifting device, which is installed at the rear of a vehicle and raises and lowers the loading platform between the ground and the platform, uses two upper and lower arms that form a parallel link mechanism. The base ends of these arms are each rotatable relative to the vehicle frame via supports located below the platform of the vehicle.

The loading platform 97 of a loading platform lifting device (see, for example, Patent Document 1) is raised in the order shown in Figures 5(a) to 5(c). The support portion 93 is composed of a connecting pipe 93a installed across a pair of left and right body frames 91 and brackets 93b fixed to both ends of this pipe 93a. The base end of a lower arm 95 is journaled at the lower portion of the bracket 93b by a lower journal support portion 95a, and the base end of an upper arm 94 is journaled at the upper portion by an upper journal support portion 94a. The tips of the upper arm 94 and the lower arm 95 are connected to upper connecting portion 94b and lower connecting portion 95b of a plate-shaped connecting member 96. A hydraulic cylinder 98 is provided at the base end of the upper arm 94 and the lower arm 95.

A parallel link mechanism is formed by the support portion 93, upper arm 94, lower arm 95, and connecting member 96. When the hydraulic cylinder 98 extends, the load receiving platform 97 supported by the connecting member 96 rises while remaining horizontal. The lower arms 95, which are provided in a pair on the left and right sides in the width direction of the vehicle, have a predetermined durability and holding force for the load receiving platform 97 via arm connecting pipes 99, each of which has its longitudinal direction aligned with the width direction of the vehicle.

In this loading platform lifting device 90, as shown in Figure 5(c), when the loading platform 97 is approximately flush with the floor height of the loading platform 92, the front surface 94c of the upper arm, the front surface 95c of the lower arm, and the front surface 96c of the connecting member 96 on the front side of the vehicle are positioned so as to abut or be close to the loading platform 92.

Japanese Patent Application Publication No. 11-189088

However, the loading platform lifting device, which is configured to raise and lower the loading platform 97 using the parallel link mechanism described above, still has room for improvement in relation to other components installed in the vehicle.

First, the platform lifting device, which is supported via a support section below the loading platform, must share the limited space with the various functional components also located below the loading platform. However, the installation of the platform lifting device onto a vehicle is a task carried out by the vehicle manufacturer (chassis manufacturer) in their own factory after the vehicle has been delivered. Therefore, the vehicle manufacturer must install the platform lifting device in an appropriate location that does not interfere with the function of other existing components, as the vehicle layout has already been largely determined.

Regarding the longitudinal direction of the vehicle, for example, if the position is to avoid interference with the gas exhaust system (muffler) or tail lamp, it is customary to position the support member behind the muffler and forward of the tail lamp.

Next, in terms of the vertical direction, the ground clearance of the loading platform lifting device is determined based on the existing muffler, etc. Specifically, as long as the loading platform lifting device is not positioned significantly lower than the height of the muffler, etc. that serves as the reference, the minimum ground clearance for the entire vehicle will be maintained at a specified level. For this reason, the loading platform lifting device is customarily mounted so that its vertical clearance is approximately the same as that of the muffler, etc.

However, given the growing expectations for reducing environmental impact in recent years, it is expected that new electrified devices will be added to drive loading platform lifting devices. Furthermore, existing mufflers and other components may also need to be improved in function or enlarged in size in order to improve the quality of exhaust gases. Given these circumstances, it is thought that there will be a greater need than ever before to make use of the space below the loading platform and to install loading platform lifting devices with ample ground clearance.

The present invention was made in light of these issues, and aims to provide a cargo platform lifting device that is not based solely on conventional positions, but contributes to slightly increasing ground clearance or making mounted equipment in the area below the cargo platform more compact in response to future changes in vehicle functions, a vehicle equipped with the device, and a method for manufacturing such a vehicle.

The solution according to the present invention is as follows.
The loading platform lifting device includes a pair of fixed support members fixed to a pair of left and right body frames whose longitudinal direction is the fore-and-aft direction of the vehicle, a connecting support member whose longitudinal direction is the width direction of the vehicle and connects the pair of left and right support members, mounting support members attached to the left and right ends of the connecting support members, a pair of left and right pivot arms whose base ends are rotatably connected to the mounting support members, connecting shaft support members on which the distal ends of the pivot arms are journaled, and a loading platform supported by the connecting shaft support members. Each of the pair of left and right pivot arms has an upper arm and a lower arm, and an arm connecting member whose longitudinal direction is the width direction of the vehicle and connects the lower arms is provided, the connecting support member being positioned higher than a muffler attached below the loading platform of the vehicle. As a result, the loading platform lifting device can be mounted on the rear of the vehicle to avoid interference with the muffler.
This design focuses on the fact that a platform lifting device, which includes pivoting arms positioned at the left and right ends of the vehicle in the width direction and a connecting support member between them, occupies a large area below the vehicle platform because the connecting support member is positioned across the entire width of the vehicle. This design effectively utilizes the area between the pivoting arms but without the connecting support member. By positioning the muffler in this area, it becomes possible to utilize the dead space between the platform lifting device and the vehicle's existing muffler, etc. As a result, it is possible to increase the ground clearance of the platform lifting device or compact the mounting area for the platform lifting device in the area below the platform. This design is therefore advantageous for vehicles with low platform heights, where the area below the platform is particularly limited.

In addition, the arm connecting member may be configured to rotate in conjunction with the lifting and lowering of the loading platform while avoiding the tail lamp fixed to the rear of the vehicle, and to be positioned approximately vertically below the connecting shaft support member when the loading platform is approximately flush with the loading platform.

Next, the above-mentioned loading platform lifting device may be mounted on a vehicle having a loading platform mounted on the body frame, a muffler mounted below the loading platform, and a tail lamp fixed to the rear of the body frame.

The present invention also covers a method for manufacturing a vehicle equipped with the following loading platform lifting device.

The method for manufacturing a vehicle equipped with the loading platform lifting device includes a loading platform mounting step for mounting a loading platform on a pair of left and right body frames whose longitudinal direction is the vehicle's fore-and-aft direction; a body frame accessory mounting step for mounting a muffler to the body frame in an area below the loading platform; and a lifting device mounting step for mounting a loading platform lifting device on the body frame after the loading platform mounting step and the body frame accessory mounting step. The lifting device mounting step includes a support part mounting sub-step for mounting a support part to the body frame; a pivot arm mounting sub-step for mounting a pair of left and right pivot arms that can pivot to the support parts; and a loading platform mounting sub-step for supporting the tip ends of the pivot arms on a connecting pivot support member that supports the loading platform. The support member mounting sub-step is characterized in that fixed support members are fixed to each of the pair of left and right body frames, and connecting support members whose longitudinal direction is the vehicle width direction are fixed to the pair of left and right fixed support members so that they are higher than the muffler.

Furthermore, the manufacturing method may include fixing the fixed support member in a position where the muffler and the support portion overlap when viewed from the side of the vehicle in the support portion attachment sub-step.

This invention makes it possible to move the installation height of the entire loading platform lifting device upward (increasing ground clearance) by focusing on the connecting support members, which occupy a large proportion of the area below the loading platform with the vehicle width as the longitudinal direction. Because it utilizes dead space that often occurs with other components (such as an existing muffler) installed below the loading platform, it is useful for increasing the mounting height, which was previously difficult to achieve, and is an invention that can flexibly accommodate future functional changes to the vehicle as a whole.

1 is a perspective view of a rear portion of a vehicle equipped with a cargo receiving lifting device according to an embodiment of the present invention. 1A is a side view of a loading platform lifting device according to an embodiment of the present invention, and FIG. 1B is a rear view of the same loading platform lifting device. 4 is a side view showing the lifting and lowering operation of the loading platform of the loading platform lifting and lowering device according to the embodiment of the present invention. FIG. 1A is a side view of a main part showing a loading platform lifting device according to an embodiment of the present invention, a muffler provided on a vehicle, and a tail lamp; FIG. 1B is a side view of a main part showing a modified example according to an embodiment of the present invention; FIG. 10 is a side view of a conventional loading platform lifting device.

An example of an embodiment of the loading platform lifting device of the present invention will be described using the drawings.

Figure 1(a) is a perspective view of a vehicle equipped with a loading platform lifting device 100 according to this embodiment. The loading platform lifting device 100 is mounted below the loading platform 1 at the rear of the vehicle, and is configured so that the loading platform 3 can be raised and lowered between the ground and the loading platform height by a rotating arm 2.

The cargo bed 1 is mounted on a pair of left and right body frames 4 (main frames 41 mounted on sub-frames 42) with the longitudinal direction of the vehicle running along the front-to-rear direction. Support sections 5 supporting a pair of left and right pivot arms 2 are connected to each body frame 4. The support sections 5 are composed of fixed support members (frame brackets) 51 fixed to the lower portions of the pair of left and right main frames 41 and suspended slightly downward; connecting support members (first connecting pipes) 52 suspended between the left and right frame brackets 51 with the longitudinal direction running along the width of the vehicle; and mounting support members (mounting members) 53 fixed to both ends of the first connecting pipes 52 and extending upward and downward. As shown in the figure, the first connecting pipes 52 have a length approximately equal to the overall width of the cargo bed 1.

A freely rotatable pivot arm 2, consisting of two arms (lift arm 21 and compression arm 22), is pivotally supported on each of the pair of left and right mounting members 53. The base end of the upper lift arm 21 is pivoted by pivot 21a, and the base end of the lower compression arm 22 is pivoted by pivot 22a. Both pivots 21a and 22a are located forward of the first connecting pipe 52. An arm connecting member (second connecting pipe) 8, whose longitudinal direction is the width of the vehicle, is installed between the pair of left and right compression arms 22. This pipe 8 ensures the desired left-right synchronization and durability. The tip of each arm 21, 22 is pivoted by pivots 21b and 22b to a connecting shaft support member (connecting member) 6, which is made up of three plates welded together.

The base end of the loading platform 3 is rotatably supported on the lower end of the connecting member 6. The loading platform 3 is raised and lowered while maintaining the horizontal position shown in the figure using a parallel link mechanism consisting of the mounting member 53, lift arm 21, compression arm 22, and connecting member 6. The parallel link mechanism is driven by the extension and contraction of the hydraulic cylinder 7 attached to the mounting member 53.

Therefore, between the pair of left and right pivot arms 2 located at both the left and right ends of the vehicle width, excluding the loading platform 3, the first pipe 52 and the second pipe 8 are arranged in the lower area of the loading platform 1 across the vehicle width. Meanwhile, between the left and right mounting members 53, no components are arranged across the vehicle width, such as in the front position (area where the pivots 21a, 22a are provided).

Next, the configuration of the parallel link mechanism and the arrangement of the hydraulic cylinder 7 will be explained in detail using Figure 2. Figure 2 shows the state in which the receiving platform 3 has been manually raised after reaching the platform height position. The raised receiving platform 3 is secured by a rotating lever 3a located on the side of the receiving platform 3 and an engaging piece 1b located on the side gate 1a.

The hydraulic cylinders 7 attached to the mounting members 53 are arranged between two mounting members 53, with the barrel side 7a of the hydraulic cylinder 7 journaled to the mounting members 53 and the rod side 7b journaled to the operating arm 23. The operating arm 23 is integral with the lift arm 21, with one end journaled to the rod side 7b of the hydraulic cylinder 7 and the other end journaled to a pivot 21a that pivots the base end of the lift arm 21. The pivots 21a, 22a at the base ends of the lift arm 21 and compression arm 22 are aligned approximately vertically, and the pivots 21b, 22b at the tip ends are also aligned approximately vertically. The compression arm 22 is also aligned inward relative to the lift arm 21 in the vehicle width direction. As shown in the figure, when the loading platform 3 reaches floor height, the arms 21, 22 are configured so that the overlapping area between them is approximately maximized when viewed from the side. The ends of both arms refer to the ends closest to the loading platform 1 in the illustrated state.

The operation of the parallel link mechanism will now be explained using Figure 3. In Figure 3, the state in which the loading platform 3 has risen to the floor level of the loading platform 1 is shown by a solid line, and the state in which the loading platform 3 is mid-rising is shown by a dashed line.

The hydraulic cylinder 7 is fully extended when the loading platform 3 is at floor height. In other words, when the loading platform 3 is in its lowest position (on the ground), the hydraulic cylinder 7 is fully contracted, and when the hydraulic cylinder 7 extends, the operating arm 23 rotates counterclockwise. As the operating arm 23 rotates, the lift arm 21 and compression arm 22, which make up the parallel link mechanism, also rotate.

As shown in the figure, the compression arm 22 rotates upward to approach the lift arm 21. When the loading platform 3 is in its uppermost position, at floor height, the second connecting pipe 8 that connects and supports the left and right compression arms 22 is aligned in a substantially vertical line with the pivots 21b, 22b (connecting member 6). At this time, the loading surface of the loading platform 3 is continuous and substantially flush with the floor surface of the loading platform 1.

The loading platform lifting device 100 according to this embodiment is mounted in the limited space below the loading platform 1 and performs the above-described operations. Therefore, the mounting position of the loading platform lifting device 100 according to this embodiment relative to the vehicle will be specifically explained using Figure 4.

The lower rear area of the cargo bed 1 is provided with a muffler M1 that is fixed to the body frame 4 and discharges exhaust gases, and a tail lamp R1 that is fixed to the mounting member 53 via an upright mounting stay 401. In this embodiment, the muffler M1 occupies a large area below the cargo bed 1 in the fore-and-aft direction of the vehicle. Although not shown, a spare tire is fixed in the space S1 between the muffler M1 and the body frame 4.

The support portion 5 is located in an area surrounded by the space S1 where the muffler M1, tail lamp R1, and spare tire are located, as viewed from the side of the vehicle. Specifically, the first connecting pipe 52 is located vertically above the piping M11 of the muffler M1 by a distance H1. In other words, rather than being arranged side by side as in conventional configurations, the second connecting pipe is positioned so that it overlaps with the muffler M1 in the fore-and-aft direction of the vehicle when viewed from the side of the vehicle, but the muffler M1 is sandwiched between the front positions of the left and right mounting members 53 (see Figures 1 and 2). The second connecting pipe is located higher than the muffler M1, spanning the width of the vehicle and occupying a large area below the loading platform 1, thereby increasing the ground clearance of the loading platform lifting device 100.

The loading platform lifting device 100 according to this embodiment and a vehicle equipped with the device 100 are manufactured primarily as follows.

First, a bed mounting step is performed in which the bed 1 is mounted on top of the pair of left and right body frames 4, and a body frame accessory mounting step is performed in which the muffler M1 is mounted to the body frame 4 in the area below the bed 1. Both steps are known procedures and are often already completed when the vehicle is delivered to the body manufacturer's factory. It does not matter which step is performed first. The body frame accessory mounting step may also include the work of mounting the tail lamp R1 at the position that will become the rear end of the vehicle.

Next, after the loading platform mounting step and the body frame equipment mounting step, there is a lifting device mounting step for mounting the loading platform lifting device 100 to the body frame 4, which is carried out in the body manufacturer's factory. The lifting device mounting step includes a support part mounting sub-step for mounting the support part 5 to the body frame 4, a pivot arm mounting sub-step for mounting a pair of left and right pivot arms 2 that can rotate freely to the support part 5, and a loading platform mounting sub-step for supporting the tip of the pivot arm 2 on a connecting shaft support member (connecting member) 6 on which the loading platform 3 is supported.

In the support member installation substep, fixed support members (frame brackets) 51 are fixed to each of the pair of left and right body frames 4, and connecting support members (first connecting pipes) 52, whose longitudinal direction is the vehicle width direction, are fixed to the pair of left and right frame brackets 51 so that they are positioned higher than the muffler M1. The first connecting pipe 52 is fixed so that it is positioned vertically above the existing muffler M1 by a distance H1.

At this time (in the support portion attachment substep), the frame bracket 51 is fixed in a position where the muffler M1 and the support portion 5 overlap when viewed from the side of the vehicle. Specifically, the muffler M1 is included in the area that is the front position of the mounting support member (mounting member) 53. Also, in this embodiment, the tail lamp R1 is already attached to the rear end of the body frame 4 before the support portion attachment substep, but the tail lamp R1 may also be attached after the support portion 5 is installed. In either case, the support portion 5 can be installed appropriately in the area surrounded by the muffler M1, tail lamp R1, and space S1 where the spare tire is located, without interfering with each other.

In this embodiment, the configuration of the support portion 5 is cleverly utilized. The frame bracket 51, which is vertically attached below the body frame 4, ensures space for storing a spare tire near the underside of the body frame 4, near the center of the vehicle. Furthermore, by setting the height of the first connecting pipe 52 to which this frame bracket 51 is connected as described above, interference with the muffler M1, which occupies a large amount of space in the fore-and-aft direction below the cargo bed 1, can be avoided. Furthermore, since the first connecting pipe 52 is located lower than the tail lamp R1, interference can also be avoided. The first connecting pipe 52, which extends across the width of the vehicle, is located at the rear of the support portion 5, and a wide open area is secured across the width of the vehicle at the front of the support portion 5. This maximizes the relative positional relationship with the muffler M1, spare tire, and other components located further forward of the support portion 5.

Because the first connecting pipe 52, located at the rear, is close to the tail lamp R1, the compression arms 22 are also configured to prevent the second connecting pipe 8 from interfering with the lifting and lowering of the loading platform 3. The second connecting pipe 8, which is attached to the left and right compression arms 22, can be raised and lowered around the pivot 22a in the direction of arrow A1. The pivot 22a is offset forward from the first connecting pipe 52, thereby allowing for sufficient arm length. Because the tail lamp R1 must ensure a useful illumination range and angle, it is mounted nearly at the rear end of the vehicle as shown in the figure to avoid obstruction of the illuminated light. Even in this position, the compression arms 22 are long enough to avoid interference with the second connecting pipe 8. Furthermore, when the loading platform 3 reaches the floor level of the loading platform 1, it is close to the floor level of the loading platform 1 without any gaps, so that the pivots 21b, 22b and the second connecting pipe 8 can be positioned vertically in line, specifically, approximately vertically above the tail lamp R1.

The loading platform lifting device 100 according to this embodiment is therefore configured to increase ground clearance in the area below the loading platform 1, utilize the free space in the front-to-rear direction, maximize the illumination performance of the tail lamp R1, and further ensure that the floor of the loading platform 1 and the loading platform 3 are approximately flush with each other through stable rotation of the loading platform 3.

In addition, in this embodiment, the first connecting pipe 52 is located above the piping M11 of the muffler M1. To prevent the tail lamp R1 and other equipment from becoming too hot due to exhaust gases, the piping M11 of the muffler M1 is angled downward toward its tip, discharging exhaust gases downward toward the rear of the vehicle. By locating the first connecting pipe 52 in the space created by the downward slope of the piping (at vertical height H1), a margin of interference with the muffler M1 is increased. Note that, although the first connecting pipe 52 is located near the exhaust port of the piping M11 in this embodiment, it may also be located closer to the front of the vehicle or further forward of the piping M11.

As described above, the configuration and manufacturing method of this embodiment are extremely effective for bodybuilders who perform the lifting device installation step after the bed mounting step and body frame equipment mounting step. While the enclosed area described above is already a limited area at the start of the lifting device installation step, the open area at the front of the support part 5 can be used as an overlap area with the muffler M1, and the first connecting pipe 52 can be positioned above the muffler M1 to ensure sufficient ground clearance. This configuration and manufacturing method also allows for a more compact installation space for the bed lifting device 100, making it particularly useful for low-floor vehicles where the height from the ground to the bed is limited.

Furthermore, the loading platform lifting device 100 according to this embodiment may be configured not only as shown in FIG. 4(a) but also as shown in FIG. 4(b), in a position that does not overlap with the muffler M101 when viewed from the side of the vehicle, that is, a position that is rearward of the muffler M101 but at a height that is vertically higher than the muffler M101. By positioning the loading platform lifting device 100 at such a height, the ground clearance of the loading platform lifting device 100 can be increased compared to conventional configurations in which the device is mounted at the same height as the muffler M101. This also helps to ensure that the loading platform lifting device 100 is mounted on the vehicle in a way that effectively utilizes space for future new electrified devices and the like.

The present invention is not limited to the above-described embodiment, but can be applied to any platform lifting device that has a support portion with its longitudinal direction aligned with the vehicle width, such as the first connecting pipe 52, and any vehicle equipped with such a platform lifting device.

The present invention is useful for a platform lifting device having a parallel link mechanism.

1 Loading platform 2 Rotating arm 3 Load receiving platform 4 Body frame 5 Support portion 6 Connecting member (connecting shaft support member)
7 Hydraulic cylinder 8 Second connecting pipe (arm connecting member)
21 Lift arm (upper arm)
22 Compression arm (lower arm)
41 Main frame 42 Subframe 51 Frame bracket (fixed support member)
52 First connecting pipe (connection support member)
53 Mounting member (mounting support member)
M1 muffler (gas exhaust device)
M11 Piping (gas exhaust device)
R1 tail lamp

Claims (4)

a pair of left and right fixed support members fixed to a pair of left and right body frames, each of which has a longitudinal direction in the front-rear direction of the vehicle, below the loading platform of the vehicle;
a connecting support member having a longitudinal direction in the vehicle width direction that connects the pair of left and right fixed support members;
Mounting support members attached to left and right end portions of the connecting support member, respectively;
a pair of left and right pivot arms whose base ends are pivotally connected to the mounting support members, respectively;
a connecting shaft support member on which the tip ends of the rotating arms are supported;
a load receiving platform supported by the connecting shaft support member,
Each of the pair of left and right rotating arms has an upper arm and a lower arm,
an arm connecting member having a longitudinal direction in the vehicle width direction that connects the lower arms together is provided;
A loading platform lifting device characterized in that the mounting support member is positioned at a height that overlaps with the piping of a muffler that has a main body attached under the loading platform of the vehicle and a piping extending from the main body toward the rear of the vehicle and that is thinner than the main body, and the connecting support member is positioned at a position that is more rearward of the vehicle than the main body of the muffler attached under the loading platform of the vehicle and higher than the piping, and is mounted on the rear of the vehicle so as to avoid interference with the muffler. The loading platform lifting device described in claim 1, characterized in that the arm connecting member is rotated in conjunction with the lifting and lowering operation of the loading platform in a state that can avoid a tail lamp fixed to the rear of the vehicle, and is positioned approximately vertically below the connecting shaft support member when the loading platform is approximately flush with the loading platform. a loading platform provided on the body frame;
a muffler provided below the loading platform;
a tail lamp fixed to a rear portion of the body frame;
3. A vehicle equipped with the loading platform lifting device according to claim 1 . a loading platform mounting step of mounting a loading platform on a pair of left and right body frames with the longitudinal direction of the vehicle being the fore-and-aft direction; a body frame equipment mounting step of mounting a muffler to the body frame in an area below the loading platform; and a lifting device mounting step of mounting a loading platform lifting device on the body frame after the loading platform mounting step and the body frame equipment mounting step.
A method for manufacturing a vehicle equipped with the loading platform lifting device, comprising:
The lifting device mounting step includes:
a support portion attaching substep of attaching a support portion to the body frame in an area below the loading platform;
a pivot arm mounting substep of mounting a pair of left and right pivot arms rotatably to the support portion;
a load receiving platform mounting sub-step for pivotally supporting the tip end of the pivot arm on a connecting pivot support member on which the load receiving platform is supported,
The support portion includes a fixed support member, an attachment support member, and a connecting support member;
a mounting support member for mounting the muffler to the vehicle body frame; a connecting support member for connecting the muffler to the mounting support member; a connecting support member for connecting the muffler to the vehicle body frame; a connecting support member for connecting the muffler to the mounting support member; a connecting support member for connecting the muffler to the mounting support member; a connecting support member for connecting the muffler to the mounting support member;