JPH05468Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a heavy truck for transporting large and extremely heavy members, such as bridge girders, mainly during the construction of bridges.

When transporting long steel materials such as bridge girders, P/S concrete, etc. weighing around 150 tons to the bridge construction site, normally self-propelled trolleys are used on pre-laid tracks, as shown in Figure 1. After the cargo (d) was loaded across the trolley and the auxiliary trolley (c) arranged at a necessary distance, it was pushed or towed by a power trolley equipped with a separate generator (e).

Therefore, when this type of heavy truck for extremely heavy objects is operated with an actual vehicle loaded with objects to be transported, it is necessary to operate at an extremely low speed to prevent derailment and collapse of the cargo.
On the return trip when the truck is empty, it is important to run the truck as fast as possible and to keep the total height H of the truck as low as possible in order to improve work safety and efficiency.

However, in the conventional technology, as a speed switching means for the above-mentioned self-propelled trolley B, for example, the rotation of a constant output electric motor is changed by operating a transmission gear and its clutch, or two electric motors having different speeds are connected to each axle. Since the gears were connected to each other and could be selected alternately, they not only had complicated structures and required particular effort to change gears, but also
Due to its structure, the total height H of the cart increases, which not only reduces the efficiency of loading and unloading objects, but also increases the accident rate.

In view of these circumstances, the present invention is a heavy-duty truck consisting of a power truck equipped with a generator, a self-propelled truck driven by an electric motor, and an auxiliary truck. By attaching a single electric motor and changing the number of poles of the electric motor, the rotational speed of the wheels of the self-propelled cart can be changed depending on the presence or absence of objects to be transported.

Hereinafter, the configuration of the self-propelled trolley according to the present invention will be described in more detail according to the embodiment shown in the drawings. 1 is an underframe; 2;
Reference numeral 2' denotes a variable-pole electric motor installed at the front and rear of the underframe, which is usually composed of 4 to 12 poles, and rotates in a variable speed manner by receiving electric power from the generator H on the power truck. It's something you get.

Furthermore, numerals 3 and 3' indicate front and rear axles to which wheels 4 are fixed at both ends, and each is driven by, for example, a chain system 5 via the electric motors 2 and 2'.

In the figure, 6 indicates a connecting bracket, and 7 indicates a connecting rod thereof.

In the present heavy-duty truck having the above configuration, the drive mechanism of the self-propelled truck consists of two pole change type electric motors 2 and 2' that operate in synchronization with each other, and by changing the pole number of each motor, For example, set the traveling speed of the trolley to 5m/
Since it can be adjusted freely within the range of mm to 25m/mm, in actual use, the object to be transported is straddled over the self-propelled trolley RO and the auxiliary trolley C, which are placed at an appropriate distance in advance. After mounting the vehicle on top of the bridge and connecting the power truck to the above-mentioned self-propelled truck, turn on the low-speed operation switch on the power truck to start the vehicle, and when it arrives at the bridge construction site, stop it by operating the switch and transport it from the truck. It's about unloading things.

When unloading is completed in this way, by turning on the high-speed operation switch, both electric motors rotate in reverse, and at the same time, the number of poles is changed to a preset value, and the vehicle travels at high speed to its original position.

As described above, the present invention provides a heavy-duty truck consisting of a power truck equipped with a generator, a self-propelled truck driven by an electric motor, and an auxiliary truck. By attaching one motor and changing the number of poles of the electric motor, the rotational speed of the wheels of the self-propelled cart can be changed depending on the presence or absence of objects to be transported. Therefore, there is no need to provide a separate transmission gear or clutch mechanism as a speed switching means, or to selectively drive one axle with two types of electric motors having different rotational speeds, as in the prior art. Therefore,
Not only is it easy to change the speed of the truck, the structure of the self-propelled truck is extremely simplified, and at the same time, the loading surface of the truck can be lowered by about 10 to 20 cm at once. It has various excellent practical advantages, such as being able to carry heavy objects safely and making it easier to load and unload cargo.

[Brief explanation of the drawing]

FIG. 1 is a side view of a heavy truck loaded with objects to be transported, FIG. 2 is a plan view of a self-propelled truck in the proposed heavy truck, and FIG. 3 is a side view thereof. In the figure, 1...underframe, 2, 2'...pole convertible electric motor, 3, 3'...axle, 4...wheels.

Claims (1)

[Scope of utility model registration request] In a heavy truck consisting of a power truck equipped with a generator, a self-propelled truck driven by an electric motor, and an auxiliary truck, one pole-changeable electric motor is installed before and after the underframe of the self-propelled truck, and the motor A heavy truck characterized in that the rotational speed of the wheels of the self-propelled truck can be changed by changing the number of poles depending on the presence or absence of an object to be transported.