JPH057290Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is an automatic paving work vehicle such as an asphalt finisher that can save labor by reducing the number of people involved in driving and paving work. It relates to a steering device.

[Prior Art] As is well known, in an asphalt finisher, while a traveling vehicle is running, asphalt mixture (paving material) introduced into a hopper provided on the traveling vehicle is fed to a rear screw by a pair of left and right feeders. At this point, it is spread evenly from side to side and then spread evenly with a screed. in this case,
Normally, a dump truck for replenishing mixed wood is placed in front of the moving vehicle, and while listening to the hoppers of the moving vehicle to the left and right, the dump truck's loading platform is tilted and the material is supplied to the hopper while paving work is being carried out. That's what I do.

[Problems that the invention attempts to solve] By the way, in conventional asphalt finishing, the operator who operates the machine
Two workers were required: a screed operator and an operator (screed man) to operate the screed, but there were complaints that it was labor-intensive and uneconomical. For this reason, it is desired to automate various tasks associated with road paving so that one worker can perform all operations of an asphalt finisher (one-man operation). In particular, if the driving operation can be automated, workers can concentrate on finishing the paved surface, resulting in high-quality paving. Automatic steering devices used for this purpose include those that follow the planned driving course using laser light sensors, optical sensors, etc., and those that memorize the course in a computer, but these devices are not installed in the vehicle. It requires preparation not only for the equipment to handle the vehicle, but also for the running course, making it complicated to handle. Additionally, the device itself is expensive, making it difficult to put it into practical use.

[Means for Solving the Problems] In order to solve the above-mentioned problems, this invention is led by a dump truck that replenishes paving material, and stores it in the hopper of the traveling vehicle while the vehicle is running. In a paving work vehicle that performs paving work by sending paving material to a leveling device, a pair of contactors that contact the left and right rear wheels of a dump truck are provided at the front of the vehicle. This system is equipped with a control device that steers the traveling vehicle by detecting the presence or absence of contact. The contact element is one that detects the pressure caused by contact, or
The rotation of the rear wheels is transmitted through contact, and a device that detects this rotation is adopted.

[Function] In such a paving vehicle, when both the left and right contacts are in contact, the control device outputs a signal that causes the traveling vehicle to go straight, and when one of the contacts leaves, it outputs a signal that causes the vehicle to go straight. Outputs a signal to steer the vehicle to the opposite side. As a result, the paving vehicle follows the leading vehicle, such as a dump truck, which is in front of it.

[Embodiment] An embodiment of this invention will be described below with reference to the drawings.

In Figures 1 to 6, reference numeral 1 denotes an asphalt finisher AF running vehicle, and this running vehicle 1 rotates a drive wheel 2 by an engine (not shown) mounted inside the drive wheel 2. The vehicle travels by rotating a crawler 4 wound around a driving wheel 3. This asphalt finish
The AF is equipped with a hopper 6 at the front that has a lid 5 that can be opened and closed to the left and right. The material is then spread out to the width of the pavement, and then spread evenly with a screed 8.

As shown in FIG. 3, the running drive mechanism of this running vehicle 1 includes a gearbox 9 that receives rotational output from a drive source (not shown) such as a hydraulic motor, and a gearbox 9 installed at the left and right ends of an output shaft 10 of this gearbox 9. left and right clutches 11, 12 which transmit the rotation of the output shaft 10 to the drive wheels 2 in a manner that allows them to move toward and away from each other; and hydraulic cylinders 13, 14 which open and close the clutches 11, 12.
and pressurized oil from the hydraulic source 15 to the hydraulic cylinder 1.
A solenoid valve 1 that is supplied to terminals 3 and 14 to operate the clutches 11 and 12 in the connecting or disengaging direction.
6,17.

At the front end of the traveling vehicle 1, a pair of left and right push rollers (contactors) 19 and 20 are supported rotatably within a vertical plane by a pair of arms 21, respectively, at positions in contact with the rear wheels 18 of the dump truck DT. Rotary encoders 23 and 24 are attached to the rotating shafts 22 of these push rollers 19 and 20, so that their rotation can be detected. And this rotary encoder 23,2
The detection output of No. 4 is input to the control device 25, and the control device 25 judges the signal and sends an opening/closing control signal to the left and right solenoid valves 16 and 17.

Below, the operation of the automatic steering system of this paving work vehicle will be described in the fourth section showing the signal processing process in the control device.
This will be explained with reference to the flowchart shown in the figure, and FIGS. 5 and 6.

During manual operation, the traveling vehicle 1 keeps its front end in close contact with the dump truck DT, as shown in FIG. After making it possible and setting the traveling speed etc.
Switch the changeover switch (not shown) on the operator's seat to automatic operation.

This causes the control device 25 to operate, but in this control device 25, taking into account the instability of the contact between the rear wheels 18 of the dump truck DT and the push rollers (hereinafter abbreviated as rollers) 19, 20,
The vehicle 1 is set to be steered only when only one of the rollers 19, 20 does not rotate for a certain period of time or more. i.e. st (step)
In step 1, it is determined whether the left roller 19 is rotating, and if the left roller 19 is rotating, it is further determined whether the right roller 20 is rotating (st2), and the right roller 2 is rotated.
If 0 is also rotating, continue straight ahead without steering. This state continues when the dump truck DT moves straight as shown in FIG. When the dump truck DT is steered to the left as shown in FIG. 6, the right roller 20 separates from the rear wheel 18 of the dump truck, and the stoppage of rotation of the right roller 20 is detected at st2. Then, in st4, the time during which the left roller 19 continuously rotates is measured, and when this measured time Hl exceeds a certain reference time Ho,
The traveling vehicle 1 is steered to the left (st5). That is, a switching signal is output to the left solenoid valve 16, and from the state shown in FIG. 3, the pump side of the hydraulic power source 15 is communicated with the rod side of the left hydraulic cylinder 13, and the left clutch 11 is disconnected. Then, since only the right crawler 4 rotates, the traveling vehicle 1 is steered to the left, and soon the right roller 20 moves to the dump truck DT.
the rear wheel 18 of the vehicle. And yes in st2
Then, the left steering state is released, the left clutch 11 is reconnected, and the traveling vehicle 1 gradually returns to the straight-ahead state. This process is carried out by the dump truck DT.
This is a process in which the traveling vehicle 1 follows the steering direction with a certain delay, but by appropriately adjusting the above reference time Ho, the traveling vehicle 1 will also be delayed when the dump truck DT returns to going straight. It is possible to recover this and make the vehicle go straight. Furthermore, when the dump truck DT is steered to the right, the traveling vehicle 1 is steered to the right through the steps st1→st6→st7→st8→st9 in the control device 25 in substantially the same way. Furthermore, during a series of steps, the switching position of the changeover switch on the operation panel of the traveling vehicle 1 is determined (st10), and if this is on the manual side,
Autonomous driving is being shut down.

Such a steering device normally uses a dump truck DT, which is required for replenishing paving mixture, as a lead vehicle for automatic steering, and does not require complicated and expensive equipment. It is also easy to operate since there is no need to install guide members along the course in advance.

In addition, in the above, the push roller 19,
Although only the steering is performed by detecting the rotation of the push rollers 19 and 20, for example, the rotation speed of the push rollers 19 and 20 may be detected to control the traveling speed of the traveling vehicle 1. Push roller 1 in case the engine stalls.
An emergency stop device may be provided to stop the traveling vehicle 1 when a load of a certain level or more is applied to the axes 9 and 20. Furthermore, instead of a rotation detector, a pressure sensor may be provided to directly detect the contact pressure.

FIG. 7 shows another embodiment of this invention, in which the traveling drive mechanism does not employ crawlers 4 as in FIGS. 1 and 3, but instead uses wheels (tires).
was adopted. That is, the front wheels 26,2
Reference numeral 7 designates a steering wheel, and a crank member 29 rotatable in a substantially horizontal plane is supported by shaft pins 28 provided on the left and right sides of the lower part of the traveling vehicle 1, and a wheel 26, 27 is pivotally supported, and the other ends of both crank members 29 are connected to the connecting member 3.
0, and the left and right wheels 26, 27 are interlocked by a connecting member 30. This connecting member 30 is connected to the solenoid valve 3.
A pair of hydraulic cylinders 33 facing each other, to which pressure oil is switched and supplied from a hydraulic source 32 by 1.
34, and the solenoid valves 31,
By switching the number 32, the vehicle can be steered left and right. Although the traveling drive mechanism is different in this embodiment, the device configuration shown in FIG.
The programs of the control devices shown in the figures are basically the same, and the operations and effects are also almost the same.

[Effects of the invention] As detailed above, this invention is led by a dump truck that replenishes paving material, and while the vehicle is running, the paving material stored in the hopper of the vehicle is transferred to the leveling device. In a paving work vehicle that carries out paving work, a pair of contactors that contact the left and right rear wheels of the dump truck are installed at the front of the vehicle, and the presence or absence of contact with these contactors is detected to control the speed of the vehicle. Since it is equipped with a control device to steer the
This system enables automatic steering of the paving vehicle, contributing to labor savings, and allows workers to concentrate on inspecting the paving section, resulting in high-quality paving.

[Brief explanation of the drawing]

Fig. 1 is an overall view of an asphalt finisher according to an embodiment of this invention, Fig. 2 is a block diagram showing the configuration of the control system, Fig. 3 is a diagram showing the travel drive mechanism, and Fig. 4 is a diagram of the control system. FIG. 5 is a flowchart showing the logic, FIG. 5 is a diagram showing the connection between the asphalt finisher and the dump truck, FIG. 6 is a plan view, and FIG. 7 is a diagram showing the traveling drive mechanism of another embodiment of this invention. be. AF……Asphalt finish, DT……
Dump truck, 1... Traveling vehicle, 6... Hopper, 18... Rear wheel, 19, 20... Push roller (contact element), 25... Control device.

Claims (1)

[Scope of utility model registration request] In a paving work vehicle that is guided by a dump truck that replenishes paving materials and performs paving work by moving the vehicle and sending the paving material stored in the hopper of the vehicle to a leveling device, a vehicle in front of the vehicle. The part is provided with a pair of contacts that contact the left and right rear wheels of the dump truck, and is also provided with a control device that steers the traveling vehicle by detecting the presence or absence of contact with the contacts. Automatic steering device for paving work vehicles.