JP2017094859A - Dump truck for mine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dump truck for a mine capable of suppressing occurrence of pullout, and preventing decline of work efficiency in a mine.SOLUTION: In a control part of a dump truck for a mine, when the attitude of a load-carrying platform (3) reaches a third inclination threshold (θ1), it is determined whether a load balance is equal to or greater than a first load threshold (W1) or not, and when determined that the load balance is equal to or greater than the first load threshold, actuation of a hoist cylinder (4) is controlled so that the load-carrying platform is rotated until the attitude of the load-carrying platform reaches a second inclination threshold (θ2) and then stopped.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a mine dump truck, and more particularly to a technique for suppressing pull-out that occurs when a load is released.

  In a large dump truck used in a mine, the weight of a load such as an ore loaded on the loading platform is large, so the impact on the vehicle during unloading work (unloading work) is large and cannot be ignored. In particular, when ore falls from the loading platform during unloading work, a hoist cylinder that moves the loading platform up and down causes a so-called pull-out. This is important for trucks.

  For example, Patent Document 1 is known as a technique that can perform an unloading operation safely while suppressing an impact applied to a vehicle even if the gravity of a load is large. Patent Document 1 states that “in a dump truck having a hydraulic circuit that tilts a vessel by a cylinder mechanism, the vessel is temporarily stopped when the angle reaches an optimum angle for discharging the load, and then the vessel is allowed to pass for a certain period of time. In addition, a means for detecting the inclination angle of the vessel is provided, and the inclination speed by the cylinder mechanism is reduced before the vessel stops according to the detection angle by the means. "(See summary).

JP 05-139200 A JP 2007-298449 A JP 2010-190617 A

  In Patent Document 1, it is configured to temporarily stop when the vessel (loading platform) has an optimum angle for unloading the load, but in a dump truck for mining, it is optimal for unloading work (dump work) The angle of the load carrier (hereinafter referred to as “body” as appropriate) is near the maximum body tilt angle at which the lift angle of the load bed is maximized. Therefore, in Patent Document 1, the optimum load carrier angle is set near the maximum body tilt angle. Are still prone to pull-out.

  On the other hand, when the load is small, even if the loading platform is raised to the maximum body tilt angle and unloaded at a stretch, there is little impact on the vehicle, so from the viewpoint of work efficiency, the loading platform is not temporarily stopped in the middle of unloading Is preferable. However, Patent Document 1 has a configuration in which the loading platform is temporarily stopped at an optimum loading platform angle for unloading work, and thus there is a problem that work efficiency is reduced when the loading amount of the loading platform is small.

  As described above, in the technique described in Patent Document 1, there is room for improvement in suppressing the occurrence of pull-out in the mine dump truck and preventing the reduction in work efficiency.

  This invention is made | formed in view of the above-mentioned actual condition, The objective is to provide the dump truck for mines which can suppress generation | occurrence | production of a pullout and can prevent the fall of the working efficiency in a mine.

  In order to achieve the above object, a representative present invention includes a vehicle body frame, front and rear wheels respectively attached to the vehicle body frame via a suspension, a prime mover for driving the front wheel or the rear wheel, and the vehicle body. A loading platform attached to the frame via a hinge pin, a hoist cylinder that rotates the loading platform in the vertical direction around the hinge pin, a pressure sensor that detects the pressure of each suspension, and at least the operation of the prime mover and the hoist cylinder A control unit for controlling the vehicle, and a dump truck for mining provided with a posture detection sensor for detecting a posture of the loading platform with respect to the vehicle body frame, and the control unit is configured based on pressure data from the pressure sensors. Calculates the load balance of the mining dump truck, and the load balance The operation of the hoist cylinder is controlled based on the attitude of the loading platform detected by the attitude detection sensor, and a first load threshold (W1) is preset as a threshold for the load balance, and the attitude of the loading platform As a threshold for the first inclination threshold (θ3) at which the inclination angle of the loading platform becomes maximum, a second inclination threshold (θ2) having an inclination angle smaller than the first inclination threshold, and the second inclination threshold A third inclination threshold value (θ1) having a small inclination angle is set in advance, and the control unit determines that the load balance is greater than or equal to the first load threshold value when the attitude of the loading platform reaches the third inclination threshold value. And when the load balance is determined to be equal to or greater than the first load threshold value, after rotating the load platform until the load platform posture reaches the second inclination threshold value. stop And controlling the operation of the hoist cylinder to.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of a pullout can be suppressed and the dump truck for mines which can prevent the fall of the working efficiency in a mine can be provided. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

The side view of the dump truck for mines which concerns on embodiment of this invention. The figure which shows the rotation position of a loading platform. The block diagram of the input-output to a control apparatus. The block diagram of the input / output of pressure oil to the hoist cylinder. The flowchart which shows the procedure of the control processing which suppresses pullout generation | occurrence | production. The flowchart which shows the procedure of the control processing which suppresses pullout generation | occurrence | production.

  A mine dump truck according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a mining dump truck according to an embodiment of the present invention. As shown in FIG. 1, a dump truck for mining according to this embodiment (hereinafter abbreviated as a dump truck) includes a vehicle body frame 1, a cab 2 provided at the front of the vehicle body frame 1, and a vehicle body frame 1. The loading platform 3 is held in a vertical direction between a solid line and a two-dot chain line via a loading platform (body) 3 on which a load such as ore is loaded and a hinge pin 21 attached to the rear portion of the vehicle body frame 1. The hoist cylinder 4, the left and right suspension cylinders 5a disposed on the left and right front wheels 20a, the left and right suspension cylinders 5b disposed on the left and right rear wheels 20b, and an engine 25 that drives the rear wheels 20b as driving wheels (see FIG. 1) (not shown in FIG. 1).

  An angle sensor 22 for detecting the rotation angle of the loading platform 3 is provided in the vicinity of the hinge pin 21, and the rotation angle of the loading platform 3 relative to the vehicle body frame 1 based on the detection signal from the angle sensor 22. (Posture) can be detected. If the stroke position (extension distance) of the hoist cylinder 4 is known, the rotation angle of the loading platform 3 with respect to the vehicle body frame 1 can be obtained. Therefore, the stroke sensor detects the stroke position of the hoist cylinder 4 instead of the angle sensor 22. (Not shown) may be used. Both the angle sensor 22 and the stroke sensor correspond to the “attitude detection sensor” of the present invention.

  The front suspension cylinder 5 a and the rear suspension cylinder 5 b support the vehicle body frame 1, the loading platform 3, and a load (heavy load) loaded on the loading platform 3. Pressure sensors 10a and 10b for measuring cylinder pressure are attached to the suspension cylinders 5a and 5b, respectively. The load of the load is measured based on the detection data from the pressure sensors 10a and 10b.

  In addition, an inclination sensor 11 for detecting the inclination of the vehicle body frame 1 is attached to the cab 2, and a lifting operation (body raising operation) and a lowering operation (body lowering operation) of the cargo bed 3 are performed. An operation lever (not shown) and various display devices (not shown) are also provided. In addition, if it is a flat work site, the inclination sensor 11 may not be provided.

  FIG. 2 is a diagram illustrating the rotation position (tilt angle) of the loading platform 3. In FIG. 2, three stages are shown as the rotation position of the loading platform 3. The inclination angles θ1, θ2, and θ3 of the respective loading platforms 3 serving as the three rotation positions are set in advance as inclination thresholds when determining the occurrence of pull-out. Specifically, the position where the loading platform 3 is rotated upward to the body inclination angle θ3 (the angle indicated by reference numeral 6) is the maximum rotation position in the lifting direction of the loading platform 3, that is, the maximum body lifting position. The body inclination angle θ3 at which the loading platform 3 is inclined to the maximum body raising position is the first inclination threshold value of the present invention.

  Needless to say, the position where the hoist cylinder 4 extends to the maximum body raising position is the maximum extension position of the hoist cylinder 4. Here, the hoist cylinder 4 is configured such that even if the loading platform 3 rotates to the maximum body position, the hoist cylinder 4 can be allowed to extend somewhat. Therefore, the loading platform 3 may be in a posture rotated to a slightly larger angle than the body tilt angle θ3 (when the tilt angle θ of the loading platform 3 exceeds θ3, that is, Yes in S9 of FIG. 5). ).

  The tilt angle at which the loading platform 3 rotates to the position 8, that is, the body tilt angle θ2 slightly smaller than the body tilt angle θ3 is the second tilt threshold of the present invention, and the tilt angle at which the loading platform 3 rotates to the position 7. That is, the body inclination angle θ1 slightly smaller than the body inclination angle θ2 is the third inclination threshold value of the present invention. In addition, when calculating | requiring the inclination-angle of the loading platform 3 from the stroke position of the hoist cylinder 4, what is necessary is just to set the stroke position of the hoist cylinder 4 as a 1st-3rd inclination threshold value.

  Next, details of control for suppressing the occurrence of pull-out will be described. FIG. 3 is a diagram showing a configuration of input / output to the control device 9, and FIG. 4 is a diagram showing a configuration of input / output of pressure oil to the hoist cylinder 4. The control device (control unit) 9 includes a calculation unit that performs axial load calculation, and as shown in FIG. 3, detection signals from the pressure sensors 10a for detecting the cylinder pressure of the left and right suspension cylinders 5a on the front side, A detection signal from each pressure sensor 10b for detecting the cylinder pressure of the left and right suspension cylinders 5b on the rear side, a detection signal from the inclination sensor 11, and a detection signal from the angle sensor 22 are input. In this embodiment, the value of the rear axle weight W, which is the load applied to the rear axle that pivotally supports the rear wheel 20b, is used as the load balance, but the pressure difference between the suspension cylinders 5a and 5b is simply used. You may make it perform the pull-out prevention control demonstrated below.

  The control device 9 can convert the pressure data obtained from the pressure sensor 10a into a load applied to the suspension cylinder 5a by integrating the pressure data with the pressure receiving area of the suspension cylinder 5a. Similarly, by integrating the pressure data obtained from the pressure sensor 10b with the pressure receiving area of the suspension cylinder 5b, it can be converted into a load applied to the suspension cylinder 5b. And the control apparatus 9 calculates | requires the total load concerning suspension cylinder 5a, 5b by summing the load concerning each suspension cylinder 5a, 5b.

  The control device 9 corrects the tilt intersection using the tilt angle data from the tilt sensor 11 for the obtained total loads of the suspension cylinders 5a and 5b, and the suspension cylinders 5a and 5b when the vehicle body frame 1 is not tilted. Calculate the total suspension load for the suspension. Then, the control device 9 divides the eccentric loading correction value from the corrected suspension total load, performs the eccentric loading correction of the load, and calculates the loading load.

  The control device 9 calculates the front axle weight and the rear axle weight W of the entire vehicle body using the load ratio calculated by this calculation and the pressure ratio of the suspension cylinders 5a and 5b corrected when the vehicle body frame 1 is not inclined. To do. In the present embodiment, the rear axle weight W obtained as a result is used as a pull-out detection parameter of the hoist cylinder 4.

  Note that methods for calculating the front axle weight and the rear axle weight of the entire vehicle body are known in Patent Documents 2 to 3, and in this embodiment, these techniques are also used for computation. In the present specification, description regarding the calculation method is omitted.

  When the rear axle weight W is obtained, the control device 9 determines whether or not a predetermined threshold is exceeded as a pull-out occurrence condition using the rear axle weight W. If the rear axle weight W is exceeded, the proportional solenoid valve 12 is exceeded. Outputs an electrical signal to stop raising the body. When this body raising stop signal is received, the control valve 13 is operated via the proportional solenoid valve 12 and the hydraulic pressure supplied from the pump 14 to the hoist cylinder 4 is cut off, so that the body raising operation is stopped.

  Next, a control processing flow for suppressing the occurrence of pull-out will be described with reference to FIGS. 5 and 6. 5 and 6 are flowcharts showing the processing procedure of pull-out occurrence suppression control in this embodiment. As shown in FIG. 5, the control device 9 reads the operation by the operation lever after the operator starts the operation of the loading platform 3 (step S1). Next, when the operation of the loading platform 3 by the operation lever is a body raising operation, the control device 9 reads the body inclination angle θ and the rear axle weight W of the raised loading platform 3 (procedures S2, S3, S4). When the body inclination angle θ of the loading platform 3 reaches the body inclination angle θ1, the control device 9 determines whether or not the rear axle weight W is equal to or greater than a first load threshold value W1 defined as a pullout occurrence condition ( Procedure S5, S6).

  When the rear axle weight W is greater than or equal to the first load threshold W1, when the body tilt angle θ of the loading platform 3 reaches the body tilt angle θ2, the controller 9 applies a body raising stop command to the proportional solenoid valve 12 Then, the spool of the control valve 13 is moved via the proportional solenoid valve 12 to stop the body raising operation (procedures S7 and S8). Control for stopping the body raising operation is pull-out prevention control (S8).

  Here, when the body tilt angle θ of the loading platform 3 is less than the body tilt angle θ3 that is the maximum body lifting position, the control device 9 raises the body until the tilt angle θ of the loading platform 3 reaches the maximum body tilt angle θ3. The operation is accepted (steps S9 and S10). On the other hand, when the body tilt angle θ is equal to or greater than the maximum body tilt angle θ3, the body raising operation is immediately stopped by an output signal from the control device 9 (steps S9 and S11).

  When the rear axle weight W is less than the first load threshold W1 (procedure S6 / No), the pull-out prevention control is not executed, and the operator can perform the body raising operation up to the body inclination angle θ3. That is, when the rear axle weight W is less than the first load threshold value W1, it can be considered that pull-out does not occur. Therefore, the body raising operation is performed without performing the pull-out prevention control in step S8. This prevents a reduction in work efficiency when the rear axle weight W is less than W1. When the body tilt angle θ is equal to or greater than the body tilt angle θ3, the body raising operation is stopped by a normal process that does not perform the pull-out prevention control (steps S6, S9, S10, and S11).

  After the body raising stop in step S11, the control device 9 inquires the rear axle load W as the second load threshold value W2 determined as the pull-out occurrence condition. If the pull-out occurrence condition is not satisfied, all control of the pull-out prevention control is performed. End (procedure S12 / No). In step S12, when the rear axle weight W is equal to or greater than the second load threshold W2 (S12 / Yes), step S13 shown in FIG. 6 is executed. Here, in step S12, since the loading platform 3 is in a posture rotated by the body inclination angle θ3 or more, pull-out is likely to occur. Therefore, for the purpose of more safely controlling the operation of the dump truck, the second load threshold W2 is set to a value (W2 <W1) smaller than the first load threshold W1.

  Next, when the procedure proceeds to step S13, the body inclination angle θ becomes equal to or greater than the maximum body inclination angle θ3, and pullout is likely to occur. Therefore, the control device 9 controls the drive of the engine 25 to prohibit the start of the dump truck or restrict the start speed of the dump truck and prohibit the body raising operation beyond that and allow only the body lowering operation (procedure) S13, S14).

  When the body tilt angle θ is lowered to, for example, the vicinity of the body tilt angle θ1 by the body lowering operation, the control device 9 regards that the risk of pull-out has been eliminated and restricts the dump truck start or restricts the dump truck start speed. And the prohibition of the body raising operation is canceled (procedures S15 and S16). Thereafter, the control device 9 inquires the rear axle load W as the first load threshold value W1, and when the pull-out occurrence condition is satisfied (when W ≧ W1), the process proceeds to step S7 (see FIG. 5). On the other hand, when the pull-out occurrence condition is not satisfied (when W <W1), the control device 9 shifts the process to step S9 in FIG.

  As described above, according to the present embodiment, the rear axle weight W as the load balance is used as a parameter for detecting the pull-out occurrence, and the rear axle weight when the body tilt angle θ of the loading platform 3 is rotated to θ1. If W is less than W1 (S6 / No), it is controlled to skip the pull-out prevention control (S8), so that it is possible to prevent a reduction in work efficiency in a situation where pull-out is unlikely to occur. Also, by using the rear axle weight W as a parameter, when a highly viscous load is attached to the cargo bed 3 body when the body inclination angle θ reaches θ1 that is the third inclination threshold, the rear axle Since the load applied to the heavy load increases, it is possible to detect a state where pull-out is likely to occur. Then, when the body lifting operation is stopped when the body tilting angle θ reaches the second tilt threshold value θ2, the maximum body tilt angle θ3 is given a margin to the first body tilt angle θ3. When the vicinity of the angle is reached, it is possible to reduce the occurrence of pullout due to the load falling in a lump.

  Furthermore, when the dump truck starts in a situation where pullout is likely to occur and is close to the maximum body tilt angle, the body lifting operation is stopped and the maximum body tilt angle is reached when the body is lifted at the rotational position of the body tilt angle θ2. When the vicinity of θ3 is reached, the pull-out occurrence determination is performed again. When the condition is satisfied, the dump truck is prohibited from traveling, so that the possibility of pull-out due to inertial force can be reduced.

  Similarly, when the platform 3 is replaced with a product made by another company, it is possible to prevent the occurrence of pull-out due to the inertial force at the maximum body raising angle. Pulling out is reduced to allow the hoist cylinder 4 to be extended in a state where pullout is likely to occur, so that pulling out is reduced, and the impact to the hoist cylinder 4, loading platform 3, and body frame 1 due to the pullout occurrence. The frequency with which an excessive load is applied can be reduced. Further, by preventing pull-out, it is possible to prevent a decrease in ride comfort of the operator due to the occurrence of pull-out.

  In addition, embodiment mentioned above is an illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to those embodiment. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.

1 Body frame 2 Driver's cab 3 Cargo body
4 Hoist cylinder 5a Front suspension cylinder 5b Rear suspension cylinder 9 Control device (control unit)
10a Pressure sensor 10b Pressure sensor 11 Inclination sensor 20a Front wheel 20b Rear wheel 21 Hinge pin 22 Angle sensor (Attitude detection sensor)
25 engine (motor)
θ1 Body tilt angle (third tilt threshold)
θ2 Body tilt angle (second tilt threshold)
θ3 Body tilt angle (first tilt threshold)
W1 First load threshold W2 Second load threshold

Claims (5)

A vehicle body frame, front wheels and rear wheels attached to the vehicle body frame via suspensions, a prime mover driving the front wheels or the rear wheels, a cargo bed attached to the vehicle body frame via a hinge pin, and In a mining dump truck comprising a hoist cylinder that pivots vertically about a hinge pin, a pressure sensor that detects the pressure of each suspension, and a control unit that controls at least the operation of the prime mover and the hoist cylinder ,
An attitude detection sensor for detecting the attitude of the loading platform with respect to the vehicle body frame;
The control unit calculates a load balance of the mining dump truck based on pressure data from the pressure sensors, and based on the load balance and the attitude of the loading platform detected by the attitude detection sensor. Control the operation of the hoist cylinder,
A first load threshold value is preset as a threshold value for the load balance, and a first inclination threshold value at which the inclination angle of the cargo bed is maximized as a threshold value for the attitude of the cargo bed, the inclination angle from the first inclination threshold value A second inclination threshold value that is smaller than the second inclination threshold value, and a third inclination threshold value that is smaller than the second inclination threshold value.
The control unit determines whether the load balance is equal to or greater than the first load threshold when the posture of the loading platform reaches the third inclination threshold, and the load balance is determined by the first load threshold. When it is determined that the load is equal to or greater than a load threshold, the operation of the hoist cylinder is controlled so as to stop after the load platform is rotated until the posture of the load platform reaches the second inclination threshold value. Dump truck. In claim 1,
An inclination sensor for detecting an inclination angle of the body frame with respect to the ground;
The control unit corrects the load balance based on an inclination angle of the vehicle body frame detected by the inclination sensor, and controls the operation of the hoist cylinder using the corrected load balance. Dump truck for mining. In claim 1 or 2,
The control unit controls the operation of the hoist cylinder to stop after rotating the loading platform until the loading platform posture reaches the second inclination threshold, and then the loading platform posture is the first inclination. When it is determined that it is less than the threshold value, the operation of the hoist cylinder is controlled so as to stop after rotating the loading platform until the loading platform posture reaches the first inclination threshold value. Mine dump truck. In claim 3,
As a threshold for the load balance, a second load threshold smaller than the first load threshold is preset,
When the control unit determines that the load balance is greater than or equal to the second load threshold after the platform is rotated and stopped until the attitude of the cargo bed reaches the first inclination threshold, The mining dump truck is controlled so as to prohibit the extension operation of the hoist cylinder and restrict the driving of the prime mover. In claim 4,
When the control unit prohibits the hoist cylinder from extending and restricts the driving of the prime mover, and the attitude of the cargo bed becomes close to the third inclination threshold, the hoist cylinder A mining dump truck that performs control so as to cancel the prohibition of the extension operation and to cancel the restriction on driving of the prime mover.