JP2004268649A - Body lifting speed control device for dump truck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a body lifting speed control device for a dump truck capable of making a body lifting speed uniform at the time of switching a cylinder even when the cylinder which is of two-stage stroke type is used as a hydraulic cylinder. <P>SOLUTION: Speed coefficient pattern generating means 130, 140 of a controller 100 generates a speed pattern for controlling the lifting speed of a body so as to be uniform before and behind a switching point of a hydraulic cylinder 45 of the two-stage stroke type corresponding to a body angle detected by a body angle sensor 55. Each of multipliers 150, 155 multiplies an output signal of each of the speed coefficient pattern generating means 130, 140 by an operation signal of an operation lever 60 and outputs it to control the body lifting speed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a body lifting / lowering speed control device for a dump truck that controls the speed of lifting / lowering of a body, and more particularly to a dump truck suitable for automatically controlling the body lifting / lowering speed of a vehicle having a large loading weight such as a dump truck. The present invention relates to a truck body lifting speed control device.
[0002]
[Prior art]
In a conventional dump truck, for example, as described in Japanese Patent Application Laid-Open No. 2002-160574, raising and lowering of a body on which earth, sand, stones, and the like are loaded is performed by an operator of the dump truck raising or lowering an operation lever. The hydraulic cylinder that moves the body up and down is extended and contracted. When spouting earth and sand loaded on the body, the operator raises and operates the operation lever so that the spouting amount becomes constant.
[0003]
[Patent Document 1]
JP-A-2002-160574
[Problems to be solved by the invention]
Here, in a large dump truck, a two-stage stroke cylinder is used as the hydraulic cylinder because the stroke of the hydraulic cylinder for raising the body to the maximum angle becomes long. However, when a two-stage stroke cylinder is used as the hydraulic cylinder, since the bottom area of the first-stage cylinder and the bottom area of the second-stage cylinder are different, if the operation lever is operated while maintaining a constant angle, There is a problem that the amount of expansion and contraction differs before and after the switching point of the two-stage stroke cylinder, and the body elevating speed differs. In particular, there is a problem that the amount of spraying changes before and after the switching point of the two-stage stroke cylinder at the time of spraying.
[0005]
An object of the present invention is to provide a body lifting / lowering speed control device for a dump truck that can maintain the body lifting / lowering speed at the time of cylinder switching even when a two-stage stroke cylinder is used as a hydraulic cylinder.
[0006]
[Means for Solving the Problems]
(1) In order to achieve the above object, the present invention provides a body provided on a vehicle body, a hydraulic cylinder for elevating and lowering the body to a standing posture and a sitting posture, operating means, and an operating means. In a dump truck body lifting / lowering speed control device having a control means for controlling the lifting / lowering speed of a body by extending and retracting the hydraulic cylinder, the hydraulic cylinder is a two-stage stroke cylinder, and the control means The lifting speed of the body before and after the switching point of the stepped stroke cylinder is controlled to be constant.
In this way, the vertical movement speed of the body at the switching point of the two-stage stroke cylinder can be made constant.
[0007]
(2) In the above (1), preferably, there is provided a body angle detecting means for detecting an elevating angle of the body, and the control means is configured to control the two-stage stroke cylinder in accordance with the body angle detected by the body angle detecting means. Speed coefficient pattern generating means for generating a speed coefficient pattern such that the vertical movement speed of the body at the switching point is equal, and multiplying means for multiplying the operation signal of the operating means by an output signal of the speed coefficient pattern generating means It is provided with.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the configuration and operation of the body lifting / lowering speed control device for a dump truck according to the first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the present invention is applied to a dump truck.
[0009]
FIG. 1 is a block diagram showing the configuration of a dump truck using the body lifting / lowering speed control device for a dump truck according to the present embodiment.
[0010]
The driving force generated from the engine 10 is transmitted to the two driving wheels 30A, 30B via the transmission 15, the differential gear 20, and the axles 25A, 25B, and causes the body of the dump truck to travel. The axles 25A, 25B are provided with retarder brakes 35A, 35B for generating a braking force on the respective drive wheels 30A, 30B.
[0011]
One end of the body 35 is rotatably supported by the body 40 of the dump truck. The body 35 can be moved up and down by expanding and contracting a hydraulic cylinder 45. The hydraulic pressure supplied from a pump P driven by the engine 10 is supplied to the hydraulic cylinder 45 via an electromagnetic proportional valve 50.
[0012]
The angle θ of the body 35 with respect to the vehicle body 40 is detected by the body angle sensor 55 and is input to the controller 100. The controller 100 controls the electromagnetic proportional valve 50 according to the operation amount of the operation lever 60 operated by the dump truck operator to control the amount of expansion and contraction and the expansion and contraction speed of the hydraulic cylinder. Becomes variable. At this time, the controller 100 is configured to control the elevating speed of the body 35 in accordance with the body angle θ detected by the body angle sensor 50. For details, refer to FIGS. It will be described later.
[0013]
FIG. 2 is a system block diagram showing the configuration of the body lifting / lowering speed control device for the dump truck according to the present embodiment.
[0014]
The controller 100 includes a raising operation signal generating unit 110, a lowering operation signal generating unit 120, a raising operation speed coefficient pattern generating unit 130, a lowering operation speed coefficient pattern generating unit 140, and multipliers 150 and 155. ing.
[0015]
The raising operation signal creating means 110 and the lowering operation signal creating means 120 output a body speed signal or a body speed signal corresponding to the operating angle α of the operating lever 60, respectively. The speed signals output by the raising operation signal generating means 110 and the lowering operation signal generating means 120 are supplied to the electromagnetic proportional valve 50 via multipliers 150 and 155, respectively, to control the expansion and contraction speed of the hydraulic cylinder 45, and to raise and lower the body. Control the speed.
[0016]
The speed coefficient pattern generating means 130 at the time of raising operation and the speed coefficient pattern generating means 140 at the time of lowering operation are respectively provided with a speed coefficient signal at the time of the raising operation of the body according to the body angle θ detected by the body angle sensor 55 and a speed coefficient signal at the time of the lowering operation. Outputs a speed coefficient signal. The speed coefficient signals output by the speed coefficient pattern generating means 130 during the raising operation and the speed coefficient pattern generating means 140 during the lowering operation are supplied to the electromagnetic proportional valve 50 via the multipliers 150 and 155, respectively. A value obtained by multiplying the speed signal output by the raising operation speed coefficient pattern generating means 130 and the speed coefficient signal output by the lowering operation speed coefficient pattern generating means 140 to the speed signal output by the lowering operation signal creating means 120 is output. By controlling the expansion / contraction speed, the body elevating speed is controlled.
[0017]
Here, the hydraulic cylinder 45 is a two-stage stroke cylinder, and the first-stage stroke is L1 and the second-stage stroke is L2. The bottom area of the first-stage cylinder is A1, and the bottom area of the second-stage cylinder is A2. In the following description, when the body is raised, the first-stage cylinder is extended first, and the second-stage cylinder is extended from the switching point at which the first-stage cylinder is fully extended. On the other hand, when the body descends, it is assumed that the cylinder of the second stage first contracts, and then the cylinder of the first stage contracts from the switching point at which the cylinder of the second stage has completely contracted. L1 = L2, and 0.75 · A1 = A2.
[0018]
The speed coefficient patterns generated by the speed coefficient pattern generating means 130 during the raising operation and the speed coefficient pattern generating means 140 during the lowering operation will be described with reference to FIGS.
[0019]
FIG. 3A shows the speed coefficient pattern at the time of the raising operation generated by the speed coefficient pattern generating unit 130 at the time of the raising operation. The horizontal axis is the body angle θ detected by the body angle sensor 55, and the vertical axis is the vertical axis. This is the body up / down speed coefficient K. The body angle θ3 (for example, 30 °) is the angle of the switching point of the two-stage stroke cylinder. As shown in the figure, in a range where the body angle θ is small (θ = 0 to θ3 (for example, 30 °)), the speed coefficient K is set to 0.75. When the body angle θ is in the range of θ3 to θ4 (for example, 30 ° to 50 °), the speed coefficient K is 1.0. When the body angle θ is in the range of θ4 to θ5 (for example, from 50 ° to 55 °), the speed coefficient K gradually decreases to 1.0 to 0.25, and the body angle θ is in the range of θ5 to θ6 (for example, from 55 ° to 55 °). 60 °), the speed coefficient K is fixed at 0.25.
[0020]
The raising operation speed coefficient pattern generated by the raising operation speed coefficient pattern generating means 130 is multiplied by the operation signal output by the raising operation signal generating means 110 by the multiplier 150, so that, for example, the operation lever is held at a fixed angle. When the operation signal has a constant rising speed, the vertical axis in FIG. 3A indicates the rising speed of the body. That is, using the speed coefficient pattern generating means 130 during the raising operation, there is a relationship of 0.75 · A1 = A2 between the bottom area A1 of the first stage cylinder and the bottom area A2 of the second stage cylinder. In this case, the speed coefficient at the time of raising operation generated by the speed coefficient pattern generating means 130 at the time of raising operation is set such that the speed coefficient for the cylinder of the first stage is 0.75 times the speed coefficient for the second stage. The extension speed of the hydraulic cylinder before and after the switching point of the cylinder can be made equal, and the rising speed of the body can be made equal. When the body is lifted and the load in the body is scattered, the impact at the switching point can be reduced, so that the load can be prevented from scattering. In addition, the impact at the stroke end can be reduced by reducing the body rising speed from just before the stroke end (body angle θ6).
[0021]
FIG. 3B shows the speed coefficient pattern at the time of the lowering operation generated by the speed coefficient pattern generator at the time of the lowering operation. The horizontal axis indicates the body angle θ detected by the body angle sensor 55, and the vertical axis indicates the vertical axis. The axis is the body elevating speed coefficient K. As shown
In the range where the body angle θ is large (θ = θ6 to θ3 (for example, 60 ° to 30 °)), the speed coefficient K is set to 1.0. When the body angle θ is in the range of θ3 to θ2 (for example, 30 ° to 10 °), the speed coefficient K is set to 0.75. When the body angle θ is in the range of θ2 to θ1 (for example, 10 ° to 5 °), the speed coefficient K gradually decreases to 0.75 to 0.25, and the body angle θ is in the range of θ1 to 0 (for example, 5 ° to 5 °). 0 °), the speed coefficient K is fixed at 0.25.
[0022]
The multiplier 155 multiplies the operation signal output from the lowering operation signal generator 120 by the lowering operation speed coefficient generated by the lowering operation speed coefficient pattern generator 140, so that, for example, the operation lever is held at a fixed angle. When the operation signal has a constant lowering speed, the vertical axis in FIG. 3B indicates the lowering speed of the body. That is, using the speed coefficient pattern generating means 140 at the time of the lowering operation, there is a relationship of 0.75 · A1 = A2 between the bottom area A1 of the first-stage cylinder and the bottom area A2 of the second-stage cylinder. In this case, by setting the speed coefficient at the time of the lowering operation generated by the speed coefficient pattern generator 140 at the time of the lowering operation to be 0.75 times the speed coefficient for the cylinder of the first stage and the speed coefficient for the second stage, the two-stage stroke is obtained. The contraction speed of the hydraulic cylinder before and after the switching point of the cylinder can be made equal, and the descending speed of the body can be made equal. Further, by reducing the body descending speed from just before the stroke end (body angle 0), it is possible to reduce the impact at the stroke end.
[0023]
As described above, according to the present embodiment, the lifting and lowering of the body before and after the switching point of the two-stage stroke cylinder is achieved by using the speed coefficient pattern generating means 130 during the raising operation and the speed coefficient pattern generating means 140 during the lowering operation. The speed can be constant. In addition, at the time of spraying by the body raising operation, it is possible to prevent scattering at the switching point.
[0024]
Further, at the time of elevating the body, control is performed so as to reduce the elevating speed at the stroke end of the hydraulic cylinder that elevates the body based on the body angle detected by the body angle sensor 50, so that the impact at the stroke end can be reduced.
[0025]
Next, the configuration and operation of a body lifting / lowering speed control device for a dump truck according to a second embodiment of the present invention will be described with reference to FIG. The configuration of the dump truck using the body lifting speed control device for the dump truck according to the present embodiment is the same as the configuration shown in FIG. Further, the system configuration of the body lifting / lowering speed control device for the dump truck according to the present embodiment is the same as that shown in FIG.
[0026]
In the present embodiment, the speed coefficient patterns generated by the speed coefficient pattern generating means 130 during the raising operation and the speed coefficient pattern generating means 140 during the lowering operation are changed as shown in FIGS. 4 (A) and 4 (B). .
[0027]
FIG. 4A shows the speed coefficient pattern at the time of the raising operation generated by the speed coefficient pattern generating means 130 at the time of the raising operation. The speed coefficient pattern in the range of the body angles θ3 ′ to θ3 ″ (for example, 25 ° to 35 °) is changed from that shown in FIG. 3A. As illustrated, the range in which the body angle θ is small (θ = 0 to θ3 ′ (for example, 25 °), the speed coefficient K is 0.75, and when the body angle θ is in the range of θ3 ′ to θ3 (for example, 25 ° to 30 °), the speed coefficient K is 0.75 to 0.75. When the body angle θ is in the range of θ3 to θ3 ″ (for example, from 30 ° to 35 °), the speed coefficient K gradually increases to 0.5 to 1.0, and the body angle θ decreases. In the range of θ3 ″ to θ4 (for example, 35 ° to 50 °), the speed coefficient K is fixed at 1.0.
[0028]
Even with such a speed coefficient pattern at the time of the raising operation, the impact at the switching point of the two-stage stroke cylinder can be reduced by reducing the body rising speed at the switching point (θ3) of the two-stage stroke cylinder, and The body rising speed before and after that can be made equal.
[0029]
FIG. 4B shows a speed coefficient pattern at the time of the lowering operation generated by the speed coefficient pattern generator at the time of the lowering operation. The velocity coefficient pattern in the range of the body angles θ3 ′ to θ3 ″ (for example, 25 ° to 35 °) is changed from that shown in FIG. 3 (B).
In the range where the body angle θ is large (θ = θ6 to θ3 ″ (for example, 60 ° to 35 °), the speed coefficient K is 1.0. The body angle θ is in the range of θ3 ″ to θ3 (for example, 35 ° to 30 °). ), The speed coefficient K gradually decreases from 1.0 to 0.5, and when the body angle θ is in the range of θ3 to θ3 ′ (for example, 30 ° to 25 °), the speed coefficient K becomes 0.5 to 0. When the body angle θ is in the range of θ3 ′ to θ2 (for example, 25 ° to 10 °), the speed coefficient K is kept constant at 0.75.
[0030]
Even with such a speed coefficient pattern at the time of the lowering operation, the impact at the switching point of the two-stage stroke cylinder can be reduced by reducing the body descending speed at the switching point (θ3) of the two-stage stroke cylinder, and The body descending speed before and after that can be made equal.
[0031]
As described above, according to the present embodiment, the lifting and lowering of the body before and after the switching point of the two-stage stroke cylinder is achieved by using the speed coefficient pattern generating means 130 during the raising operation and the speed coefficient pattern generating means 140 during the lowering operation. The speed can be constant. In addition, at the time of spraying by the body raising operation, it is possible to prevent scattering at the switching point.
[0032]
Further, at the time of elevating the body, control is performed so as to reduce the elevating speed at the stroke end of the hydraulic cylinder that elevates the body based on the body angle detected by the body angle sensor 50, so that the impact at the stroke end can be reduced.
[0033]
Next, the configuration and operation of a body lifting / lowering speed control device for a dump truck according to a third embodiment of the present invention will be described with reference to FIG. The configuration of the dump truck using the body lifting speed control device for the dump truck according to the present embodiment is the same as the configuration shown in FIG. Further, the system configuration of the body lifting / lowering speed control device for the dump truck according to the present embodiment is the same as that shown in FIG.
[0034]
In the present embodiment, the speed coefficient patterns generated by the speed coefficient pattern generating means 130 during the raising operation and the speed coefficient pattern generating means 140 during the lowering operation are changed as shown in FIGS. 5A and 5B. .
[0035]
FIG. 5A shows the speed coefficient pattern at the time of the raising operation generated by the speed coefficient pattern generating means 130 at the time of the raising operation. Before and after the body angle θ3 (for example, 30 °) as the switching point, the speed coefficient K is gradually increased to 0.75 to 1.0.
[0036]
FIG. 5B shows the speed coefficient pattern at the time of the lowering operation generated by the speed coefficient pattern generator at the time of the lowering operation. Before and after the body angle θ3 (for example, 30 °) as the switching point, the speed coefficient K is gradually reduced to 1.0 to 0.75.
[0037]
As described above, according to the present embodiment, the lifting and lowering of the body before and after the switching point of the two-stage stroke cylinder is achieved by using the speed coefficient pattern generating means 130 during the raising operation and the speed coefficient pattern generating means 140 during the lowering operation. The speed can be constant.
[0038]
Further, at the time of elevating the body, control is performed so as to reduce the elevating speed at the stroke end of the hydraulic cylinder that elevates the body based on the body angle detected by the body angle sensor 50, so that the impact at the stroke end can be reduced.
[0039]
【The invention's effect】
According to the present invention, even when a two-stage stroke cylinder is used as the hydraulic cylinder, the body elevating speed can be made constant at the time of switching the cylinder.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a dump truck using a body lifting / lowering speed control device for a dump truck according to a first embodiment.
FIG. 2 is a system block diagram showing a configuration of a body lifting / lowering speed control device of the dump truck according to the first embodiment.
FIG. 3 is an explanatory diagram of a speed coefficient pattern generated by a speed coefficient pattern generation unit.
FIG. 4 is an explanatory diagram of a speed coefficient pattern generated by a speed coefficient pattern generation unit according to a second embodiment.
FIG. 5 is an explanatory diagram of a speed coefficient pattern generated by a speed coefficient pattern generation unit according to a third embodiment.
[Explanation of symbols]
10 Engine 15 Transmission 20 Differential gears 25A, 25B Axles 30A, 30B Driving wheels 35A, 35B Retarder brake 40 Body 45 Hydraulic cylinder 50 Electromagnetic proportional valve 55 Body angle sensor 60 Operating lever 65 Teaching / reproduction changeover switch 100 Controller 110 Generating raising operation signal Means 120 Lowering operation signal creating means 130 Speed coefficient pattern generating means at the time of raising operation 140 Speed coefficient pattern generating means at the time of lowering operation 150, 155 Multiplier

Claims (2)

A body provided on the vehicle body, a hydraulic cylinder for raising and lowering the body in a standing posture and a sitting posture, operating means, and control for controlling the vertical movement speed of the body by expanding and contracting the hydraulic cylinder in accordance with the operation of the operating means In the dump truck body elevating speed control device of the dump truck having the means,
The hydraulic cylinder is a two-stage stroke cylinder,
The above-mentioned control means controls the up-and-down speed of the body before and after the switching point of the two-stage stroke cylinder so as to be equal in speed. The body lifting / lowering speed control device for a dump truck according to claim 1,
Equipped with a body angle detecting means for detecting an elevation angle of the body,
The control means,
Speed coefficient pattern generation means for generating a speed coefficient pattern such that the vertical movement speed of the body at the switching point of the two-stage stroke cylinder is made equal, according to the body angle detected by the body angle detection means;
A body lifting / lowering speed control device for a dump truck, comprising a multiplying means for multiplying an output signal of the speed coefficient pattern generating means by an operation signal of the operating means.

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