JPH0716978Y2 - Load display device for cargo handling vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a load display device in a cargo handling vehicle such as a wheel loader.

<Prior Art> A conventional load display device for a cargo handling vehicle (wheel loader) is
As shown in FIG. 11, a load detector 1 for detecting the load of the cargo handling equipment and a position detector 2 for detecting the lifting position of the boom.
A true load value is calculated based on the load indicator 3 that displays the load value of the cargo loaded on the cargo tool, the load signal of the load detector 1, and the detected position signal from the position detector 2. In addition, it is provided with a control unit 4 which outputs a load value display signal to the load display 3 (see Japanese Utility Model Laid-Open No. 63-128429).

Reference numeral 5 is a power switch, 6 is a printer, 7 is a tail pressure detection unit, 8 is a rod pressure detection unit, 9a is a cancel switch, 9b is a cargo handling device posture detector, and 9c is a backward movement detector. Then, the tail pressure detection unit 7 and the rod pressure detection unit 8 constitute the loaded load detector 1.

<Problems to be solved by the invention> However, the conventional load display device only digitally displays the load value as shown in Fig. 12, and it depends on the operator's intuition to judge whether or not the load amount is safe. There is.

Therefore, if the operator is an inexperienced operator, if he / she makes a mistake in the judgment, a slip or lift of the rear wheel may occur, resulting in a dangerous state and a safety problem.

In view of the above, an object of the present invention is to provide a load display device for a cargo handling vehicle that displays whether cargo handling work is safe or not, and allows the operator to safely carry out cargo handling work even if the operator is inexperienced.

<Means for Solving the Problems> The means for solving the problems according to claim 1 of the present invention is, as shown in FIGS. 1 to 5, a boom 13 rotatably supported around a support shaft 12 with respect to a vehicle body 11, A load handling vehicle comprising a boom cylinder (14) for rotating the boom (13) and a cargo handling tool (16) rotatably supported around a horizontal axis (15) at the tip of the boom (13). Load detector 25 that detects the load handling tool 16, a cargo handling tool posture detector 29 that detects the rising state of the cargo handling tool 16, and a boom position detector 30 that detects the lifted position of the boom 13.
And an indicator X for displaying whether or not the cargo handling state is dangerous, and a display of the indicator X is controlled based on output signals from the load detector 25, the cargo handling tool posture detector 29 and the boom position detector 30. A control circuit 31 is provided, and the control circuit 31 determines whether or not the rising state of the cargo handling tool 16 is the last tilt based on the output signal from the cargo handling tool posture detector 29. Means 41a, a lift angle determination means 41b for determining whether or not the boom 13 has rotated to a lift angle at which a maximum load is applied based on an output signal from the boom position detector 30, and the rising state determination means When 41a determines the last tilt of the material handling implement 16 and the lift angle determination means 41b determines the maximum load lift angle of the boom 13, the cargo implement attitude detector 29 based on the output signal from the load detector 25. Whether or not the load on the engine is above a certain level Load determining means 42 for determining, when said load determination means 42 has determined the predetermined value or more of the boom cylinder load, in which a display switching means 43 to dangerous zone display of the indicator X.

<Operation> In the problem solving means according to claim 1, when the cargo handling tool 16 reaches the final tilt, the cargo handling tool posture detector 29 detects this, and the rising state determination means 41a in the control circuit 31 detects this. Based on the above, it is determined that the cargo handling implement 16 is tilted to the end, and it is output to the load determination means 42.

Next, when the boom 13 reaches the lift angle at which the maximum load is applied,
The boom position detector 30 detects this, and the lift angle determination means 41
b determines that the boom 13 has the maximum load elevation angle,
Output to the load determination 42.

In this way, the load discriminating means 42 includes the rising state discriminating means.
When the final tilt determination signal from 41a and the maximum load lift angle determination signal from the lift angle determination means 41b are input, the load determination means 42 determines the load applied to the boom cylinder 14 based on the detection signal from the load detector 25. Determine.

At this time, when the load determining means 42 determines that the boom cylinder load is equal to or more than a certain value, the indicator switching means 43
Sets the display on the display unit X to the dangerous area based on the load discrimination result.

<Embodiment> An embodiment of a load display device for a cargo handling vehicle according to the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a functional block diagram of a load display device for a cargo handling vehicle according to the first embodiment of the present invention, FIG. 2 is a control flow chart thereof, and FIG. 3 is a load. FIG. 4 is a side view of the cargo handling vehicle, showing the correspondence between the tail pressure of the detector and the display lamp.

Generally, as shown in FIG. 4, a cargo handling vehicle (wheel loader) includes a boom 13 rotatably supported on a vehicle body 11 around a support shaft 12, and a boom cylinder 14 for rotating the boom 13. A cargo handling tool (bucket) 16 rotatably supported on the tip of the boom 13 about a horizontal axis 15, and the bucket.
A bucket cylinder 17 for rotating 16 is provided.

The bucket 16 is connected to a bucket cylinder 17 via a link mechanism 18. Then, the link mechanism 18 includes the first arm 20 rotatably supported by the boom 13 about the axis 19.
And a second arm 21 connected to the back surface of the bucket 16. One end of the first arm 20 has a bucket cylinder 17
The other end is connected to the second arm 21, respectively. As a result, the bucket 16 is in a state where the scooping is started (the most forward tilted posture) 16A and is finished to be scooped (the last tilted posture) 1
It becomes possible to rotate between 6B.

In the figure, reference numeral 22 denotes a bucket raising lever, the bucket 16 is rotated by the bucket raising lever 22, and the boom cylinder is extended by stepping on an accelerator of the vehicle body.

The load display device of the present embodiment, as shown in FIG. 1, is a load detector that detects the load applied to the boom cylinder 14.
25, a cargo handling tool posture detector 29 that detects the rising state of the cargo handling tool 16, a boom position detector 30 that detects the lifting position of the boom 13, and a color-coded display indicating whether the cargo handling status is dangerous. Indicator X, the load detector 25, the cargo handling tool posture detector 20
And a control circuit 31 for controlling the color display of the display X based on the output signal from the boom position detector 30.

The load detector 25 is a pressure sensor that detects the tail pressure of the boom cylinder 14, and the pressure sensor 25 is a third pressure sensor.
As shown in the figure, when the bucket 16 is tilted to the end,
If the tail pressure is P3 corresponding to the fall load, the voltage V3
If the tail pressure is P2 corresponding to the normal load, the voltage V2
When the tail pressure is the lowest reference tail pressure P1 (= P2 / 2), the voltage V1 is output.

The cargo handling tool posture detector 29 is a proximity switch that is attached to the bucket cylinder 17 and is turned on when the bucket 16 is tilted to the end.

The boom position detector 30 is a proximity switch that is attached to the boom cylinder 14 and is turned on when the boom 13 is rotated to a lift angle at which the maximum load is applied. Here, the lift angle at which the maximum load is applied refers to a range of about + 10 ° from the boom position during loading.

The indicator X includes a green lamp 26 that lights up when the tail pressure of the cylinder 14 is in a normal load position (P1 to P2), and a yellow lamp 27 that lights up in an intermediate load position (P2 to P3). It consists of a red lamp 28 that lights up when the vehicle is in a fall load position (P3 or higher).

The control circuit 31 is a one-chip micro computer, and as shown in FIG. 1, determines whether or not the rising state of the cargo handling implement 16 is the last tilt based on the output signal from the cargo handling implement posture detector 29. A rising state determination means 41a for determining, and a lift angle determination means 41b for determining whether or not the boom 13 is rotated to a lift angle at which a maximum load is applied based on an output signal from the boom position detector 30, When the rising state determination means 41a determines the final tilt of the cargo handling device 16 and the lift angle determination means 41b determines the maximum load lift angle of the boom 13, the output signal from the load detector 25 The load on the cargo handling device attitude detector 29 is
A load discriminating means 42 for discriminating which of the normal load position, the intermediate load position and the overturning load position, and a green lamp 26 for displaying an intermediate load position when the load discriminating device 42 judges the normal load position. When it is determined that the yellow lamp 27,
And a display switching means 43 for turning on the red lamp when it is determined that the vehicle is in a fall load position.

In the above structure, as shown in FIG. 4, the vehicle is moved forward, the bucket 16 is tilted to the frontmost tilted position 16A, and the bucket 16 is rotated upward from the frontmost tilted position 16A to the last tilted position 16B to move the debris into the bucket 16. And so on.

Then, the boom cylinder 14 is driven to rotate the boom 13 upward to the maximum elevation angle.

After that, the vehicle is moved backward and the earth and sand in the bucket 16 such as a truck is loaded.

By the way, when the bucket 16 reaches the final inclination, the cargo handling tool posture detector 29 detects this and outputs an output signal to the control circuit 31. Then, the rising state discriminating means 41a in the control circuit 31 judges that the bucket 16 is in the rearward rising state.

Next, when the boom 13 reaches the lift angle at which the maximum load is applied,
The boom position detector 30 detects this and outputs an output signal to the control circuit 31. Then, the lift angle determination means 41b in the control circuit 31 determines that the boom 13 has the maximum load lift angle.

Then, the load control means 42 is provided with the rising state determination means 41a.
When the final inclination determination signal from the vehicle and the maximum load elevation angle determination signal from the elevation angle determination means 41b are input, the load determination means
Reference numeral 42 determines the tail pressure of the boom cylinder 14 based on the detection signal from the load detector 25, and the display switching means 48 controls the color display of the display X based on the determination result.

Here, the color-based display system will be described with reference to the flowchart of FIG.

The tail pressure P of the boom cylinder 14 is the normal load level (P1 to P2)
In the range of, the indicator switching means 43 turns on the green lamp 26, turns on the yellow lamp 27 at the intermediate load position (P2 to P3), and turns on the red lamp at the fall load position (P3 or more). 28
Light up.

In this way, a load detector 25 that detects the load applied to the boom cylinder 14, a cargo handling device posture detector 29 that detects the rising state of the bucket, and a boom position detector 30 that detects the lifting position of the boom 13, An indicator X for displaying whether or not the cargo handling state is dangerous is provided. In the control circuit 31, the rising state discriminating means 41a discriminates the last inclination of the bucket 16, and the lift angle discriminating means 41b raises the maximum load of the boom 16. When you judge the high angle,
When the load discriminating means 42 discriminates based on the output signal of the load detector 25 that the load applied to the cargo handling tool posture detector 29 is above a certain level, the indicator switching means 43 sets the color display of the indicator X to the dangerous area. Since it is configured, the worker can easily detect the dangerous state simply by looking at the display X.

Therefore, even if the worker is inexperienced, it is possible to prevent the vehicle from being in a dangerous state by further depressing the accelerator and to perform safe work.

[Second Embodiment] FIG. 5 is an electric circuit diagram of a load display device of a second embodiment corresponding to claim 1 of the present invention.

In this embodiment, as shown in FIG. 5, the color-coded display of the dangerous state is electrically and mechanically controlled.

Then, the load detector 25, three pressure switches 51, 52, 53 connected in series with each other, and a contact is connected to this series connection body to control the energization of the pressure switches 51, 52, 53. It is composed of a one-lead switch 64.

In the pressure switch, the tail pressure P of the boom cylinder 14 is
When P1 ≦ P <P2, the switch 51 is turned on and the tail pressure P is
When P2 ≦ P <P3, the switches 51 and 52 are turned on, and when the tail pressure P is P3 ≦ P, the switches 51, 52 and 53 are turned on, and the first induction switch 64 is Coil 64
It is composed of a and a contact 64b which is turned on by its excitation.

The rising state determination means 51a includes a second induction switch 6 including a coil 65a and a contact 65b which is turned on by its excitation.
Is 5.

The lift angle determining means 41b is a third induction switch 66 including a coil 66a and a contact 66b, like the second induction switch 65.

Then, the contacts 65b and 66b of the second and third induction switches 65 and 66, respectively.
And the coil 64a of the first induction switch 64 are connected in series, and the first induction switch 64 is turned on by turning on the coils 65a and 66a.
Is turned on.

Further, the load discriminating means 42 and the induction switch have a contact point 67a between the connection intermediate point of the pressure switches 51 and 52 and the green lamp 26.
First inversion induction switch 67 and pressure switch
The pressure switch 53 is connected to the red lamp 28 by providing a second inversion induction switch 68 having a contact point 68a connected between the contact point midpoints of 52 and 53 and the yellow lamp 27.

The coil 67b of the first inversion induction switch 67 is connected in parallel to the contact 68b of the second inversion induction switch 68, and is also connected to the connection circuit of the red lamp 28 via the diode 69.

The coil 68b of the second inverting induction switch 68 is connected to the anode side of the diode 69.

As a result, when the pressure switch 51 is turned on, the green lamp 26 is turned on, and when the pressure switches 51 and 52 are turned on, the coil 67b of the first inversion induction switch 67 is excited and its contact 67a is turned off. When only 27 is turned on and all the pressure switches 51, 52, 53 are turned on, the coils 67b, 68b of the first and second inversion induction switches 67, 68 are excited and their contacts 67a, 68a.
Turns off and only the red lamp 28 lights up.

As described above, since the lamps 26 to 28 are turned on according to the tail pressure of the boom cylinder 14, the action and effect are similar to those of the first embodiment.

[Third Embodiment] FIG. 6 is a functional block diagram of a load display device according to a third embodiment of the present invention, FIG. 7 is a view showing a state in which the running force of the vehicle body is fully applied, and FIG. FIG. 9 is a diagram showing a state where the rear wheels of the vehicle body are floating, FIG. 9 is a diagram showing a fully lit state of the indicator at full power, and FIG. 10 is a diagram showing a half lit state when the vehicle is slipping. Is.

In the present embodiment, as shown in FIG. 6, the load applied to the boom cylinder 14 at all times, that is, when the vehicle is moving forward in the scooping operation and when the boom 13 is lifted, is displayed. A load detector (pressure sensor) 25 that detects the tail pressure of 14, a display X that displays whether the vehicle is in a dangerous state, and a load display by the display X based on the detection signal from the load detector 25 are controlled. Control circuit 31
It has and.

The indicator X uses a linear meter having a plurality of LED lamps 1 to 1n in order to indicate to the operator whether the vehicle is in a dangerous state or not. It is configured so that the tail pressure of the cylinder 14 is fully lit when the maximum pressure is applied.

Then, the control circuit 31 is a load discriminating means 42 for discriminating a change in the load applied to the boom cylinder 14 based on a detection signal from the load detector 25, and a boom cylinder load of the boom cylinder load based on the discrimination result from the load discriminating means 42. Display switching means 43 for switching lighting of each of the lamps 1 to 1n of the display X according to the amount of change.
It consists of and.

In the above structure, when the scooping operation is performed in the full power state as shown in FIG. 7, the pressure applied to the tail of the boom cylinder 14 becomes the maximum pressure. Then, the load detector 25 detects this maximum pressure and outputs it to the control circuit 31. Then, the load discriminating means 42 of the control circuit 31 discriminates that the tail pressure of the boom cylinder 14 is the maximum pressure, and the indicator switching means 43 fully turns on the indicator X based on this, as shown in FIG. .

By the way, when the scooping operation is performed in the full power state, the rear wheel of the vehicle body may float, as shown in FIG. However, if the indicator X is fully lit and the operator confirms this and reduces the accelerator depression amount, the dangerous state can be avoided.

Further, when the tire slips, the tail pressure of the boom cylinder 14 decreases by the amount of the slip.

At this time, the load detector 25 detects the decrease in the pressure, the load determining means 42 determines the decrease in the pressure based on the decrease, and the display switching means 43 illuminates the display X halfway as shown in FIG. . If the operator confirms this and returns the accelerator, the dangerous state due to the slip can be avoided.

On the other hand, when the boom 13 is lifted, the load applied to the boom cylinder 14 is similar to the load amount of earth and sand in the bucket 16, so that the operator can use the load amount displayed on the display X as a guide to load the earth and sand. It is possible to determine what the amount is.

In this way, by displaying the load during the cargo handling work to the operator by the meter, it becomes a guide for wasteful accelerator work and lever operation, and the work can be performed safely and efficiently.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, the first embodiment and the third embodiment, and the second embodiment and the third embodiment may be combined to display the dangerous states at both the scooping and the lifting.

<Effect of the Invention> As is apparent from the above description, according to claim 1 of the present invention, the load detector for detecting the load applied to the boom cylinder, the cargo handling device attitude detector for detecting the rising state of the bucket, and the boom. A boom position detector that detects the lifted position and a display that displays whether the cargo handling state is dangerous or not are provided.
In the control circuit, when the rising state determination means determines the last inclination of the bucket and the lift angle determination means determines the maximum load lift angle of the boom, the load determination means determines the load handling posture based on the output signal of the load detector. When the load applied to the detector is determined to be above a certain level, the indicator switching means is configured to place the display on the indicator in the dangerous area, so that the worker can easily detect the dangerous state simply by looking at the indicator. .

[Brief description of drawings]

FIG. 1 is a functional block diagram of a load display device for a cargo handling vehicle according to the first embodiment of the present invention, FIG. 2 is a control flow chart thereof, and FIG. 3 is a tail pressure of a load detector. FIG. 4 is a side view of the cargo handling vehicle, showing the correspondence with the display lamps. FIG. 5 is an electric circuit diagram of a load display device of a second embodiment corresponding to claim 1 of the present invention. FIG. 6 is a functional block diagram of the load display device of the third embodiment of the present invention, FIG. 7 is a diagram showing a state in which the running force of the vehicle body is fully applied, and FIG. 8 is a rear wheel of the vehicle body during loading. FIG. 9 is a diagram showing a floating state, FIG. 9 is a diagram showing a fully lit state of the indicator at full power, and FIG. 10 is a diagram showing a half lit state when the vehicle is slipping. FIG. 11 is a control function block diagram of a conventional load display device for a cargo handling vehicle, and FIG. 12 is a front view of the same display device. 11: Vehicle body, 12: Support shaft, 13: Boom, 14: Boom cylinder, 15: Horizontal axis, 16: Cargo tool, 25: Load detector, 29: Cargo tool attitude detector, 30: Boom position detector, 31: control circuit, 41a: rising state determination means, 41b: elevation angle determination means, 42: load determination means, 43: display switching means, X: display.

Claims (1)

[Scope of utility model registration request] 1. A boom rotatably supported by a vehicle main body around a support shaft, a boom cylinder for rotating the boom, and a boom rotatably supported by a tip end of the boom around a horizontal axis. A load handling vehicle including: a load detector that detects a load applied to the boom cylinder; a load handling tool posture detector that detects a rising state of the load handling tool; and a lifting position of the boom. A boom position detector that detects the load, a display that indicates whether the cargo handling status is dangerous, and a display for the indicator based on the output signals from the load detector, cargo handling tool posture detector, and boom position detector. A control circuit for controlling is provided, and the control circuit is a rising state determination unit that determines whether or not the rising state of the cargo handling implement is the last tilt based on the output signal from the cargo handling implement posture detector. , Said A lift angle determination means for determining whether or not the boom is rotated to a lift angle at which a maximum load is applied based on an output signal from a boom position detector, and the rising state determination means determines the final tilt of the cargo handling tool. Then
And when the lift angle determining means determines the maximum load lift angle of the boom, a load for determining whether or not the load applied to the cargo handling tool posture detector is equal to or more than a certain value based on the output signal from the load detector. A load display of a cargo handling vehicle, comprising: a determining unit; and a display unit switching control unit that makes the display of the display unit a dangerous area when the load determining unit determines that the boom cylinder load is equal to or more than a certain value. apparatus.