JPH0435373B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a safety device for a three-roll dump truck.

(Prior art) Conventionally, in a three-turn dump truck, hinges are provided at four locations on the front, rear, left, and right between the chassis and the cargo box, and the hinges are composed of a hinge shaft, a shaft receiver, and a hook, and the The cargo box is tilted in the desired direction by rotating it according to the box tilting direction, locking and releasing the corresponding hinge shaft, and extending the hydraulic cylinder using the cargo box tilting operation lever. (For example, see Japanese Patent Application Laid-Open Nos. 56-50822 and 1983-1003629).

(Problems to be Solved by the Invention) In the above-described structure, the hooks are positioned in either the locked state or the released state, but each hook may malfunction due to an erroneous operation or the like. If you tilt the cargo box without doing so, there is a risk that the cargo box may fall from the undercarriage.

The present invention has been made in view of the above points, and provides a three-turn dump truck that ensures work safety by preventing the upward operation of the switching valve while switching to the hinge state corresponding to the selected tilting direction. This is what we provide.

(Technical means for solving the problem) The present invention provides a hinge switching actuation device that selectively operates a hinge between a locked state and a released state, and a selection switch that selects a hinge corresponding to each tilting direction. an actuating switch for actuating the hinge switching actuating device; a detecting means for detecting whether the switching actuation time is within a set time; and a lashing device for lashing the switching operation of the switching valve; While the hinge switching actuating device is being switched to the hinge state in the selected tilting direction by the switch or operation switch, and when the switching operation time has passed the set time, the switching operation of the switching valve is disabled via the lashing device. It has the following configuration.

(Example) Examples of the present invention will be described below with reference to the drawings.

In Fig. 1, a hinge shaft 3 in the longitudinal direction of the vehicle body is fixed to each bracket 2 protruding from the bottom of a cargo box 1 of a tri-turn dump truck at four locations on the front, rear, left, and right. Shaft receiving members 5 are fixedly installed at four locations on the front, rear, left and right sides of the chassis 4,
A hook 6 is rotatably supported on the shaft receiving member 5 (see FIG. 3), and hinges are formed at four locations between the bottom of the cargo box 1 and the chassis 4, front, rear, left, and right.

As shown in detail in FIG. 2, a reed switch main body 7a is provided via a bracket to a lower frame 4a of the closed cross-section structure extending in the vehicle width direction of the vehicle chassis 4, and a cargo box corresponding to the lower frame 4a is provided. 1
A magnet 7b is provided via a bracket to an upper frame 1a of a closed cross-sectional structure extending in the vehicle width direction at the bottom. The reed switch body 7a and the magnet 7b constitute a reed switch 7, which is a box detection switch that detects whether or not the cargo box 1 is in the lowered position. It is designed to turn on at certain times.

Reference numeral S denotes a cargo box tilting operation lever for operating the raising and lowering motion of the cargo box 1, and is provided in the driver's cab. This cargo box tilting operation lever S is connected to a shifter of a power take-off device (PTO) 9 and a hydraulic pump 10 via a cable 8.
The hydraulic pump 10 is connected to a spool 11 of a switching valve integrally formed with the hydraulic pump 10.

By the way, a limit switch is provided on the outer periphery of the spool 11 to detect the switching position of the switching valve.
The moving parts of LS2 are in contact with each other.

The spool 11 is formed to have a larger diameter at its end so as to press the movable part of the limit switch LS2 when the spool 11 is switched from the lowered position to the intermediate position and the raised position via the cargo box tilting operation lever S. .

As a result, the limit switch LS2 is activated only when the spool 11 of the switching valve is in the lowered position.
It's starting to turn on.

On the other hand, a solenoid SOLa is disposed at a position facing the spool 11 of the switching valve, and a bell crank 13 is rotatably connected to the solenoid SOLa via a pivot shaft 12.

The bell crank 13 is normally located at a lower position where the spool 11 is opened by the biasing force of the spring 14, and the solenoid is activated as described later.
When SOLa is excited, its attractive force turns the bell crank 13 to face the front of the spool 11 against the biasing force of the spring 14, thereby preventing the spool 11 from switching to the raised position. be. In this way, the solenoid SOLa and the bell crank 13 constitute a securing means.

Further, each of the aforementioned hooks 6 is attached to the hinge shaft 3.
is fixed to the shaft receiving member 5, and is constantly biased in the release direction by a spring (not shown).
It is held at a locking position P2 by a stopper 19 rotatably supported by the shaft receiving member 5.

This stopper 19 is linked to a hinge switching actuating device 21 via a rod member 20 inserted into the frame 4a, and this hinge switching actuating device 21 is connected to an electric motor M and connected to the electric motor M. Although a detailed explanation will be omitted, the speed reducer 22 converts rotational motion into linear reciprocating motion.

Therefore, the reciprocating movement of the locking member 20 by the hinge switching actuating device 21 moves the hook 6 to the stop position P3, which holds the hook 6 at the locking position P2, and to the stop position P3, which holds the hook 6 at the locking position P2.
The stopper 1 is moved between the stop release position P5, which releases the lock and allows rotation to the lock release position P4.
9 is designed to rotate.

B is an operation panel, which includes a selection switch SW for selecting a hinge state corresponding to the tilting direction of the cargo box, and an operation switch PB for driving the hinge switching actuation device 21.
1. A reversing switch PB2 and pilot lamps PL1 to PL4 are provided for driving the hinge switching actuating device 21 in the opposite direction.

C is a control box that houses the control system, and BZ is an alarm buzzer.

By the way, as shown in the electric circuit diagram of FIG. 4, the present invention includes a power source BT, engine key switch E, selection switch SW, operating switch PB1, reverse switch PB2, limit switches LS1, LS2, relays CR1, CR2, Y1, Y2, Y3, Y4, Y
5, Y6, Y7, Y8, Y9, Y10, Y11,
Y12, X1, X2, X3, X4, X5, X6,
X7, X8, R1, R2, R3, R4 and their relay contacts cr1, cr2, y1, y2, y3, y4,
y5, y6, y7, y8, y9, y10, y1
1, y12, x1, x2, x3, x4, x5, x
6, x7, x8, r1, r2, r3, r4, timer relays T1, T2, electric motors M1, M2, M3, M4 that constitute the hinge switching actuator, buzzer
BZ, solenoid SOLa, pilot lamp PL1,
PL2, PL3, PL4, movable terminals m1, m that are provided integrally with the electric motor M and detect the rotational state thereof.
2, m3, and m4 are connected by wires as appropriate.

The electric motors M1 to M4 are arranged as shown in FIG. 7, and the positions of the movable terminals m1 to m4 shown in FIG. The hinges represent the state in which the stopper 19 is in the stop position P3, and the front left and front right hinges are in switching the stopper 19 to the stop release position P5.

Next, the operation of the present invention will be explained.

When engine key switch E is turned on, the relay
As a result of CR1 being energized, its relay contact cr1 is closed and pilot PL1 lights up.

Now, when the cargo box 1 is in the traveling state, that is, the cargo box 1 is lowered, the switching valve is in the lowered position, and the hinge is in the backward dump state, the electrical contact LS
1, LS2 are respectively closed, and relays X1,
While X4, X5, and X8 are energized, relay
2, X3, X6, and X7 are not energized.

Therefore, in this state, relay contacts x1, x
As a result, the current from relay contacts y2, y4 lights up the pilot lamp PL3, and the operator is instructed to move the hinge backwards. Notify that it is in the dump state.

That is, it is notified that the rear left and rear right stoppers 19 are at the stop position P3, and the front left and front right stoppers 19 are at the stop release position P5.

Here, when selecting the left dump, by switching the selection switch SW from position to position and turning on the operating switch PB1, the power supply voltage will be applied to the relay contact CR1, the electrical contacts LS1, LS2, the operating switch PB1, and the relay. Relay Y1 via contact y8,
Energize Y2. When relay Y1 is energized, relays Y1 and Y2 are self-held via relay contact y1, and as a result, they continue to be energized even if actuation switch PB1 is released.

On the other hand, in order to energize the solenoid SOLa by closing the contact y1 of the relay Y1, the bell crank 13 is rotated to a position facing the spool 11 of the switching valve, making it impossible to raise the switching valve.

Then, at the same time as energizing the solenoid SOLa,
Timer relay T1 is also energized, and when the set time has elapsed, relay Y7 is energized, and timer relay T2 and relay CR2 are energized via the switched contacts y7 and y2.

Therefore, the electric motors M1 to M4 are allowed to be energized via the relay contact cr2 and the reverse switch PB2 for only the set time of the timer relay T2. Here, the selection switch SW is switched to the position, and the relays X1, X4, X5,
Since X8 is energized, relay contact y
9, relay R3 via x5, and relay R2 and relay Y10 via relay contacts y9, x4.
are energized respectively, and their relay contacts r2, r
3 and Y10.

Therefore, the current from the relay contact cr2 flows through the reversing switch PB2 to the relay contact r1, the electric motor M1, the relay contact r4, and the electric motor M4, thereby driving the electric motors M1 and M4 to rotate, respectively.

As the electric motors M1 and M4 rotate, the M1 movable terminal m1 rotates from the upper position to the lower position to demagnetize the relay X1 and energize the relay X2, and the M4 movable terminal m4 rotates from the lower position to the upper position. position to demagnetize relay X8 and energize relay X7.

As a result, relays X2, X4, X5, and X7 are energized, and relays X1, X3, X6, and X8 are demagnetized.

Excitation of relay X2 energizes relay R1 via its relay contact x2, and excitation of relay X7 energizes relay R4 via its relay contact x7, so those relay contacts r1 and r4 are opened, and the electric motor is The current flowing through M1 and M4 is cut off to stop their rotation.

On the other hand, the flow flows through relay contacts x4, x5, x2, x7 to relay Y3, which lights pilot lamp PL2 through relay contact y3, indicating that the hinge state is in the left dump position, that is, the front left and rear left. The operator is informed that the stopper 19 is at the stop position P3 and that the front right and rear right stoppers 19 are at the stop release position P5.

These hinges are switched within the time set by the above-mentioned timer relay T2, and when the set time elapses, relay Y8 is energized.
Demagnetize relays Y1 and Y2 and cut off power to timer relay T2 and relay CR2.

Furthermore, since relay contacts y3, y1, and y10 are switched, power to timer relay T1 and solenoid SOLa is also cut off.

As a result, the spool 11 of the switching valve is allowed to move, so if the cargo box tilting operation lever S is operated after this, the PTO 9 is operated and at the same time, the spool 11 of the switching valve is switched to the raised position, as shown in the figure. The dump cylinder extends and the cargo box 1 tilts to the left around the left hinge.

On the other hand, if you want to dump to the right after this, move the selection switch SW to the position and turn the operation switch
All you have to do is touch PB1.

In other words, as mentioned above, relay contact CR2 and reverse switch PB are activated for the set time of timer relay T2.
2, electric motors M1 to M4 are energized.

In this case, depending on the switching of the selection switch SW, the current only energizes the relay Y12, and the relays R1, R2, R3, and R4 are not energized because their respective relay contacts x1, x3, x6, and x8 are open.

Therefore, the power supply voltage is applied from the reversing switch PB2 to all the electric motors M1 to M4 through relay contacts r1, r2, r3, and r4, driving them to rotate.

Therefore, the contacts of the movable terminal m1 for M1 and the movable terminal m2 for M2 are switched from the lower position to the upper position, and the contacts of the movable terminal m3 for M3 and the movable terminal for M4 are switched from the upper position to the lower position.

When these movable terminals switch, relay X1,
X3, X6, X8 are energized, and relays X2,
X4, X5, and X7 are demagnetized. Therefore, the relays R1, R2, R3, and R4 are excited via the energized relay contacts x1, x3, x6, and x8, and the rotation of the electric motors M1 to M4 is stopped.

In this state, relay contacts x1, x8, x3,
In order to energize relay Y5 via x6 and light up pilot lamp PL4 via its relay contact y5, the hinge is in the right dump state, that is, the front right and rear right stoppers 19 are in the stop position P3.
The operator is informed that the front left and rear left stoppers 19 are at the stop release position P5. When the set time of timer relay T2 has elapsed,
Since the excitation of relay CR2 is cut off, energization of the electric motor is blocked.

After this, if you operate the cargo box tilting operation lever S,
The cargo box 1 tilts to the right around the right hinge.

After this, if you want to select rear dump, you only need to switch the selection switch SW to the position and operate the actuation switch PB1.In that case, relay contact CR2 is operated for the time set by timer relay T2. , the electric motors M2 and M3 are driven to rotate via the reversing switch PB2, and when their movable terminals m2 and m3 reach the lower and upper positions, the relays R2 and R3 are energized to stop the rotation of the electric motors M2 and M3. make it stop.

What has been described so far is the case of switching from the rear dump hinge state to the left dump hinge state, right dump hinge state, and rear dump hinge state, but it is not necessary to follow this procedure.
Any hinge state can be switched to a desired hinge state.

Also, if the selection switch SW is switched but the operating switch PB1 is not engaged,
The pilot lamp in the previous hinged state will light up without switching to that hinged state, and in this case, it will be considered an erroneous operation and the spool 11 of the switching valve will not be able to be operated to the raised position, and after the set time elapses, the pilot lamp will light up. I am trying to make the buzzer BZ sound.

For example, if we consider that the hinge is currently in the backward dump state, left dump is selected, and the selection switch SW is in the position, but the operating switch PB1 is not touched, the hinge is in the backward dump state, so the relay X1, X4, X5, and X8 are energized, and relay Y is activated via selection switch SW.
1, R2 and R3, and relay R1
and R4 are not excited. Therefore, although relay contacts r1 and r4 are closed, the operating switch
Since PB1 is not operated, relay CR2 is not excited and electric motors M1 and M4 are not driven to rotate.

In other words, since the hinge remains in the backward dump state, relay contacts x1, x4, x5, x8
relay Y4 is energized via , and pilot lamp PL3, which displays the hinge status of the rear dump truck, is lit. The lighting of this pilot lamp PL3 is
Different from the hinge state of the selected left dump.

At this time, since the selection switch SW is in the position, relays Y11 and Y12 are de-energized, and the current flows through the relay contacts y2, y4, y11 to the solenoid SOLa and timer relay T1.
, and prevents the spool 11 of the switching valve from being operated upward, and also causes the buzzer BZ to sound via relay contacts y7 and y2 after the set time has elapsed.
As a result, the worker may mistake the lighting of pilot lamp PL3 for the lighting of pilot lamp PL2 of the left dump truck, and even if the worker attempts to operate the cargo box tilting operation lever S, the cargo box will not be able to be tilted, and the buzzer BZ will be turned off. It sounds to notify the operator of an incorrect operation. In this case, when the operator touches the operating switch PB1, the electric motors M1 and M4 are driven to rotate, their movable terminals are switched, the stopper 19 is activated to the desired hinge state, and the buzzer BZ is activated. stops.

In this way, relays X1, X4, X5, and X8 are energized in the hinge state during rearward dumping, relays X2, X4, X5, and X7 are energized during leftward dumping, and relays X1, X3, and X8 are energized during rightward dumping. X
6 and X8 are each excited.

Therefore, when the hinge is in a halfway state, that is, when the arbitrary stopper 19 holds the hook 6 at the locking position P2, the stop position P3 is reached.
and the stop release position P5, where the hook 6 is released from the lock and allowed to rotate to the release position P4, the movable terminal does not reach either the upper position or the lower position, and the movable terminal Neither of the pair of relays connected to is energized.

For example, as mentioned above, in order to select the left dump from the rear dump hinge state, the selection switch SW
When the operating switch PB1 is operated after switching to the position, the electric motors M1 and M4 are rotationally driven.
The movable terminal for M1 rotates to the lower position, and the movable terminal for M4 rotates to the upper position, but let us assume here that the front left stopper 19 cannot be rotated to the stop position P3 due to gravel or the like. , relays X1 and X2 cannot be formed, so relay Y3 is not energized and pilot lamp PL2 is not lit.

When the set time of timer relay T2 has elapsed in this state, the excitation to relay CR2 is cut off to cut off the flow of current to electric motors M1 and M4.

At the same time, since relays Y4 and Y5 are not energized, current flows through these relay contacts y3, y4, and y5 to solenoid SOLa and timer relay T1, which first switches spool 11 of the switching valve to the raised position. , and after a set time elapses, relay Y7 is energized. This energization of relay Y7 switches its relay contact y7 and energizes buzzer BZ, thereby notifying the operator that the hinge state is above.

In this case, since the other hinges are normal, relays X5 and X7 are energized, and energization by turning the selection switch SW to the position energizes relays R2, R3, and R4. Here, when operating switch PB1 and reversing switch PB2 are simultaneously operated, timer relay T1 is energized, and after the set time elapses, timer relay T2 is energized, and as a result, relay CR2 is energized for the set time.

Therefore, the current flows to relay contact cr2, reverse switch PB2, electric motor M1, and relay contact r1, and as a result of the current flow direction (polarity) being reversed, electric motor M1 is driven in reverse.

Therefore, the movable terminal m1 for M1, which had stopped mid-rotation from the upper contact point toward the lower contact point, now rotates in the direction of returning to the upper position again, and as a result, the energization process of relay X1 is formed. .

However, since relay X2 is not energized, when the set time of timer relay T2 has elapsed, the circuit to electric motor M1 is cut off and the reverse drive of electric motor M1 is stopped.

At the same time, relays Y3, Y4, and Y5 are also not energized, and the current flows through these relay contacts y3, y4, and y5 to timer relay T1 and solenoid SOLa, thereby preventing the switching valve from being raised.

Then, after the set time of timer relay T1, the buzzer BZ again issues an alarm via relay contacts y7 and y2.

Then, the current flows again to the selection switch SW (position), the reverse switch PB2, the relay contact r1, and the electric motor M1 to rotate the electric motor M1 in the forward direction, so the movable contact m1 for M1 is moved from the upper position to the lower position. Rotation is started again, and the front left hinge is rotated so as to be secured, that is, to move the stopper 19 to the stop position P3.

If the buzzer BZ is still sounding even after operating in this way, check the hinge part for any obstructions, etc., remove any obstructions, and then perform the same operation again. good.

In the embodiments of the present invention, the switching valve is mechanically switched, but switching can also be controlled using a solenoid or an electric motor, or a solenoid valve can also be used. It is.
In this case, the lashing device may electrically restrict energization to the actuator or the solenoid valve.

(Effects of the Invention) As described above, in the present invention, when the corresponding hinge is not switched to a proper state within a predetermined time to suit the desired dumping direction, for example, a hinge abnormality, a hinge switching If a human error occurs during operation or by operating only one switch, the spool of the switching valve can be locked to prevent the cargo box from tilting, making it possible to perform dumping operations with complete certainty. At this time, compared to mechanical lashing via links, etc., there is no effect due to looseness in the link system, and there is no need to change the link system due to changing vehicle models, greatly improving reliability and safety. It is something.

[Brief explanation of drawings]

The drawings illustrate embodiments of the invention.
The figure is a perspective view showing the overall configuration of a three-roll dump truck, FIG. 5 is a front view thereof, FIG. 6 is an electric circuit diagram of the control system, and FIG. 7 is an explanatory diagram showing the positional relationship of the electric motors. 1... Loading box, 3... Hinge shaft, 4... Vehicle chassis, 5... Shaft receiving member, 6... Hook, 7...
...Reed switch, 11...Spool, 13...
Bell crank, 19... Stopper, 21... Hinge switching actuation device.

Claims (1)

[Claims] 1 Front, rear, left and right sides of either the chassis or the bottom of the cargo box 4
A hinge is constructed by providing a hinge shaft at one location, and a shaft receiving portion, a hook, etc. corresponding to the hinge shaft at four locations on the other front, rear, left and right sides, and the tilting operation of the cargo box is performed through a switching operation of a switching valve. In a three-turn dump truck to be controlled, a hinge switching actuating device selectively operates the hinge between a locked state and a released state, a selection switch selecting the hinge corresponding to each tilting direction, and the hinge switching actuating device. an activation switch for activating the switch; and a detection means for detecting whether the switching activation time is within the set time;
A locking device that locks down the switching operation of the switching valve, and a locking device that locks the switching operation of the switching valve, and a locking device that locks the switching operation of the switching valve, and a period during which the hinge switching device is switched to the hinge state in the selected tilting direction by the selection switch or the operating switch, and a switching operation time. A safety device for a three-roll dump truck, characterized in that when a set time has elapsed, switching operation of a switching valve is disabled via a lashing device.