JP3263610B2 - Cab tilt equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is applied to a cab-over vehicle. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an apparatus for tilting a cab with respect to a chassis when performing maintenance work on an engine and other devices arranged under the cab.

[0002]

2. Description of the Related Art There are widely known devices which provide a hinge at a front portion of a cab with a chassis and tilt the cab about the hinge. In such a cab-tilt device, the operator works on the device placed under the cab in a state where the cab is tilted, so that the tilt state of the cab once tilted may be inadvertently returned. Some safety devices are provided so that there is no.

One of them is a link means provided between the cab and the chassis. The link means is composed of two members, one end of the first bracket is rotatably mounted on the undercarriage side, the other end of the second bracket is rotatably mounted on the cab side, The other end and the other end of the second bracket are structured so as to be rotatable around the link axis by a link axis, and when the cab is in the tilt state, the tilt angle between the cab and the chassis is adjusted. A stopper is provided to hold.

There are various types of stoppers, one of which uses a safety pin. This is accomplished by providing a single hole through the two brackets of the linking means in common when the cab is in the tilted state and inserting a sturdy steel safety pin into this hole. The angle of the two brackets around the link axis is not changed, that is, the link means is fixed and the tilt state is maintained. Such a structure is widely used as a highly safe device and a device that gives a sense of security to an operator.

In order to use this device, the driver removes the cab while the driver descends from the cab, and operates the driving means including the electric hydraulic pump and the hydraulic cylinder to slowly set the cab to the tilt state. . This operation is a push button operation of the electric device or an operation of a hydraulic lever that operates a valve of the hydraulic device. When the tilt state is reached, take out the safety pin and insert the safety pin into a hole that passes through both brackets of the link means.
By inserting a pin, this link means is fixed so as not to move.

The safety pin is not used except when the cab is in a tilted state, and when the cab is tilted, the safety pin needs to be at a position close to the operator. Generally, this is configured to be located in a safety pin storage position provided near the link means. In the storage position of this safety pin, simple spring means and hook structure
The safety pin is configured so as not to fall out of its storage position even if there is a degree of vibration that may occur while the vehicle is running. They are chained so that they do not lose if they fall off. Further, when necessary, the worker can reach out the safety pin from the storage position without difficulty by extending his hand in a normal posture.

In such a conventional structure, the drive means for driving the cab to the tilt state and returning the tilt state to the normal state are independent of the use of the safety pin for the link means. That is, the operator operates the driving means,
After confirming that the cab has been tilted by himself, remove the safety pin from its storage position by hand and insert it into the hole for fixing the link means. After completing various operations and inspections in the tilted state, pull out the safety pin from the hole of the link means also by hand, attach it to the storage position and put it in the storage state, and then operate the drive means to operate the cab. To the normal position.

[0008]

Therefore, when the cab is in the tilt state and the safety pin is still inserted in the hole of the link means, the operator forgets the switch and lowers the tilt of the drive means. Is operated, the electric hydraulic device is driven. In this case, excessive force is applied to the safety pin and the link means, and in some cases, the safety pin and the link means may be damaged. If such an erroneous operation is performed, the electric device is forcibly driven, so that battery power may be unnecessarily consumed or the hydraulic device may be damaged. In order to avoid this, an automatic pressure switching valve for automatically releasing the hydraulic pressure to a bypass when the hydraulic pressure becomes abnormally high due to the operation of the electric hydraulic device has been provided.

Further, when dust enters the check valve of the tilt cylinder with a long period of use, the oil pressure in the cylinder gradually decreases, and the cab may slip down after the tilt is completed. This kind of cab slippage can be prevented by the safety pin.However, if the weight of the cab is directly applied to the safety pin and the support by the safety pin may be repeated, You will be damaged. To avoid this, measures have been taken to increase safety, such as passing a safety rod between the cab and chassis to prevent direct contact with the safety pin when the cab is tilted. ing.

The present invention has been made in view of such a background, and has as its object to enhance the safety of a tilt device. An object of the present invention is to provide a cab tilt device provided with an electric circuit that does not react even if an erroneous lowering operation is performed on a scale. SUMMARY OF THE INVENTION It is an object of the present invention to provide a cab tilt device that does not damage the device even if an incorrect cab lowering operation is performed. SUMMARY OF THE INVENTION It is an object of the present invention to provide a cab-tilt device that can raise and correct a cab with a tilt pin inserted into a link means even if the cab slips from a tilt state. SUMMARY OF THE INVENTION An object of the present invention is to provide a cab tilt device that does not waste battery power. An object of the present invention is to provide a cab tilt device that does not require a safety rod (replacement rod). An object of the present invention is to provide an apparatus that eliminates the need for an automatic pressure switching valve that operates when the hydraulic pressure of a driving unit becomes abnormally high.

[0011]

SUMMARY OF THE INVENTION The present invention is directed to a safety and security system.
When the lowering operation is performed by mistake while the pin is inserted into the link means, the operation of the driving means is prohibited, and when the cab slips, the position of the cab is corrected with the safety pin inserted. It is characterized by being able to.

That is, the present invention provides a driving means for tilting a cab relative to a chassis around a hinge provided at a front portion of a cab, and a link means for maintaining a tilt angle between the cab and the chassis in a tilted state. A cab tilt device comprising a safety pin for inhibiting the movement of the link means while maintaining the tilt angle by being inserted into a hole provided in the link means,
A detection switch for electrically detecting that the safety pin has been removed from the hole and in the storage position, and an electric circuit means for inhibiting operation of the driving means when the detection switch has no detection output. It is characterized by the following.

[0013] The driving means may include an electric hydraulic pump, and the electric circuit means may include a means for interrupting a passage of a current supplied to an electric device for driving the hydraulic pump when there is no detection output. Preferably, a key is formed at the tip of the safety pin, a lock is formed in the storage position to match the key, and the detection switch generates the detection output when the key matches the lock. It is desirable to include means.

When the safety pin is removed from the storage position when the cab is tilted and reaches the rising end, the detection switch is turned on and the power supply circuit to the driving means is shut off. Even if an operation of lowering the cab is performed in this state, power is not supplied to the driving means, and the lowering operation of the cab is prohibited.

When the safety pin is returned to the storage position, the detection switch is turned off and the interruption of the power supply circuit to the driving means is released. If a cab lowering operation is performed in this state, power is supplied to the driving means, and the cab is lowered.

If a hydraulic pump driven by an electric motor is used as the driving means, the operation of the hydraulic pump can be prohibited by cutting off the electric circuit to the electric motor.

By forming a key at the tip of the safety pin and forming a lock corresponding to the key at the storage position, it is possible to prevent the electric path from being released by another pin. Furthermore, it is possible to reliably detect that the safety pin has been inserted,
It can be prevented from falling off due to vibration or the like.

Accordingly, when returning the cab in the tilted state to the normal state, even if the lowering operation is performed while the safety pin is inserted into the hole of the link means, the lowering operation of the cab is prohibited. The safety pin can be prevented from being broken or the linking means from being damaged, and even if the cab slips off, it can be corrected while the safety pin is still inserted. Also,
When the cab is in a state where the tilt angle is held by the safety pin, it is possible to prevent the hydraulic pump from being forcibly driven to wastefully consume electric power. In addition, there is no need for a safety rod (replacement rod) used to prevent damage to the safety pin and link means and an automatic pressure switching valve that operates when the hydraulic pressure of the drive means becomes abnormally high. Manufacturing costs can be reduced.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

[0020]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a view showing a configuration of a main part when the cab of the embodiment of the present invention is not in a tilt state, FIG. FIG. 3 is a view showing a configuration of a main part at a certain time, FIG. 3 is a view for explaining insertion of a safety pin into link means when the cab of the embodiment of the present invention is in a tilt state, and FIG. It is a figure showing the tilt state of.

In the embodiment of the present invention, a drive for tilting the cab 1 with respect to the chassis 3 around a first hinge 2 provided on the bottom of the cab 1 and a second hinge 4 provided on the side surface of the chassis 3 as axes. Means 10 and link means 20 for maintaining the tilt angle between cab 1 and chassis 3 in the tilted state
And a safety pin 5 inserted into a hole provided in the link means 20 to inhibit the movement of the cab 1 while maintaining the tilt angle. Further, as a feature of the present invention, a detection switch 6 for electrically detecting that the safety pin 5 is at a predetermined storage position, and the operation of the driving means 10 is prohibited when the detection switch 6 has no detection output. Electrical circuit means. A key 5a is formed at the tip of the safety pin 5 as shown in FIG. 3, a lock corresponding to the key 5a is formed at the storage position, and a detection switch 6 outputs a detection signal when the key 5a matches the lock. Means for generating

The link means 20 includes a first hinge bracket 21 having one end rotatably connected to the first hinge 2, and one end rotatably connected to the second hinge 4. And a second hinge bracket 22 connected thereto. The other end of the first hinge bracket 21 and the other end of the second hinge bracket 22 are rotatably connected. Holes 23 and 24 into which the safety pin 5 is inserted are provided near the connecting portion. First hinge bracket 2 as storage position for safety pin 5
A through hole is formed at a position where the first detection switch 6 is attached.

The electric circuit means includes a cab lock switch 31 which is turned on when the lock of the cab 1 is released, and an off state which is turned off when the cab 1 is tilted and reaches a rising end. Tilt limit switch 32 that is turned on when it is at a position other than the rising end
A tilt switch 33 operated when tilting the cab 1, a tilt relay 34 for opening and closing the circuit between the battery 7 and the electric motor 11, and a lowering of the cab 1 in conjunction with the switching of the pressure oil direction. A changeover switch 35 which is turned on at the time of operation, and a safety relay 36 which opens and closes the circuit by opening and closing the changeover switch 35
And a detection switch 6 for detecting that the safety pin 5 is in the storage position, and a tilt buzzer 37 that sounds when the cab 1 is tilted. A diode 38 is connected between the detection switch 6 and the tilt buzzer 37 so as to be directed forward toward the tilt buzzer 37.

FIG. 5 is a circuit diagram showing the configuration of the driving means and the electric circuit means in the embodiment of the present invention. Each contact position in FIG. 5 is depicted as a contact position when the cab is in a steady position (a state in which a driver can get on and drive).

The driving means 10 includes an electric motor 11 driven by the battery 7 as a power source, a hydraulic pump 13 for supplying oil from an oil tank 12 as pressure oil by a driving force of the electric motor 11, and a supply from the hydraulic pump 13. A tilt cylinder 14 which expands and contracts by the applied pressure oil, a switching valve 15 for switching the direction of the pressure oil supplied to the tilt cylinder 14, and a switching lever 16 for switching the switching valve 15 are included.

As shown in FIG. 4, the tilt cylinder 14 has one end rotatably connected to the second hinge bracket 22 and the other end rotatably connected to the side surface of the chassis 3. Be linked.

Next, the operation of the embodiment of the present invention configured as described above will be described. First, the operation of tilting the cab 1 will be described with reference to FIG.

When the cab lock is released, the cab lock switch 31 is turned on. At this time, tilt
The limit switch 32 is on because the cab 1 is in the normal position, and the changeover switch 35 is set to the changeover valve 15.
Is set to the position where the cab 1 is raised, so that it is in the off state. Therefore, no current is supplied to the exciting coil 36a of the safety relay 36, and the contact is in the ON state. The detection switch 6 is on because the safety pin 5 is in the storage position.

Here, when the tilt switch 33 is pressed and turned on, the current from the battery 7 is supplied to the cab lock switch 31 and the tilt limit switch 3.
2 and the safety relay 36 via the safety relay 36
The contact is supplied to the exciting coil 34a of the relay 34 to turn on the contact. Backflow of current to the detection switch 6 when the tilt switch 33 is pressed is prevented by the diode 38.

As a result, the battery 7 and the electric motor 11 are electrically connected, and the electric motor 11 is started and the hydraulic pump 1 is started.
3 is driven. The drive of the hydraulic pump 13 extends the tilt cylinder 14 and raises the cab 1. During this time, the tilt buzzer 37 receives a current supply from the battery 7 via the cab lock switch 31, the tilt limit switch 32, and the safety relay 36, and sounds.

When the cab 1 reaches the rising end, the tilt limit switch 32 is turned off, and the sound of the tilt buzzer 37 stops. Even if you hold down the tilt switch 33 at the same time,
Since the relay 34 is off, the electric motor 11 is not driven.

When the cab 1 is stopped at the rising end, as shown in FIGS. 2 and 3, the holes 23 and 24 provided in the first hinge bracket 21 and the second hinge bracket 22 match. . The safety pin 5 is withdrawn from the storage position and the matched holes 23 and 24
, The rotation of the first hinge bracket 21 and the second hinge bracket 22 is prohibited, and the link means 20 is fixed while maintaining the tilt angle.
When the safety pin 5 is removed from the storage position, the detection switch 6 is turned off.

Here, when the switching lever 16 is operated to lower the cab 1 in a state where the safety pin 5 is not returned to the storage position, and the switching valve 15 is switched to the lowering side as shown in FIG. The changeover switch 35 is turned on in conjunction with the changeover operation, and the current from the battery 7 is supplied to the exciting coil 36a of the safety relay 36 to turn off the contact. At this time, the detection switch 6 is in the off state because the safety pin 5 is still removed.

In this state, even if the tilt switch 33 is pressed and turned on, the safety relay 36 is off and the detection switch 6 is off. The contact is not supplied to the excitation coil 34a of 34, and the contact is in the off state.
Therefore, no current is supplied from the battery 7 to the electric motor 11, and the cab 1 is at the position of the rising end, and the lowering operation is not performed.

When the safety pin 5 is returned to the storage position, the detection switch 6 is turned on. Here, when the tilt switch 33 is operated and turned on (the state shown in FIG. 7), the current from the battery 7 is supplied to the tilt relay 34 via the cab lock switch 31, the changeover switch 35 and the detection switch 6. It is supplied to the exciting coil 34a. As a result, the contact of the tilt relay 34 is turned on, the battery 7 and the electric motor 11 are electrically connected, the hydraulic pump 13 is driven, the tilt cylinder 14 is operated, and the cab 1 is lowered.

As described above, unless the safety pin 5 is returned to the storage position, even if the tilt switch 33 is erroneously operated to lower the cab 1, the lowering operation is not performed. Therefore, the cab 1 descends while the safety pin 5 is still inserted in the holes 23 and 24 of the first hinge bracket 21 and the second hinge bracket 22, and the safety pin 5 is broken.
Alternatively, damage to the link means 20 can be avoided.

In the drive means 10, when the dust enters the check valve of the tilt cylinder 14 over a long period of use, the hydraulic pressure gradually decreases, and the cab 1 may slip slightly from the rising end. The safety pins 5 are for ultimate safety only, and the continuous support of the cab 1 by the safety pins 5 must be avoided. For this purpose, play is provided at predetermined intervals so that the cab 1 is not in contact with the safety pin 5 when it is at the rising end.

In this state, as shown in FIG. 8, since the cab lock has been released, the cab lock switch 31 is in the ON state, and the changeover switch 35 is in the position where the changeover valve 15 raises the cab 1. It is off because it is set to. Safety relay 3 for that
No current is supplied to the excitation coil 36a of No. 6, and the contact is in the ON state. The detection switch 6 is connected to the safety pin 5
Is off because it is not in the storage position.

Here, if the cab 1 slips down,
The tilt limit switch 32 is turned on,
The current from the battery 7 is the cab lock switch 3
1. It is supplied to the tilt buzzer 37 via the tilt limit switch 32 and the safety relay, and sounds to notify that the cab 1 is starting to descend.

When the tilt switch 33 is depressed by this notification, the current from the battery 7 via the cab lock switch 31, the tilt limit switch 32, the safety relay 36 and the tilt switch 33 is tilted. The contact is supplied to the exciting coil 34a of the relay 34 to turn on the contact.

Thus, the electric current from the battery 7 is supplied to the electric motor 11 via the tilt relay 34, and the hydraulic pump 13 is driven to operate the tilt cylinder 14 to raise the cab 1. When cab 1 reaches the rising end,
Since the hand is released from the tilt switch 33, current is not supplied to the exciting coil 34a of the tilt relay 34, the contact is turned off, and the driving of the motor is stopped.
At the same time, the tilt limit switch 32 is turned off to cut off the current supply to the tilt buzzer 37 and stop the sounding.

As described above, even if the cab 1 slips down, the cab 1 is notified by the sound of the tilt buzzer 37, so that it is possible to take an immediate action, and the safety pin 5 is inserted into the link means 20. The slippage of the cab 1 can be corrected in the state as it is, so that the weight of the cab 1 is not directly added to the safety pin 5 and a safe state is maintained.

A key 5 is attached to the tip of the safety pin 5.
is formed, and a lock corresponding to only this key 5a is formed at the storage position. Therefore, even if another pin is inserted into the storage position, the lock does not match the lock, and even if the cab 1 is to be lowered, the motor 11 is electrically prohibited. Also,
The holes 23 and 24 are also formed with locks that match only the key 5a, and other pins cannot be inserted into the holes.

[0044]

As described above, according to the present invention, when the cab is in the tilt state, the hydraulic device does not react even if the cab is erroneously lowered, so that the cab can be prevented from lowering. Further, when the cab slips off, an alarm is issued and the correction can be made while the safety pin is still inserted in the link means. Accordingly, it is possible to prevent the safety pin and the link means from being subjected to excessive force, and it is possible to prevent the battery from being wastefully consumed by forcibly driving the electric device. Further, a pressure valve that operates when the hydraulic pressure of the safety rod (holding rod) and the drive unit becomes abnormally high can be eliminated, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1A is a diagram showing a configuration of a main part when a cab according to an embodiment of the present invention is not in a tilted state, and FIG.

FIG. 2 is a diagram showing a configuration of a main part when the cab according to the embodiment of the present invention is in a tilt state.

FIG. 3 is a view for explaining insertion of a safety pin into a link means when the cab in the embodiment of the present invention is in a tilt state.

FIG. 4 is a diagram showing a tilt state of a cab in the embodiment of the present invention.

FIG. 5 is a circuit diagram showing a configuration of a driving unit and an electric circuit unit in the embodiment of the present invention.

FIG. 6 is a circuit diagram illustrating a cab raising operation in the embodiment of the present invention.

FIG. 7 is a circuit diagram illustrating a cab lowering operation in the embodiment of the present invention.

FIG. 8 is a view for explaining a correction operation when a safety pin slips off in the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 cab 2 first hinge 3 chassis 4 second hinge 5 safety pin 5a key 6 detection switch 7 battery 10 driving means 11 motor 12 oil tank 13 hydraulic pump 14 tilt cylinder 15 switching valve 16 switching lever 20 linking means 21 First Hinge Bracket 22 Second Hinge Bracket 23, 24 Hole 31 Cab Lock Switch 32 Tilt Limit Switch 33 Tilt Switch 34 Tilt Relay 34a, 36a Excitation Coil 35 Changeover Switch 36 Safety Relay 37 Tilt buzzer 38 Diode

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62D 33/07 B60R 16/02 650

Claims (3)

(57) [Claims] 1. A drive means for tilting a cab with respect to a chassis around a hinge provided at a front portion of a cab, a link means for maintaining a tilt angle between the cab and the chassis in a tilt state, and the link means. A cab tilt device comprising a safety pin for inhibiting the movement of the link means while maintaining the tilt angle by being inserted into a hole provided in the cab, wherein the safety pin is removed from the hole. A cab tilt device comprising: a detection switch for electrically detecting that the storage position is at a position; and an electric circuit means for prohibiting operation of the driving means when the detection switch has no detection output. 2. The driving unit includes an electric hydraulic pump, and the electric circuit unit includes a unit that cuts off a passage of a current supplied to an electric device that drives the hydraulic pump when there is no detection output. The cab tilt device according to claim 1. 3. A key is formed at a tip of the safety pin, and a lock corresponding to the key is formed at the storage position.
2. The cab of claim 1 wherein said detection switch includes means for generating said detection output when said key and said lock match.
Tilt device.