JPH0237643Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an automatic step control device useful for use in a vehicle in which the driver's cab is tilted.

<Prior Art> For vehicles such as trucks with a high riding position, steps for getting on and off the vehicle on the side of the cab are essential. Such steps are automatically extended and retracted when the cab door is opened or closed. The cab is also designed to be tilted forward for inspection and repair of the engine.

<Problems to be solved by the invention> However, since the step control operation and the cab tilt operation are independent, if the cab tilt operation is performed with the step protruding, the protruding step may damage the tire when the cab tilts. An inconvenience will occur.

The present invention was developed in view of the deficiencies of the prior art, and when the step is extended, the cab does not tilt immediately even if the cab is tilted, and the cab tilt starts only after the step is completely retracted. Another object of the present invention is to provide an automatic step control device that operates completely and reliably so that the step does not extend even if the step is extended during tilting.

<Means for solving the problem> The configuration of the automatic step control device according to the present invention that achieves the above purpose is to detect the traveling attitude of the cab and open the step control device in series between the power source and the ground. A cab tilt switch that has a lowering contact connected to the first tilt position detection switch and a rising contact connected to a second tilt position detection switch that opens when tilt completion is detected, and a lowering contact of the cab tilt switch. The cab tilt operation system circuit consists of a series circuit of the cab tilt motor, which is driven when the switch is switched to contact or rising contact, and the tilt position detection switch, which is closed when the step is retracted. a third tilt position detection switch connected to the switch, which is closed when the cab is running;
It has a relay that opens when the cab tilt switch is switched to the upward contact, a solenoid valve that extends the step when energized and retracts it when not energized, and a switching contact for automatic, retraction, and extension. automatic step changeover switch,
The automatic step changeover switch is characterized in that it comprises a step control system circuit which is connected to an automatic contact point of the automatic step changeover switch and is connected in series with a door switch.

<Embodiment> An embodiment of the automatic step control device according to the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of an embodiment of the present invention. FIG. 2 is an overview diagram showing the cab portion of the vehicle with a high riding position. According to an embodiment of the present invention shown in FIG.
In principle, it consists of a parallel circuit of a cab tilt operation system circuit and a step control system circuit between the power supply and ground, and furthermore, the state of each circuit mutually regulates the other circuits.

In FIG. 1, the switching contact 4a connected to the power supply of the cab tilt switch 4 is a falling contact 4b,
It is switched to the rising contact 4c. A tilt position detection switch 5 that detects the cab running posture and opens when the cab is in the running posture is connected to the lowering contact 4b, and a tilt position detection switch 6 that detects the completion of tilt and opens when the cab is tilted is connected to the rising contact 4c. has been done. A step position detection switch 7, which is closed when the riding step is retracted, and a cab tilt motor 8 are connected in series to a common terminal of the tilt position detection switches 5 and 6. The cab tilt motor 8 is connected to the descending side and rising side contacts 4b of the cab tilt switch 4,
4c.

A parallel example of the above-mentioned cab tilt operation system circuit is a step control system circuit connected between a power source and ground. That is, the tilt position detection switch 9 detects the cab running posture and is closed when the cab is in the running posture, and the cab tilt switch 4 connected in series to the tilt position detection switch 9 is opened when the cab tilt switch 4 is switched to the upward side. A switch, for example, a relay 10; an operation control unit, for example, a solenoid valve 11, which is connected to the contacts of the relay 10 and operates to extend the step when energized and retract the step when not energized;
Three switching contacts 1a, 12b, 1 are inserted in series in the solenoid valve 11 for automatic, retraction, and extension.
an automatic step changeover switch 12 having 2c;
Automatic contact 12a of automatic step changeover switch 12
A step control system circuit is constituted by a door switch 13 which is connected in series with the door switch 13 and is opened and closed by opening and closing the door 2 of the cab 1. The opening and closing of the contacts 10a and 10b of the relay 10 is driven by the excitation coil L connected to the rising contact 4c of the cab tilt switch 4. When the cab tilt switch 4 is switched to the rising side, the exciting coil L is energized. The contact circuits 10a and 10b are opened.

The operation of the automatic step control device according to the present invention shown in FIG. 1 will be explained. In FIG. 1, when the cab is in the running position, the cab tilt switch 4 is switched to the lowering contact 4b and the tilt position detection switch 5 is open. On the other hand, in the step control system circuit, the tilt position detection switch 9 is closed;
Since the relay 10 is closed, if the automatic step changeover switch 12 is switched to the automatic contact 12a, the step 3 shown in FIG. 2 will be automatically extended and retracted by opening and closing the door 2. Further, by manually operating the automatic step changeover switch 12, it is possible to extend or retract the step. When the cab tilt switch 4 is first converted to the rising contact 4c while the step is in an extended state by operating the step control system circuit as described above,
The step position detection switch 7 of the cab tilt operation circuit detects that the step is not retracted, and contacts 7a and 7b are open, so even if the cab tilt switch 4 is switched to the upward position, the step position detection switch 7 detects that the step is not retracted. The cab tilt motor 8 does not operate. On the other hand, the excitation coil L of the relay 10 of the step control system circuit is excited, and the contacts 10a of the relay 10,
10b is opened, solenoid valve 11 is de-energized, and step 3 is retracted. Completion of storage in step 3 is detected by step position detection switch 7 of the cab tilt operation system circuit, and contact 7 is detected.
a, 7b are closed, the cab tilt motor 8 starts driving, tilts the cab 1, and when the tilt is completed, opens the tilt position detection switch 6 inserted in the cab tilt switch 4, and at the same time turns on the step control system circuit. Contact 9a of tilt position detection switch 9,
Open 9b. Therefore, the cab will never be tilted when the step 3 is extended. As a result, accidents such as the tire damage due to tilting with the step extended as in the conventional case are completely prevented.

Further, even if the automatic step changeover switch 12 is connected to the overhang contact 12c for some reason during the tilt, the step control system circuit will not overhang the step 3 because the tilt position detector 9 and the relay 10 are open during the tilt.

Next, when lowering the cab from the tilted position to the running position, the cab tilt switch 4 is switched to the lowering contact 4b. The tilt position detection switch 5 is closed because the step is being tilted, and the step position detection switch 7 is closed because the step is retracted.Therefore, the cab tilt motor 8 rotates and the cab moves to the running position. . When the cab's running posture is completed, the tilt position detection switch 5 is opened, the tilt position detection switch 9 of the step control system circuit is closed, the relay 10 is closed, and step 3 is automatically operated by opening and closing the door 2. Become so.

<Effects of the invention> According to the automatic step control device according to the invention,
Even if the cab tilt switch is turned on to the up contact while the step is extended, the step extension will be stopped, the step will be moved to retraction, and the tilt will not start until the step retraction is completed. Further, during tilting, the steps will not protrude no matter how you operate the automatic step changeover switch, cab tilt switch, etc. Therefore, accidents such as damage to tires caused by the protruding step when the cab is tilted are completely prevented. Therefore, the operator can operate without being aware of the mutual relationship between the cab tilt operation and the step operation, which significantly reduces the burden on the operator, and the result is of great practical use.

[Brief explanation of the drawing]

Figure 1 is a circuit configuration diagram of an embodiment of the present invention;
The figure is an overview of the cab of the vehicle. In the drawing, 4 is a cab tilt switch, 5, 6,
9 is a tilt position detection switch, 7 is a step position detection switch, 8 is a cab tilt motor, 10 is a relay, 11 is a solenoid valve, 12 is an automatic step changeover switch, and 13 is a door switch.

Claims (1)

[Scope of utility model registration request] A lowering contact connected to a first tilt position detection switch that opens when the cab's running attitude is detected, which is connected in series between the power supply and the ground, and a second tilt position that opens when the tilt is completed. A cab tilt switch having a rising contact to which a detection switch is connected, a cab tilt motor that is driven when the cab tilt switch is switched to either a falling contact or a rising contact, and a step that is closed when the step is retracted. A cab tilt operation system circuit consisting of a series circuit with a position detection switch, a third tilt position detection switch that is connected in series between the power supply and ground and closes when the cab is running, and the cab tilt switch is raised. A relay that opens when the contact is switched, a solenoid valve that extends the step when energized and retracts the step when not energized, an automatic step changeover switch that has automatic, retracted, and extended switching contacts, and the automatic step An automatic step control device comprising a step control system circuit which is inserted in series with an automatic contact of a changeover switch and grounded, and which is a series circuit with a door switch that closes when opened.