JP3101158B2 - Cab-over vehicle step elevating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used for controlling steps provided for getting on and off a cab-over vehicle. INDUSTRIAL APPLICABILITY The present invention is applied to a cab-over type vehicle that performs cab tilt during maintenance.

[0002]

2. Description of the Related Art In recent years, as the size of cab-over type vehicles for cargo and other vehicles has increased, and the number of female drivers driving cab-over type vehicles has increased, the step of getting on and off outside when getting in and out of the cab has been carried out. Vehicles equipped with are becoming popular. If this step for getting on and off is installed at a convenient position when getting on and off, the step will project to a position lower than the height of the chassis of the vehicle,
This is inconvenient for driving a car. For this reason, a device for displacing the step for getting on and off between a position in use and a position in traveling using an actuator has been developed and used (for example, Japanese Utility Model Publication No. 2-37643).

[0003] In a conventional apparatus, a step for getting on and off is provided in a cab-over vehicle so that the cab is stored in conjunction with the cab when the cab is tilted (Japanese Utility Model Publication No. 60-1885).
No. 4) and a structure interlocked with a door for getting on and off a driver's seat (Japanese Utility Model Publication No. 15716/1995) are known.

[0004] Regarding these conventional structures, whether the actuator for driving the step for getting on or off is an electric type or a hydraulic drive type, a unique device is used for driving the step for getting on and off. Have. Even with a drive device for changing the position of the step for getting on and off, considering the safety and reliability of the device, it can be effectively driven even under a load several times the weight of a person. In addition to the fact that the device is required to be designed in a high speed, the device becomes considerably expensive when using the hydraulic circuit or the electric circuit, and the number of parts mounted on the automobile increases, and the vehicle weight increases. .

In a prior application (Japanese Patent Application No. 6-75076, unpublished at the time of filing of the present application) in which the applicant of the present invention is one of the joint applicants, a new device for controlling a step for getting on and off using hydraulic pressure for cab tilt is disclosed. Proposed. This is characterized in that a switching valve for switching the output hydraulic pressure of the hydraulic pressure generator for cab tilt to a hydraulic circuit for step displacement is provided.

[0006]

The inventors of the present invention have conducted many tests on the technology disclosed in the prior application. As a result, it was confirmed that it is possible to effectively utilize the hydraulic pressure generating device for Kyabuchiruto hydraulic for step displacement, it requires a large number of parts for the switching control of the hydraulic circuit, the power supply of the control circuit Some improvements were found, such as insufficient measures against obstacles and the like, the step-elevating device can be conveniently operated when the driver gets off, but the operation is inconvenient when the driver tries to get on from outside. Was.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in such a background, and has as its object to provide an inexpensive hydraulic circuit . An object of the present invention is to simplify a hydraulic circuit for raising and lowering a step. An object of the present invention is to provide an inexpensive step lifting / lowering device using hydraulic pressure. SUMMARY OF THE INVENTION It is an object of the present invention to provide a step elevating device that is controlled to be on the safe side even when the power supply of the control circuit is stopped. An object of the present invention is to provide a device capable of appropriately operating a step elevating device even when a driver intends to get on a vehicle.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an apparatus for raising and lowering a step provided for getting on and off a cab-over vehicle, comprising: a first hydraulic circuit for supplying a hydraulic pressure to a first cylinder for cab tilt; A second hydraulic circuit that supplies hydraulic pressure to a second cylinder that moves up and down a step provided at the entrance / exit, and a hydraulic pump that supplies hydraulic pressure to the first hydraulic circuit and the second hydraulic circuit in common; One hydraulic circuit includes a first opening / closing solenoid valve that opens and closes a hydraulic passage between the first cylinder and a first switching solenoid valve that switches a hydraulic pressure supply direction of the first cylinder. A second opening / closing solenoid valve that opens and closes a hydraulic passage between the second cylinder and a second switching solenoid valve that switches a hydraulic pressure supply direction of the second cylinder. Characterized by comprising a single control circuit Gosuru.

The first opening / closing solenoid valve and the second opening / closing solenoid valve respectively block a hydraulic passage in an energized state (ON state) and conduct a hydraulic passage in a non-excited state (OFF state). The valve supplies hydraulic pressure in the direction of tilting the cab in the excited state, supplies hydraulic pressure in the direction of returning the cab in the non-excited state, and the second switching solenoid valve supplies hydraulic pressure in the direction of lowering the step in the excited state. It is desirable to supply hydraulic pressure in the direction of raising the step in the excited state.

The operation inputs include a manually operated tilt / step changeover switch, a manually operated tilt up / down instruction switch, a load switch operated by a load on a step, an upper limit switch of the step, and A lower limit switch, wherein the control circuit controls the first opening / closing solenoid valve and the second opening / closing solenoid valve according to a setting position of the tilt / step changeover switch, and sets the tilt up / down instruction switch. Means for controlling the first switching solenoid valve in accordance with a position; means for controlling the second switching solenoid valve in accordance with the setting position of the load switch and the setting state of the two limit switches; Means for prohibiting all exciting currents supplied to the four solenoid valves when in the state. Mukoto is desirable.

[0011] Further, a key that is portable and generates a radio signal is provided, and the control circuit includes means for receiving the radio signal, and the second opening / closing electromagnetic circuit unless a specific signal arrives at the receiving means. Means for setting a valve to a hydraulic shutoff state, wherein the operation input includes an opening sensor output of an entrance door provided with the step, and the control circuit uses the opening sensor to allow a person to enter or exit the entrance door. It is desirable to include means for enabling the second hydraulic circuit only when it is as open as possible.

[0012]

When the control circuit receives an operation input, the hydraulic pump is driven to supply hydraulic pressure to the first hydraulic circuit for supplying hydraulic pressure to the first cylinder for cab tilt and to the second cylinder for raising and lowering a step provided at the entrance / exit port. The hydraulic pressure is commonly supplied from one hydraulic pump to the second hydraulic circuit. In the first hydraulic circuit, the first opening / closing solenoid valve opens and closes the hydraulic passage of the first cylinder, and the first switching solenoid valve switches the hydraulic pressure supply direction of the first cylinder, that is, up and down of the cab tilt. On the other hand, in the second hydraulic circuit, the second opening / closing solenoid valve opens and closes the hydraulic passage of the second cylinder, and the second switching solenoid valve switches the hydraulic pressure supply direction of the second cylinder, that is, up and down steps.

The first on-off solenoid valve and the second on-off solenoid valve are:
The hydraulic passage is shut off in the excited state (ON state), and the hydraulic passage is conducted in the non-excited state (OFF state). Also,
The first switching solenoid valve supplies hydraulic pressure in a direction to tilt the cab in an excited state (on state), and a non-excited state (off state).
To supply the hydraulic pressure in the direction to return the cab, the second switching solenoid valve supplies the hydraulic pressure in the direction to lower the step in the excited state (ON state), and the hydraulic pressure in the direction to raise the step in the non-excited state (OFF state). Supply.

Operation inputs to the control circuit include a manually operated tilt / step change switch, a manually operated tilt up / down instruction switch, a load switch operated by a load on the step, an upper limit switch of the step, and a step upper limit switch. From the lower limit switch. The control circuit controls the first opening / closing solenoid valve and the second opening / closing solenoid valve according to the setting position of the tilt / step changeover switch, controls the first switching solenoid valve according to the setting position of the tilt up / down instruction switch, and sets the load switch. position,
The second switching solenoid valve is controlled according to the setting state of the upper limit switch and the setting state of the lower limit switch. This prevents only the steps from moving before the person gets on.

When the key switch of the vehicle is in an off state, the control circuit supplies an exciting current to be supplied to the first opening / closing solenoid valve, the first switching solenoid valve, the second switching solenoid valve, and the second switching solenoid valve. All are prohibited. Therefore, up and down of the cab and up and down of the step are not performed in a state where the driver is absent.

When a radio signal is generated from the portable key, the control circuit receives the radio signal and sets the second on-off solenoid valve to the hydraulic shutoff state unless a specific signal arrives.

The operation input also includes an output of an opening sensor of a door provided with a step, and the control circuit detects that the opening sensor is open to the extent that a person can get on and off the door. Sometimes we activate the second hydraulic circuit,
The steps do not go up or down without any people coming and going.

[0018] Thus, when the control circuit is in the configuration can perform all control operations required to step passenger, it is possible to reduce the manufacturing cost and Turkey can simplify the hydraulic circuit It can be controlled to the safe side when the power supply of the control circuit is stopped. When the driver tries to get on the vehicle, the driver can remotely perform the step-down operation without touching the vehicle from outside.

[0019]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a hydraulic system and a main part of a control system according to an embodiment of the present invention, FIG. 2 is a diagram showing operation inputs and control outputs of a control circuit in the embodiment of the present invention, and FIG. FIG. 4 is a partial cross-sectional front view showing the mounting state of the step, and FIG. 4 is a partial cross-sectional side view showing the mounting state of the step in the embodiment of the present invention.

The embodiment of the present invention comprises a first hydraulic circuit 10 for supplying hydraulic pressure to the first cylinder 1 for cab tilt, and a second hydraulic circuit for supplying hydraulic pressure to the second cylinder 3 for raising and lowering the step 2 provided at the entrance / exit. A hydraulic circuit 20, a hydraulic pump 4 for supplying hydraulic pressure to the first hydraulic circuit 10 and the second hydraulic circuit 20, an electric motor 5 for driving the hydraulic pump 4, and an oil tank 8. In the hydraulic circuit 10,
A first opening / closing solenoid valve 11 for opening and closing a hydraulic passage between the first cylinder 1 and a first switching solenoid valve 12 for switching the oil pressure supply direction of the first cylinder 1;
A second opening / closing solenoid valve 21 for opening and closing a hydraulic passage between the second cylinder 3 and a second switching solenoid valve 22 for switching a hydraulic pressure supply direction of the second cylinder. It includes one control circuit 6 for controlling the opening / closing solenoid valve 11, the first switching solenoid valve 12, the second switching solenoid valve 21, and the second switching solenoid valve 22. A check valve 13 for preventing pressure backflow is disposed in a pipe connecting the hydraulic pump 4 to the first hydraulic circuit 10, the second hydraulic circuit 20, and the oil tank 8.

Each of the first opening / closing solenoid valve 11 and the second opening / closing solenoid valve 21 shuts off the hydraulic passage in the excited state (ON state) and conducts the hydraulic passage in the non-excited state (OFF state).
The first switching solenoid valve 12 supplies hydraulic pressure in a direction to tilt the cab in an excited state (ON state), and supplies hydraulic pressure in a direction to return the cab in a non-excited state (OFF state). The second switching solenoid valve 22 supplies the hydraulic pressure in the direction of decreasing the step in the excited state (ON state), and supplies the hydraulic pressure in the direction of increasing the step in the non-excited state (OFF state).

As shown in FIG. 2, the operation inputs include a manually operated tilt / step changeover switch 31, a manually operated tilt up / down instruction switch 32, and a load switch 33 operated by the load on step 2. , The upper limit switch 34 and the lower limit
A control circuit for controlling the first opening / closing solenoid valve 11 and the second opening / closing solenoid valve 21 in accordance with the set position of the tilt / step switch 31;
Means for controlling the first switching solenoid valve 12 in accordance with the setting position of the tilt up / down instruction switch 32;
Means for controlling the second switching solenoid valve 22 in accordance with the set position of the upper limit switch 34 and the setting state of the lower limit switch 35, and supply to the four solenoid valves when the key switch 36 of the vehicle is in the off state. Means for prohibiting all exciting currents.

Further, a key 7 which is portable and generates a radio signal is provided. The control circuit 6 includes means for receiving the radio signal, and a second opening / closing solenoid valve unless a specific signal arrives at the receiving means. Means for shutting off the hydraulic pressure of the door 21. The operation input includes the output of the opening / closing door opening sensor 37 provided with step 2, and the control circuit 6 controls the opening / closing door 37 by using the opening sensor 37. Means for enabling the second hydraulic circuit 20 only when it is open enough for a person to get on and off is included.

In addition to the operation input described above, the control circuit 6 has a cab at the lower end and a cab lock switch 41 which is turned on when a mechanical lock is applied, and when the cab is at the upper end. The cab stopper switch 42 is turned on when the vehicle is opened, the door switches 43 _L and 43 _R are turned on when the left and right doors are opened, and the neutral switch is turned on when the transmission is in the neutral position. 44, a parking switch 45 that is turned on when parking, and a door lock switch 46 that is turned on when the door is locked. A detection output from the vehicle speed sensor 9 is input, and is connected to an antenna 47 that receives a radio signal from the key 7.

A tilt buzzer 51 that blows during the tilt operation of the cab, a tilt indicator lamp 52 that is disposed outside and lights up when the tilt and up / down instruction switch 32 is operated, and when the step 2 is raised and lowered. Output is made to the step operation alarm buzzer 53 that sounds and door lock actuators 54 _R and 54 _L that perform door lock and release.

[0026] Key 7, and the door lock buttons 7a and the lock release button 7b inputting instructions for causing the door lock and unlock the door lock actuator 54 _R, 54 _L, up and down steps 2 Step up instruction button 7c for inputting operation instructions
And a step-down instruction button 7d.

Next, various operations in the embodiment of the present invention configured as described above will be described. First, the step lowering operation will be described. FIG. 5 is a diagram for explaining the step lowering operation in the embodiment of the present invention, and FIG. 6 is a flowchart showing the flow of the step lowering operation by the control circuit in the embodiment of the present invention.

When the vehicle stops and the tilt / step changeover switch 31 is switched to the stepping operation side, the control circuit 6 outputs "0" of the vehicle speed sensor 9, "ON" of the parking switch 45, and neutral switch. "on" 44, and enter the "off" of the key switch 36, to check whether the door switch 43 _R or 43 _L is in the on state. Door switch 43 _R or 43
If any of _L is in the ON state, it is checked whether or not the opening sensor 37 provided in the door is in the ON state. If it is in the ON state, it is confirmed whether or not there has been a descending instruction of step 2 from the step descending instruction button 7d of the key 7.

If there is a descending instruction in step 2, the timer is operated, and it is confirmed again whether or not a step descending signal has been input. If there is a descending instruction, the timer is stopped after elapse of 2 seconds. It is confirmed whether or not two step down signals have been input. This operation is performed for the purpose of confirming, for safety, whether or not the input of the step-down signal has been performed reliably.

Here, when a person gets on step 2, the load sensor 33 is turned on, and when the control circuit 6 receives this output, the first open / close solenoid valve 11 is turned on and the hydraulic pump 4 The pipeline for raising the first cylinder 1 for cab tilt is shut off, and the first switching solenoid valve 12 is turned off so that the hydraulic pressure from the hydraulic pump 4 is supplied to the side for lowering the first cylinder 1. Therefore, even if the first opening / closing solenoid valve 11 becomes abnormal and becomes conductive, the hydraulic pressure is supplied to the side for lowering the cab, so that safety is ensured.

Subsequently, the second switching solenoid valve 22 is turned off so that the hydraulic pressure from the hydraulic pump 4 is supplied to the side for lowering the second cylinder 3 for stepping up and down. Is turned off to make the conduit to the second cylinder 3 conductive. Here, power is supplied to the electric motor 5 to drive the hydraulic pump 4. The hydraulic pressure from the hydraulic pump 4 is supplied to the lowering side of the second cylinder 3 via the second switching solenoid valve 22 and the second opening / closing solenoid valve 21 as shown by the arrow in FIG. At the same time, the step operation alarm buzzer 53 is sounded to notify that step 2 is descending and to operate the timer.

When step 2 reaches the lower end and contacts the lower limit switch 35 to be turned on,
The power supply to the electric motor 5 is cut off, and the drive of the hydraulic pump 4 is stopped. Rowa limit switch 35 when the timer not turn on condition has elapsed the predetermined time t ₀ seconds such failure, likewise stops driving the hydraulic pump 4 to interrupt the power supply to the motor 5. As a result, step 2 is in a descending state.

When the door is locked after step 2 is lowered and the vehicle is dismounted, the door is locked according to the flow of the door lock operation shown in FIG. Even when the key switch is turned off, the voltage is always applied from the backup power supply to the control circuit 7. Therefore, when the door lock button 7 a of the key 7 is pressed from outside the vehicle, the control circuit 6 transmits the signal to the antenna 47. And confirms whether the instruction is a door lock instruction.

In the case of a door lock instruction, the transmitted signal code is compared with a pre-recorded code to confirm whether or not the code matches. If they coincide drives the door lock actuator 54 _L and 54 _R to the door lock state.

Next, the operation of unlocking the door from outside the vehicle will be described. FIG. 8 shows a door and door according to the embodiment of the present invention.
It is a flowchart which shows the flow of an unlock operation.

When the lock release button 7b of the key 7 is pressed from outside the vehicle, the control circuit 6 receives the signal via the antenna 47 and confirms whether or not it is an instruction to unlock the door. If the instruction is to unlock the door, the code of the transmitted signal is checked against a pre-recorded code to check whether they match. If they coincide drives the door lock actuators 54 _R and 54 _L to the door unlocked.

Here, a description will be given of the ascending operation in step 2 when the user gets on the vehicle after the door is unlocked. FIG. 9 is a diagram for explaining the step-up operation in the embodiment of the present invention, and FIG. 10 is a flowchart showing the flow of the step-up operation by the control circuit in the embodiment of the present invention.

When the step-up instruction button 7c of the key 7 is pressed, the control circuit 6 receives the instruction signal via the antenna 47, and determines whether the door is unlocked by the key 7 as described above. Alternatively, it is checked whether the unlocked state has been established manually. If the door is in the unlocked state, it is checked whether the neutral switch 44, the parking switch 45, and the opening degree sensor 37 are in the ON state and there is no output from the vehicle speed sensor 9 (vehicle speed is zero). I do. Next, it is checked whether or not the instruction from the key 7 is to raise step 2, and if it is the raising instruction of step 2, the timer is operated and it is checked again whether or not the step raising signal is input. If there is a rising instruction, the timer is stopped after two seconds have elapsed, and it is confirmed whether or not two step rising signals have been input within the two seconds. This operation is performed in order to securely confirm whether or not the input of the ascending signal of the step has been performed surely as in the case of the step-down operation.

Here, it is confirmed whether or not a person is on the step 2 by turning on / off the load switch 33.

If the load switch 33 is in the ON state, it is determined that a person is riding on the vehicle, and the first opening / closing solenoid valve 11 is turned ON to disconnect the line from the hydraulic pump 4 to the first cylinder 1 for cab tilt. Then, the first switching solenoid valve 12
Is switched off so that the hydraulic pressure from the hydraulic pump 4 is supplied in a direction to lower the first cylinder 1. Further, the second switching solenoid valve 22 is turned on so that the hydraulic pressure from the hydraulic pump 4 is supplied to the side for raising the second cylinder 3 for stepping up and down.
1 is turned off to establish a conductive state so that the hydraulic pressure from the hydraulic pump 4 raises the second cylinder 3.

Here, the electric power is supplied to the electric motor 5 to drive the hydraulic pump 4, and to the second cylinder 3 via the second switching solenoid valve 22 and the second opening / closing solenoid valve 21 as shown by arrows in FIG. 9. Supply hydraulic pressure. The second cylinder 3 is extended by the supply of the hydraulic pressure, and the step 2 is raised. At the same time as the supply of the hydraulic pressure is started, the step operation alarm buzzer 53 is sounded to notify that step 2 is being raised and to activate the timer.

Although the hydraulic pressure from the hydraulic pump 4 is also supplied to the first switching electromagnetic valve 12 side, no hydraulic pressure is supplied to the first cylinder 1 because the first opening / closing electromagnetic valve 11 is in a shut-off state.
When an abnormality occurs in the first opening / closing solenoid valve 11 and the conductive state is established, the hydraulic pressure is supplied to the first cylinder 1. However, since the hydraulic pressure is supplied to the side where the first cylinder 1 is lowered, the cab rises. That is prevented.

When step 2 reaches the rising end and comes into contact with the upper limit switch 34, it is turned on. When the output is received, the power supply to the electric motor 5 is cut off and the drive of the hydraulic pump 4 is stopped. Further, when the upper limit switch 34 has exceeded the predetermined time t ₁ while not turned on in malfunction driving the power supply is cut off the hydraulic pump 4 to the electric motor 5 is stopped by the timer. As a result, step 2 is in an ascending state.

When the door lock button 7a of the key 7 is depressed when the door is locked by ascending step 2 in this manner, the control circuit 6 receives the instruction signal as shown in FIG. it is confirmed whether or not the door locking instruction door lock actuator 54 _L, 54 _R
To lock the door.

Also, as shown in FIG.
When the door 6 is turned on and the door lock knob on the driver's seat side is depressed to lock the door, the door lock switch 46 is turned on in conjunction with this, and the output of the control circuit 6 is received by the control circuit 6. Door lock actuator 54
Drive the _R to lock the door. Further, as shown in FIG. 13, when the vehicle is started without the door being locked at the time of getting on the vehicle, the control circuit 6 turns on the door lock when the detection output from the vehicle speed sensor 9 exceeds a predetermined value. it is also possible to lock automatically the door by driving the actuator 54 _L, 54 _R. In order to further increase the safety of the step-up / down operation, the operation of the step-up button 7c and the step-down instruction button 7d may be pressed several times within a certain time, for example, twice in two seconds.

Next, the cab raising operation in the embodiment of the present invention will be described. FIG. 14 is a diagram for explaining the cab raising operation in the embodiment of the present invention, and FIG. 15 is a flowchart showing the flow of the cab raising operation by the control circuit in the embodiment of the present invention.

The control circuit 6 includes a key switch 36, a parking switch 45, and a neutral switch 44.
Is turned on, and if it is on, it is checked whether the tilt / step switch 31 is operated to the tilt side. If it is operated on the tilt side, it is confirmed whether the tilt up / down instruction switch 32 is operated on the ascending side, and if it is operated on the ascending side, the tilt buzzer 51 is sounded to notify the execution of the cab elevating operation. I do.

First, the second opening / closing solenoid valve 21 is turned on to shut off the line to the second cylinder 3, and the second switching solenoid valve 22 is turned off to turn the line on the supply side of the hydraulic pump 4 into the second position. Switching is performed so that the two cylinders 3 are connected to the lowering side. Next, the first switching solenoid valve 12 is turned on,
Further, the first opening / closing solenoid valve 11 is turned off, and the conduit to the first cylinder 1 is brought into a conducting state.

Here, the lock release lever is manually pulled to turn on the cab lock switch 41 to check whether or not the cab lock has been released. If the cab lock has been released, power is supplied to the electric motor 5. The hydraulic pump 4 is supplied to drive the hydraulic pump 4. At this time, the tilt display lamp 52 is turned on to notify that the cab is being raised.

By driving the hydraulic pump 4, hydraulic pressure is supplied from the first switching solenoid valve 12 to the rising side of the first cylinder 1 through the first opening / closing solenoid valve 11, and the rod 1a is raised to tilt the cab. From the hydraulic pump 4, the second switching solenoid valve 22
The hydraulic pressure is also supplied to the side of the second cylinder 3 that lowers the step 2 through the step. However, since the second opening / closing solenoid valve 21 is in the shut-off state, no hydraulic oil is supplied to the second cylinder 3 and the step 2 is not performed.

When the tilt up / down instruction stitch 32 is switched to the neutral position in the middle of the ascending operation, the ascent operation is stopped at that position, and when the stitch 32 is switched to the descending position, the operation shifts to the descending operation. When the ascending operation is continued and the cab comes into contact with the cab stopper switch 42, the cab is turned on to notify that the cab has reached the ascending end. Thereby, the control circuit 6 shuts off the power supply to the electric motor 5 and stops the supply of the hydraulic pressure from the hydraulic pump 4 to the first cylinder 1. At the same time, the sounding of the tilt buzzer 51 is stopped, and it is confirmed whether or not the tilt up / down instruction switch 32 has been turned off (neutral position). If the tilt up / down switch 32 has been turned off, the tilt indicator lamp 52 is turned off.

Since the check valve 13 is disposed in the pipeline connecting the hydraulic pump 4 with the first cylinder 1, the second cylinder 3, and the oil tank 8, the reverse flow of the hydraulic pressure for each pipeline is provided. Is prevented.

Next, the cab lowering operation will be described.
FIG. 16 is a diagram for explaining the cab lowering operation in the embodiment of the present invention, and FIG. 17 is a flowchart showing the flow of the cab lowering operation by the control circuit in the embodiment of the present invention.

The control circuit 6 includes a key switch 36, a parking switch 45, and a neutral switch 4.
It is checked whether or not 4 is in the on state, and if it is in the on state, it is checked whether or not the tilt / step switch 31 has been operated to the tilt side. If it is operated on the tilt side, it is checked whether the tilt up / down instruction switch 32 is operated on the descending side. If it is operated on the descending side, the tilt buzzer 51 is blown to execute the cab lowering operation. Notice.

First, the second opening / closing solenoid valve 21 is turned on to shut off the line to the second cylinder 3, and the second switching solenoid valve 22 is turned off to turn off the line on the supply side of the hydraulic pump 4. Switching is performed so that the two cylinders 3 are connected to the lowering side. Next, the first switching solenoid valve 12 is turned off,
Further, the first opening / closing solenoid valve 11 is turned off, and the conduit to the first cylinder 1 is brought into a conducting state.

Here, the ON state of the cab stopper switch 42 indicating that the cab is at the rising end is confirmed. If the cab stopper switch 42 is in the ON state, it is confirmed whether or not the tilt up / down instruction switch 32 has been switched to the down side. . If it has been switched to the descending side, power is supplied to the electric motor 5 to drive the hydraulic pump 4. At this time, the tilt display lamp 52 is turned on to notify that the cab is being lowered.

By driving the hydraulic pump 4, oil pressure is supplied from the first switching electromagnetic valve 12 to the lowering side of the first cylinder 1 via the first opening / closing electromagnetic valve, and the rod 1a is lowered to return the cab from the tilt state. The hydraulic pressure is also supplied from the hydraulic pump 4 to the side for lowering the step 2 of the second cylinder 3 via the second switching electromagnetic valve 22 in the same manner as in the rising operation, but the second opening / closing electromagnetic valve 21 is shut off. Therefore, the hydraulic pressure is not supplied to the second cylinder 3 and the raising / lowering operation of Step 2 is not performed.

When the cab finishes descending, the lock release lever is returned to indicate that the cab has been locked.
The off state of the switch 41 is confirmed, and if it is off, the power supply to the electric motor 5 is cut off and the supply of the hydraulic pressure from the hydraulic pump 4 to the first cylinder 1 is stopped. At the same time, the sounding of the tilt buzzer 51 is stopped, and it is confirmed whether or not the tilt up / down instruction switch 32 has been turned off (neutral position). If the tilt up / down switch 32 has been turned off, the tilt indicator lamp 52 is turned off.

[0059]

As described above, according to the present invention, the hydraulic circuit can be simplified and the rotational direction of the motor for generating hydraulic pressure can be limited to one direction, so that the manufacturing cost can be reduced. In addition, when the power supply of the control circuit is stopped, it can be controlled to the safe side, and when the driver tries to get on the vehicle, the driver can perform the step-down operation from outside the vehicle. effective.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main part of a hydraulic system and a control system according to an embodiment of the present invention.

FIG. 2 is a diagram showing operation inputs and control outputs of a control circuit according to the embodiment of the present invention.

FIG. 3 is a partial cross-sectional front view showing an attached state of a step in the embodiment of the present invention.

FIG. 4 is a partial cross-sectional side view showing an attached state of a step in the embodiment of the present invention.

FIG. 5 is a view for explaining a step lowering operation in the embodiment of the present invention.

FIG. 6 is a flowchart showing a flow of a step lowering operation by the control circuit in the embodiment of the present invention.

FIG. 7 is a flowchart showing a flow of a door lock operation in the embodiment of the present invention.

FIG. 8 is a flowchart showing a flow of a door unlocking operation in the embodiment of the present invention.

FIG. 9 is a diagram illustrating a step-up operation in the embodiment of the present invention.

FIG. 10 is a flowchart showing the flow of a step-up operation by the control circuit according to the embodiment of the present invention.

FIG. 11 is a flowchart showing an example of a door lock operation in the embodiment of the present invention.

FIG. 12 is a flowchart showing another example of the door locking operation in the embodiment of the present invention.

FIG. 13 is a flowchart showing still another example of the door locking operation in the embodiment of the present invention.

FIG. 14 is a view for explaining a cab raising operation in the embodiment of the present invention.

FIG. 15 is a flowchart illustrating a cab raising operation by the control circuit according to the embodiment of the present invention.

FIG. 16 is a diagram for explaining a cab lowering operation in the embodiment of the present invention.

FIG. 17 is a flowchart illustrating a cab raising operation by the control circuit according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 First cylinder 1a Rod 2 Step 2a Arm 3 Second cylinder 4 Hydraulic pump 5 Electric motor 6 Control circuit 7 Key 7a Door lock button 7b Unlock button 7c Step up instruction button 7d Step down instruction button 8 Oil tank 9 Vehicle speed sensor 10 First hydraulic circuit 11 First opening / closing solenoid valve 12 First switching solenoid valve 13 Check valve 20 Second hydraulic circuit 21 Second opening / closing solenoid valve 22 Second switching solenoid valve 31 Tilt / step switching switch 32 Tilt up / down instruction switch 33 Load switch 34 upper limit switch 35 Rowa limit switch 36 key switch 37 opening sensor 41 cab switch 42 cab stopper switch 43 _L, 43 _R door switch 44 neutral switch 45 parking Su Pitch 46 door lock switch 47 antenna 51 tilt buzzer 52 tilt display lamp 53 step operation warning buzzer 54 _L, 54 _R door lock actuator

Claims (3)

(57) [Claims] 1. A hydraulic pressure is applied to a first cylinder for cab tilt.
First hydraulic circuit to be supplied and steps provided at the entrance
The second hydraulic circuit that supplies hydraulic pressure to the second cylinder that raises and lowers
And common to this first hydraulic circuit and this second hydraulic circuit
And a hydraulic pump for supplying hydraulic pressure to the first hydraulic circuit.
The first on-off solenoid valve that opens and closes the passage, and the oil in this first cylinder
A first switching solenoid valve for switching a pressure supply direction, and a hydraulic communication between the second hydraulic circuit and the second cylinder.
Solenoid valve for opening and closing the passage, and oil for the second cylinder
A second switching solenoid valve for switching a pressure supply direction, wherein one of the four solenoid valves is controlled according to an operation input.
Control circuit, The first on-off solenoid valve and the second on-off solenoid valve,
The hydraulic passage is shut off in the excited state, and the hydraulic passage is
And the first switching solenoid valve turns on the cab in the excited state.
Supply hydraulic pressure in the direction of tilt and operate the cab in the non-excited state.
Supply hydraulic pressure in the return direction, and the second switching solenoid valve is
Supply hydraulic pressure in the direction to lower the step in the non-excited state
Supply hydraulic pressure in the direction to raise the step, In the control circuit, the key switch of the vehicle is in an off state
Sometimes the exciting current supplied to the four solenoid valves is all
Including means for stopping A cab-over vehicle
Tep lifting device. (2)The operation input is a manually operated tilt
・ Step switch and tilt up / down manually operated
Indication switch and the load that is activated by the load on the step
Switch and step upper limit switch and
And lower limit switch, The control circuit is configured to control the tilt / step changeover switch.
The first opening / closing solenoid valve and the second
Means for controlling the two-way solenoid valve;
The first switching solenoid valve is controlled according to the set position of the switch.
Control means, the setting position of the load switch and two
According to the setting state of the limit switch of the second
Means for controlling the switching solenoid valve. The cap according to claim 1
Step-up / down device for a bootover vehicle. (3)Apply hydraulic pressure to the first cylinder for cab tilt
First hydraulic circuit to be supplied and steps provided at the entrance
The second hydraulic circuit that supplies hydraulic pressure to the second cylinder that raises and lowers
And common to this first hydraulic circuit and this second hydraulic circuit
And a hydraulic pump for supplying hydraulic pressure to the Hydraulic communication between the first hydraulic circuit and the first cylinder is performed.
The first on-off solenoid valve that opens and closes the passage, and the oil in this first cylinder
A first switching solenoid valve for switching the pressure supply direction, Hydraulic communication between the second hydraulic circuit and the second cylinder is performed.
Solenoid valve for opening and closing the passage, and oil for the second cylinder
A second switching solenoid valve for switching the pressure supply direction, One to control the four solenoid valves according to the operation input
Equipped with a control circuit of A key that is portable and generates a radio signal is provided.
Means for receiving this radio signal,
Unless the specific signal arrives at the second opening / closing electromagnetic
Means for shutting off the hydraulic pressure of the valve. Characterized by
Step-up / down device for cab-over vehicles.