JPH0243788Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is a PTO for automobiles such as garbage collection trucks.
It relates to a switching device.

Conventionally, in a garbage collection vehicle equipped with a loading box 13 and a garbage loading device 14 as shown in FIG. (Power take-off gear device) Normally, it is driven by the power take-off shaft 16 of 1, but the switching lever that engages and disengages the sliding gear of the PTO from the input gear is connected to the cab via the Bowden cable 17 or link mechanism. Operation lever 1 in 18
9, which not only requires a large manual operating force but also places restrictions on the arrangement of Bowden cables or links.

To avoid this, the PTO switching lever was rotated forward and backward using a hydraulic cylinder, and the hydraulic cylinder could not be operated unless the clutch was disengaged, eliminating the need to forget to disengage the clutch when switching the PTO. The idea was put into practice in 1974.
As shown in Japanese Patent No. 166629, since the hydraulic cylinder cannot be expanded or contracted when the clutch is engaged, when the sliding gear is engaged with the input gear, the rotational angle position where the end faces of both gear teeth come into contact with each other is used. If the gear is stopped, the two gears cannot be meshed even if the hydraulic cylinder is operated, and after engaging the clutch and changing the rotation angle position of the input gear, try again to connect the PTO. Must be done. Furthermore, if the pump discharge oil pressure is low, there is a possibility that the input gear and the sliding gear will not mesh completely, and both of these factors together make the PTO connection operation difficult.

The present invention deals with this problem, and is provided between a single-acting power chamber 3 and a vacuum source 4, which normally return the switching lever 2 of the PTO 1 to the off position by a return spring in a PTO of an automobile equipped with a vacuum source. A solenoid valve 6 that is always activated to return is inserted into the conduit 5 at a position where the single-acting power chamber is communicated with the outside air. Insert the open contact 8,
Energizing coil 9 and demagnetizing coil 10 of the keep relay
A switch 11, which closes when the clutch is disengaged, and a changeover switch 12, which is switched from the neutral position to the engaged and disengaged positions, are inserted in series into the operating circuit of the clutch.
Further, the present invention is characterized in that the degaussing coils 10 are made conductive when switching to the disconnected side.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 5. As shown in FIG. 2, the switch 11 is connected to the clutch pedal 20 in the cab 18 so as to be closed when the clutch is completely disengaged by depressing the clutch pedal 20, and is mounted in the cab together with the changeover switch 12. In the figure, members with the same reference numerals as in FIG. 1 indicate corresponding members, and 21 is a shift lever of a traveling transmission.

22 is an exhaust brake device (Fig. 3) mounted on the garbage collection vehicle, which is equipped with a vacuum source (master back) 4 maintained in a vacuum by a vacuum pump 23 driven by the traveling engine, and installed in the engine exhaust pipe 24. A single-acting power chamber 27 with a built-in spring that always urges the opening/closing lever 26 of the exhaust brake valve 25 to return to the valve open position shown in the figure, and a solenoid valve inserted into the conduit 28 between the power chamber 27 and the vacuum source 4. 29
The solenoid valves 29 and 6 are always energized to return to the positions in which the corresponding power chambers are communicated with the outside air via the conduits 30 and 31 and the air cleaner 32, respectively.
In the operating circuit 33 of the switching solenoid 29a of the electromagnetic valve 29, a starter switch 34, an exhaust brake operating switch 35, a relay 36, a switch 37 that closes when the engine stops accelerating, and a switch 38 that closes when the clutch switches are inserted in series. .

39 is a reservoir tank connected to the pipe line 28 between the vacuum source 4 and the solenoid valve 29;
A vacuum sensor 40 attached to the brake valve 9 issues a signal when the vacuum level is such that the brake can be operated, closes the contacts of the relay 36, and enables the solenoid 29a to conduct. When the solenoid 29a is conductive, the solenoid valve 29 connects the power chamber 27 to the vacuum source 4, and the power cylinder operates the exhaust brake valve 2.
5 is closed and the exhaust brake is activated. 41 is a power source, 42 is a check switch, and 43 is a buzzer. An operating circuit 44 for the switching solenoid 6a of the electromagnetic valve 6 and an operating circuit 45 for the coils 9 and 10 are connected to the power source 41 via the starter switch 34. 33
are connected in parallel.

The operating link 46 of the power chamber 3 is an L-shaped member 2b welded and fixed to the lower part of the switching lever 2 via a U-shaped member 2a, as shown in FIGS. 4 and 5.
A stopper bolt 47 is connected to the upper end and engages the lower end of the U-shaped member 2a when the switching lever 2 is rotated to the contact position shown by the chain line in the same figure, and the lower end of the L-shaped member 2b at that time. A limit switch 48 whose cam portion engages and issues a signal is attached to the outer casing of the PTO 1, and a pilot lamp (not shown) inside the cab 17 is lit by the signal issued by the limit switch. Reference numeral 49 indicates a traveling transmission which is interlocked and connected to the engine output shaft via a clutch.

Figure 3 shows a state in which the switching lever 2 is in the off position shown by the solid line in Figure 4, and the PTO sliding gear is disengaged from the input gear. pedal 2
When the switch 11 is closed by depressing the switch 11 and the changeover switch 12 is turned on, the excitation coil 9 becomes conductive and closes the normally open contact 8, which is mechanically held in the closed state and the switch 11, 12 remains open even after opening. Therefore, solenoid 6a
The actuating circuit 44 becomes conductive and the solenoid valve 6 is switched to connect the power chamber 3 to the vacuum source 4, so that the power chamber retracts the actuating link 46 and moves the switching lever 2 to the contact position shown by the chain line in FIG. At the same time as rotating and meshing the sliding gear with the input gear,
Limit switch 48 issues a signal to light the pilot lamp inside the cab. Then, the changeover switch 12 is returned to the neutral position shown.

At this time, if the pilot lamp does not light up because the gear is stopped at a rotational angle position where the end surfaces of both gear teeth are in contact with each other, if the pilot lamp does not light up, loosen the clutch pedal 20 and gradually engage the clutch. When the input gear rotates to a position where the gears can mesh, the switching lever 2 instantly rotates to the contact position by the power chamber 3 to which vacuum pressure is applied, and the two gears quickly mesh and the pilot lamp is activated. lights up.

To cut off power transmission from the PTO, close the switch 11 using the clutch pedal 20 and close the selector switch 12 to the disconnected side.
returns to the normal position, the power chamber 3 communicates with the outside air via the air cleaner 32, the power chamber pushes out the operating link 46 by its own return spring, and moves the switching lever 2 to the off position shown by the solid line in FIG. to separate the sliding gear from the input gear.
Therefore, it is sufficient to return the changeover switch 12 to the neutral position and stop depressing the clutch pedal 20.

According to the present invention, the PTO can be switched on and off instantly using vacuum pressure, and there is no need to forget to disengage the clutch when switching, and the PTO can be engaged and disconnected using the power cylinder.
By being able to perform the connection operation of TO at the same time,
This has the advantage that the PTO can be easily connected regardless of the relative stopping angle positions of the input gear and the sliding gear.

[Brief explanation of drawings]

Figure 1 is a vertical side view of the conventional device, Figure 2 is a vertical side view schematically showing the device of the present invention, Figure 3 is its circuit diagram, and Figures 4 and 5 are a front view and side view of the PTO, respectively. It is a diagram. 15...Hydraulic pump, 16...Power take-off shaft, 1
7... Cab, 22... Exhaust brake device, 23
...Vacuum pump, 32...Air cleaner.

Claims (1)

[Scope of utility model registration request] In an automobile PTO equipped with a vacuum source, the single-acting power chamber 3 is connected to the vacuum source 4 in a conduit 5 between the single-acting power chamber 3 and the vacuum source 4, which normally returns the switching lever 2 of the PTO 1 to the off position by a return spring. A solenoid valve 6 that is normally activated to return is inserted in a position that communicates the power chamber with the outside air, and a normally open contact 8 of a keep relay 7 is inserted into the operating circuit of the solenoid 6a for switching the solenoid valve.
A switch 11, which closes when the clutch is disengaged, and a changeover switch 12, which is switched from the neutral position to the engaged and disengaged positions, are inserted in series into the operating circuit of the excitation coil 9 and demagnetizing coil 10 of the keep relay, When the changeover switch is switched to the on side, the excitation coil 9 is switched on, and when the switch is switched to the disengaged side, the demagnetization coil 1 is switched on.
An automobile PTO switching device characterized in that 0 and 0 are respectively conductive.