JPH0728028Y2 - Loading control device for garbage trucks - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a loading control device for a refuse collecting vehicle, and particularly a PTO hydraulic pump for supplying pressure oil to a loading hydraulic circuit of the loading device.
The present invention relates to a loading control device for a refuse collecting vehicle that is configured to be driven by a running engine via a (power take-out device) and that includes an electric circuit for controlling a loading hydraulic circuit.

[Conventional technology]

A garbage collection vehicle in which a tailgate having a built-in garbage loading device is arranged at the rear of the garbage storage box is widely known. The dust loading device of this type of dust truck normally operates with a hydraulic actuator, which has
Pressure oil is supplied from a hydraulic pump driven by the rotation of a traveling engine, and the traveling engine is accelerated by depressing an accelerator pedal.

Further, the traveling engine and the hydraulic pump are connected via a PTO, and the rotation of the traveling engine is transmitted to the hydraulic pump when the PTO is in an on (contact) state. As the mechanism of this PTO, for example, a mechanism that operates a mechanical lever to connect and disconnect power with a gear,
A mechanism (for example, see Japanese Patent Laid-Open No. 62-64630) in which power is connected and disconnected by an electromagnetic clutch is generally known. In any of the above mechanism, PT
When turning on the O, it is dangerous to disengage the traveling clutch and leave the change gear in the neutral state.

By the way, it is sufficient to rotate this type of hydraulic pump at about 1000 to 1200 rpm, and even if the number of rotations is increased more than that, energy is lost and wear of the device is only increased. Further, the loading speed of the refuse collecting vehicle is legally regulated in consideration of safety, for example, in the case of the rotating plate method, the time required for the empty cycle is not faster than 10 seconds. Nevertheless, when dust is loaded or discharged, an operator may step on the accelerator pedal to increase the output of the dust, which may accelerate the rotation of the engine and eventually the hydraulic pump.

In order to improve this, conventionally, for example, in Japanese Utility Model Laid-Open No. 62-157705.
As an issue, when the accelerator pedal is stepped on beyond a certain amount, this is detected by a sensor via the operating rod that connects the accelerator lever of the engine and the rotary solenoid, and the operation of the dust loading device is stopped. In Japanese Patent Laid-Open No. 60-14721, a plunger pump with variable discharge control is used as a hydraulic pump so that the discharge amount does not exceed a certain flow rate even if the rotation speed of the pump increases. A shunt valve is installed between the hydraulic pump and the loading hydraulic circuit to keep the amount of oil flowing in the loading hydraulic circuit constant even if the inlet flow rate of this shunt valve increases as the pump speed increases. Various proposals have been made in which the retained oil is bypassed to the oil tank.

[Problems to be solved by the device]

However, when the lever type is used as the PTO, the one described in the above Japanese Utility Model Publication No. 62-157705 is
Even if the lever is automatically operated to disengage the gears from each other, the lever may not be easily disengaged and the gear may not be turned off. Therefore, the usable range is extremely limited. In addition, the one that uses a plunger pump and a shunt valve to prevent the loading speed from increasing even if the engine speed is increased to make the pump rotate faster (hereinafter referred to as the constant speed control method) Since the device itself is operating, a worker may unnecessarily increase the speed of the engine, which causes various problems such as noise and increase in hydraulic pressure.

In view of the above, the present invention stops the operation of the loading device itself without adopting a constant speed control system when the engine is accelerated by a predetermined amount or more, and is structurally relatively simple and excellent in versatility. The purpose is to provide things.

[Means for solving problems]

In order to achieve the above object, the control device for a dust collecting vehicle according to the present invention is configured such that a hydraulic pump for supplying pressure oil to a loading hydraulic circuit of a loading device is driven by a running engine, and a loading hydraulic pressure is set. In a loading control device for a dust collecting vehicle equipped with an electric circuit for circuit control, it operates at the outlet side of the hydraulic pump when the discharge amount of the pump reaches a predetermined flow rate, and the spool protrudes to the outside during operation. In addition to interposing the relief valve described above, a detector that operates by the protrusion of the spool is arranged on the side of the spool, and the electric circuit for controlling the loading hydraulic circuit is turned on / off by the signal of this detector. It is designed to be controlled.

[Action]

According to the present invention configured as described above, when the operator depresses the accelerator more than necessary to increase the speed of the engine and the rotational speed of the hydraulic pump increases, the outlet side of the hydraulic pump increases as the speed increases. The flow rate (discharge amount) increases. And
When this flow rate exceeds a certain amount, the relief valve is operated to bypass the oil to the hydraulic tank, and at the same time the detector is operated with the protruding spool at the time of this operation. It is possible to disconnect the circuit and reliably stop the loading device.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows an external view of the refuse collection vehicle. A tailgate 2 is arranged at the rear of the refuse storage box 1 so as to close this opening, and the tailgate 2 rotates to the dust storage box 1 at its upper end. The tailgate 2 is rotatably supported and has a rotating panel 4 that rotates with the rotation of the motor 3 and a pushing panel 6 that swings with the operation of the pushing cylinder 5 inside the tailgate 2. The device 7 is built in. Further, a discharge cylinder 9 for dumping the dust container 1 to the rear is provided between the chassis 8 and the dust container 1.

On the other hand, a hydraulic pump 10 which supplies pressure oil to the actuators 3, 5 and 7 and operates them is connected to a traveling engine 12 via a PTO (power take-off device) 11 and
The hydraulic pump 10 is connected to the traveling engine 12 when O11 is turned on (contact), and is rotated by the rotation of the engine 12.

As shown in FIGS. 1 and 2, the outlet side of the hydraulic pump 10 is connected to an oil supply port P of a 3-port hydraulic valve 13 having the same structure as a general flow control panel or unload valve, and The load port A of the hydraulic valve 13 is connected to a loading hydraulic circuit that supplies oil to the actuators 3, 5 and 7, etc., and the return port T is connected to a bypass circuit to the oil tank 14.

Inside the hydraulic valve 13, an orifice 15 for restricting the amount of oil flowing from the oil supply port P to the load port A and a relief valve 16 for branching the downstream side of the orifice 15 and guiding the oil to the return port T during operation are built in. This orifice 15
The relief valve 16 is configured to switch depending on the pressure difference between before and after.

That is, in the hydraulic valve 13, oil is normally supplied from the oil supply port P side through the load port A to the loading hydraulic circuit, but the flow rate on the oil supply port P side increases above the set flow rate, and before the orifice 15. When the pilot pressure P _{1 of} is larger than the pilot pressure P ₂ after the orifice 15 and is larger than the spring force of the relief valve 16, the relief valve 16 is switched by this pressure P ₁ and the oil from the oil supply port P side is removed. Oil tank 14 from return port T through relief valve 16
It has been flowing to.

Inside this relief valve 16 is a spool that projects outside when it is switched by pressure P ₁ as described above.
17 is provided, and a detector 18 which is operated by the protrusion of the spool 17 is arranged on the side of the spool 17.

As a result, when the flow rate of the hydraulic pipe 13 on the discharge port P side increases and the relief valve 16 is switched, the spool 17 inside this protrudes by the stroke S to activate the detector 18, which causes the relief valve 16 to switch. It is like detecting that it has crossed.

FIG. 3 shows an electric circuit for controlling the loading hydraulic circuit. A relay CR and a loading hydraulic circuit are provided in parallel between a pair of positive and negative power supply buses 19 and 20. This relay CR
Includes a normally-closed stop switch 21, a normally-closed contact in parallel with a loading switch 22, which is opened when the detector 18 is activated by the protrusion of the spool 17 as described above. An exciting circuit composed of Cr ₁ is connected in series, and a normally open contact Cr _{2 that} is closed by exciting the relay CR is connected in series to the loading circuit.

As a result, the relay CR is excited when the loading pump 22 is closed by pushing it by hand, and this excitation closes the normally open contacts Cr ₁ and Cr ₂ which are the contact parts, and the relay C is released even when the loading button 22 is released.
A current is applied to D and a self-holding circuit is established by the normally open contact Cr ₁ and the normally closed contact Cr ₂ is also kept closed, which causes current to flow in the loading hydraulic circuit to perform loading work.

When stopping the loading work, press the stop switch 21 to stop the current from flowing through the relay CR, release the self-holding by the normally open contact Cr _{1 and} open the normally open contact Cr ₂ , and thereby The operation of the loading device is stopped by stopping the supply of current to the loading hydraulic circuit.

Then, even when the detector 18 detects switching of the relief valve 16 as described above, the detection switch 18 'which is closed by the signal of the detector 18 stops the current from flowing to the relay CR and the normally open contact Cr. _The self-holding by ₁ is released and the normally open contact Cr ₂ is opened, whereby the supply of current to the loading hydraulic circuit is stopped, and the operation of the loading device is stopped.

As a result, the engine 12 is accelerated, and when the discharge amount of the hydraulic pump 10 increases more than the set value due to this acceleration, the loading device is automatically stopped, and therefore the engine 12 is accelerated any further. Since it becomes impossible to do so, the worker does not uselessly accelerate the engine 12.

When the loading operation is restarted, this is done by stopping the depression of the accelerator pedal and pressing the loading button 22 again. Normally, the driver is in the driver's seat and the operator is in the vicinity of the tailgate 2. However, it is safe because the loading operation cannot be restarted only by the intention of the driving vehicle.

That is, for example, if the unloading valve is used to stop the loading device, when the accelerator pedal is stopped, the inlet flow rate of this valve returns to the set value, and at the same time, the loading device also reactivates. Although this poses a danger to workers on the side, this danger can be prevented.

[Effect of device]

Since the present invention is configured as described above, even if the driver depresses the accelerator pedal and tries to carry out the loading work at a faster cycle than the standard, the engine is accelerated and the discharge amount of the hydraulic pump exceeds the set value. As the load increases, the loading device will stop automatically, preventing the loading work from speeding up due to the acceleration of the engine and performing the loading work safely, as well as the noise and hydraulic pressure due to the acceleration of the engine. It is possible to increase and save wasteful fuel consumption.

In addition, the structure is relatively simple, and since it can be applied to vehicles of all types by only installing a detector through a relief valve, it is excellent in versatility.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a plan view of a hydraulic valve, Fig. 2 is a hydraulic circuit diagram from a hydraulic pump to a hydraulic valve, Fig. 3 is an electric circuit diagram, and Fig. 4 is a dust collecting system. It is an external view of a car. 1 ... Dust storage box, 2 ... Tailgate, 3 ... Motor, 4 ... Rotating panel, 5 ... Pushing cylinder, 6 ... Pushing panel, 7 ... Loading device, 10 ... Hydraulic pump, 11 ......
PTO (power take-off device), 12 ... engine, 13 ... hydraulic valve, 15 ... orifice, 16 ... relief valve, 17 ...
… Spool, 18 …… Detector, 18 ′ …… Detection switch,
21 …… Stop switch, 22 …… Load button.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A loading machine for a garbage truck, comprising a hydraulic pump for supplying pressure oil to a loading hydraulic circuit of a loading device driven by a running engine, and an electric circuit for controlling the loading hydraulic circuit. In the intake control device, a relief valve is provided on the outlet side of the hydraulic pump, the relief valve being activated when the discharge amount of the pump reaches a predetermined flow rate so that the spool protrudes to the outside during the operation. A detector operated by the protrusion of the spool is disposed on one side, and the electric circuit for controlling the loading hydraulic circuit is turned on / off by a signal from the detector. Loading device.