JPH0344726Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a hydraulic system for a garbage collection vehicle, and in particular to a discharge cylinder device for garbage storage box dumping, a dump cylinder device for tailgate dumping, and a push panel drive. The present invention relates to a hydraulic system for a garbage collection vehicle in which a pressure oil source is connected to a push-in cylinder device and a rotary motor device for driving a rotating panel via a supply pipe, and includes two hydraulic pump devices.

[Prior Art] Generally, a rotating panel driven by a rotating motor device and a push-in panel driven by a push-in cylinder device are built into a tailgate pivotally attached to the rear opening end of a garbage storage box, and both A garbage collection vehicle is known in which panels work together to load garbage into a garbage storage box.

In addition to the rotary motor device and push cylinder device, this type of conventional garbage collection vehicle also includes a dump cylinder device for dumping the tailgate to the rear of the garbage storage box when discharging garbage, and a rear end of the garbage storage box. and an ejection cylinder device for flipping the front portion upward with the front portion as the base end, and each of these hydraulic drive devices drives a single hydraulic motor device driven by the engine of the garbage truck. It is now being driven as an oil source.

FIG. 3 shows a hydraulic circuit diagram of a conventional garbage collection vehicle of this type, and the discharge cylinder device 50, dump cylinder device 51, push cylinder device 52, and rotary motor device 63 each have a 3-port, 4-position electromagnetic switching valve. 55, 56, 57 and 58 are connected.

In addition, these electromagnetic switching valves 55, 56, 57,
A supply pipe line 61 for supplying pressure oil from the hydraulic pump device 60 and a return pipe line 63 for recovering drain to the hydraulic tank 62 are connected to 58.
An unload valve 65 as a safety device for this hydraulic circuit is connected between the supply pipe 61 and the return pipe 63 via a branch pipe 66. In addition, code 6
8 is a check valve connected in the middle of the supply pipe 61.

By the way, in the hydraulic circuit of this type of conventional garbage collection vehicle, the hydraulic pump device 60 serving as the pressure oil source is a single constant-capacity pump, whereas the load applied to the garbage loading device is applied to the garbage storage box 1. The size increases as more garbage is loaded inside. Therefore, if the pressure oil pump device 60 is set to match the pressure and flow rate of the pressure oil supplied during high loads, an unnecessary flow rate will be supplied during low loads.
There was a problem that the driving force of the hydraulic pump device 60 increased and became uneconomical.

Therefore, conventionally, a hydraulic circuit has been proposed in which the hydraulic pump device 60 is a variable displacement pump and the flow rate is reduced only when the pressure is high (Japanese Patent Laid-Open No. 1983-1989-1).
Publication No. 188201).

[Problem that the invention attempts to solve]

However, as mentioned above, the hydraulic pump device 6
0 is a variable displacement pump that reduces the flow rate when the pressure is high, there is a problem that the flow rate in the supply pipe is large when the pressure is constant, and the pressure loss in the supply pipe increases, making it uneconomical. Ta.

Further, the above-mentioned hydraulic circuit has problems in that the response time when switching the flow rate is long and the structure is complicated.

Therefore, the purpose of the present invention is to solve the problems of the above-mentioned conventional technology, and to create an economical and simple system that can drive a hydraulic pump device with an appropriate driving force according to the load applied to the garbage loading device. An object of the present invention is to provide a hydraulic system for a garbage collection vehicle consisting of the following configurations.

[Means for solving problems]

In order to achieve the above object, the present invention provides hydraulic pressure for a garbage collection vehicle in which a supply pipe line from a pressure oil source is connected to a hydraulic drive device for loading garbage and a hydraulic drive device for discharging garbage via a switching valve. In the circuit, the pressure oil source is configured with first and second hydraulic pump devices,
The first hydraulic pump device is sequentially connected to each hydraulic drive device, the second hydraulic pump device is connected to a garbage loading hydraulic drive device, and the second hydraulic pump device is connected to the hydraulic drive device for loading garbage.
The present invention is characterized in that an unload valve is incorporated in the supply line of the second hydraulic pump device to directly return the pressure oil of the second hydraulic pump device to the oil tank when the hydraulic pressure exceeds a predetermined value.

〔Example〕

An embodiment of the hydraulic circuit for a garbage collection vehicle according to the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 1 indicates a garbage storage box. A bracket 2 is fixed to the rear upper end of the garbage storage box 1, and a tailgate 4 is pivotally connected to this bracket 2 via a pivot 3. This tailgate 4
is equipped with a pair of side plates 5, 5 and a sump 6 for temporarily storing garbage, and a garbage inlet 7 on the back side.
is opened. On the other hand, a rotating shaft 8 is mounted between the side plates 5, 5 in the lower region of the tailgate 4, and a panel-shaped rotating panel 10 that is rotated by a rotating motor device 9 is integrated with this rotating shaft 8. is firmly fixed. Further, a rotatable pivot shaft 1 is located above the rotation shaft 8 and is located between the side plates 5 and 5.
1 is mounted, and a panel-shaped push-in panel 12 is fixed to the pivot shaft 11. This push-in panel 12
The tip of the piston rod 13a of the push-in cylinder device 13 is pin-coupled via a pin 14 to the end of the cylinder 13b of the push-in cylinder device 13.
The rear end portion of the bracket 2 is pin-coupled to the bracket 2 via a pivot pin 15.

Further, the rear end of a cylinder 17a of a dump cylinder device 17 for dumping the tailgate 4 rearward during garbage discharge is hinged to the bracket 2 via the pivot shaft 3, and a piston rod 17b of the dump cylinder device 17 is connected to the bracket 2 via the pivot shaft 3. The operating end is a bracket 18 fixed to the side plate 5 of the tailgate 4.
is fixed to. A panel-shaped deflector 23 is fixed between the side plates 5, 5 to prevent dust from flowing backward.

On the other hand, a support bracket 19 is protruded from the rear lower end of the garbage storage box 1, and the support bracket 19 and the frame 20 of the garbage collection vehicle are hingedly connected by a pivot shaft 21. Further, the rear end of the cylinder 22b of the discharge cylinder device 22G is connected to the frame 20 with a pin, and the tip of the piston rod 22a is connected to the bottom of the garbage storage box 1 with a pin.

To load garbage with the garbage collection vehicle configured in this way, after inputting the garbage into the sump 6 from the garbage inlet 7, press an automatic loading push button (not shown) to enter the automatic loading operation cycle mode. Therefore, it is performed sequentially as follows.

The rotating panel 10 starts rotating clockwise and scoops up the garbage on the top surface of the sump 6, and then removes the garbage from the garbage storage box 1.
It stops at a position parallel to the floor surface (solid line position in Figure 1). The push-in panel 12 is swung backward around the pivot shaft 11 while the rotating panel 10 is rotating, and stops and waits at the backward limit position, and starts moving forward when the rotating panel 11 reaches the above-mentioned stop position. Push the garbage into the garbage storage box 1 and move it to the forward limit position (first
Stops at the solid line position in the figure).

On the other hand, in order to discharge dust, a switch is made to the electric control circuit for dust discharge. Then, the piston rod 17b of the dump cylinder device 17 is extended, and the tailgate 4 is rotated counterclockwise around the pivot shaft 3 and stopped at the extension limit position of the piston rod 17b. Thereafter, the piston rod 22a of the discharge cylinder device 22 is extended, and the garbage storage box 1 is rotated clockwise around the pivot shaft 21 and stopped at the extension limit position of the piston rod 22a. Thus, while the garbage storage box 1 is being rotated, the garbage gradually spills out to the rear of the garbage collection vehicle, and is completely discharged when it reaches a predetermined dumping position.

FIG. 2 shows a hydraulic circuit diagram of the garbage collection vehicle according to the present invention, in which the discharge cylinder device 22, the dump cylinder device 17, the push cylinder device 13, and the rotary motor device 9 each have a 3-port, 4-position electromagnetic switching valve 25, 26, 27, and 28 are connected.

On the other hand, numerals 31 and 32 indicate a first hydraulic pump device and a second hydraulic pump device, respectively, and both pump devices 31 and 32 are the engine 3 of the garbage collection vehicle.
4 (FIG. 1) and is coaxially connected to the engine 34.

The first hydraulic pump device 31 is a high-pressure, small-capacity hydraulic pump, and its supply line 36 is connected to the electromagnetic switching valves 25 and 2 via a first check valve 37.
6, 27, and 28 in sequence, and between the first hydraulic pump device 31 and the first check valve 37 is a first valve whose pressure is set slightly higher than the set value of the first hydraulic pump device 31. A load valve 38 is connected.

The second hydraulic pump device 32 is a medium-pressure, large-capacity hydraulic pump, and its supply line 40 is connected to the middle of the electromagnetic switching valve 26 and the electromagnetic switching valve 27 via a second check valve 41. The medium-pressure, large-capacity pressure oil from the second hydraulic pump device 32 is supplied only to the push cylinder device 13 and the rotary motor device 9, and is returned to the hydraulic tank 42 and recovered via the pipe line 43. There is. Further, a second unload valve 45 which is set to a predetermined pressure lower than the setting value of the first hydraulic pump device 31 is provided midway between the second hydraulic pump device 32 and the second check valve 41. The pilot line 46 of the second unload valve 45 is connected to the supply line 36 of the first hydraulic pump device 31.

By the way, in general, the driving force of a hydraulic pump device is expressed as L=P×Q/612...(1), where L: driving force KW P: pressure Kg/cm ² Q: flow rate /min, and The pressure loss in the supply pipes 36 and 40 is ΔP=k1ρlv ² /2g+k2ρv ² /2g (2) where, ΔP: pressure loss Kg/m ² v: flow rate of hydraulic oil m/sec g: gravity Acceleration m/sec ² l: Length of the pipe m k ₁ : Loss coefficient per 1 m k ₂ : Expressed as the sum of the loss coefficients of the parts in the pipe that generate resistance.

According to the present invention, as described above, the loading of garbage is performed sequentially according to the mode of the automatic loading operation cycle, and the rotating panel 10 scoops up the garbage on the upper surface of the sump 6 and the pushing panel 12 is pushed. At the stage of starting operation, pressure oil from the first hydraulic pump device 31 is supplied to the push cylinder device 13 or the rotary motor device 9 via the supply pipe line 36 and the electromagnetic switching valves 25 and 26.
The pressure oil from the second hydraulic pump device 32 is directly pushed into the cylinder device 13 through the supply lines 40 and 39.
Alternatively, it is supplied to the rotary motor device 9. At this time, since the length l of the supply pipes 40 and 39 of the second medium-pressure and large-capacity hydraulic pump device 32 is configured to be short, the pressure loss ΔP
can be reduced.

On the other hand, if garbage is continuously loaded into the garbage storage box 1, a large load will be applied when the pushing panel 12 pushes the garbage. In this case, when the pressure in the supply line 36 of the first hydraulic pump device 31 becomes high, the second unload valve 45 is activated via the pilot line 46, and the pressure oil from the second hydraulic pump device 31 is released. is collected in the hydraulic tank 42, and the push cylinder device 13 is driven only by the pressure oil from the high-pressure, small-capacity first hydraulic pump device 31. Therefore, the hydraulic oil in the supply pipes 36 and 39 in this case has a pressure P
is high, but the flow rate Q is small, and as is clear from equation (1) above, the driving force kw of the pump device can be reduced, and the flow velocity v is also reduced, so as is clear from equation (2) above, the pressure Loss ΔP can be reduced.

In addition, when discharging dust, the discharge cylinder device 22
Alternatively, since only the dump cylinder device 17 is used, the pressure oil from the second hydraulic motor device 32 is directly supplied to the hydraulic tank 42 via the supply pipes 40, 39, the electromagnetic switching valves 27, 28, and the return pipe 43. Return The second hydraulic motor device 32 is operated under no load, and each cylinder device 17, 22 is driven by the pressure oil from the high pressure, small capacity first hydraulic motor device 31. Therefore, as in the case described above, the driving force kw and pressure loss ΔP of the pump device can be reduced.

Although an embodiment of the garbage collection vehicle has been described in which separate hydraulic drive devices are provided for the tailgate dump and the push-in panel drive, according to the present invention, these hydraulic drive devices can be used as a single unit. It is clear that the present invention can be applied to known garbage collection vehicles.

[Effect of idea]

As is clear from the above description, according to the present invention, the pressure oil source is composed of first and second hydraulic pump devices, the first hydraulic pump device is connected to each of the hydraulic drive devices, and The second hydraulic pump device is connected to the hydraulic drive devices for driving the push-in panel and the rotating panel, and when a high load is applied, the first hydraulic pump device drives the hydraulic drive device. , the length of the supply pipe of the second hydraulic pump device can be shortened, pressure loss within the pipe can be reduced, and an appropriate driving force can be applied according to the load applied to the garbage loading device. Since the hydraulic pump device is driven, the power from the engine can be used effectively.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a garbage collection vehicle according to the present invention, FIG. 2 is a hydraulic circuit diagram of the garbage collection vehicle according to the present invention, and FIG. 3 is a hydraulic circuit diagram of a conventional garbage collection vehicle. 1... Garbage storage box, 4... Tailgate, 9...
...Rotating motor device, 10... Rotating panel, 12...
...Pushing panel, 13...Pushing cylinder device, 17
... dump cylinder device, 22 ... discharge cylinder device, 31 ... first hydraulic motor device, 32 ...
Second hydraulic motor device, 38...first unload valve, 45...second unload valve.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a hydraulic circuit for a garbage collection vehicle in which a supply pipe line from a pressure oil source is connected to a hydraulic drive device for loading garbage and a hydraulic drive device for discharging garbage via a switching valve, The pressure oil source is configured with first and second hydraulic pump devices, and the first hydraulic pump device is connected to both hydraulic drive devices in sequence,
The second hydraulic pump device is connected to the garbage loading hydraulic drive device, and when a predetermined hydraulic pressure is exceeded in the middle of the supply pipe line of the second hydraulic pump device, the second hydraulic pump device is activated. A hydraulic system for a garbage collection vehicle characterized by incorporating an unload valve that returns pressure oil directly to an oil tank. 2. Utility model registration claim 1, characterized in that the first hydraulic pump device is of high pressure and small capacity, and the second hydraulic pump device is of medium pressure and large capacity.
Hydraulic system for garbage collection vehicles as described in section.