JPH0380685B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention mainly relates to a drive control device for a garbage pushing device installed in a vehicle.

<Prior Art> Conventionally, a garbage pushing device connects a hydraulic cylinder to a compression pushing plate for pushing garbage, and connects this hydraulic cylinder to a hydraulic pump driven by an engine via an electromagnetic switching valve. Widely used are electromagnetic switching valves in which a solenoid is energized to perform a series of cycle operations.

Previously, the present inventors proposed a drive control device in Japanese Patent Publication No. 59-30601 that efficiently pushes this type of garbage pushing device in accordance with the rotational speed of a hydraulic pump. In this drive control device, as shown in FIG. 3, a drive shaft 22 connected to a power extraction device 21 of the engine rotates a hydraulic pump 23, and a proximity sensing device 24 connects a proximity plate 22 fixed to the drive shaft 22. The rotation of the motor is sensed and an electrical signal corresponding to the rotation speed is output to the switching control device 26. As shown in FIG. 4, the switching control device 26 includes a counting circuit L that counts an electrical signal representing the number of revolutions of the hydraulic pump 23 inputted from the proximity sensing device 24, and a counting circuit L that counts electrical signals representing the rotation speed of the hydraulic pump 23 inputted from the proximity sensing device 24, and Output circuit that outputs a signal when the rotation speed is reached
N ₁ , N ₂ , N ₃ , N ₄ , and output holding circuits M ₁ , M ₂ , which excite and demagnetize the respective solenoids S ₁ , S ₂ , S ₃ , and S ₄ in response to these output signals. Consists of M ₃ and M ₄ . As shown in the figure, the output circuit group N and the output holding circuit group M are excitation signal lines a, b, c, d and demagnetization signal lines e, f, g, h, and the output circuit _N4 and the counting circuit L are connected to a zero clear line i. and the entire switching control device 26 is connected to a DC power source. If the set rotational values of the output circuits N ₁ , N ₂ , N ₃ , and N ₄ are each 175146200, for example, then the output holding circuit group as the count value of the counting circuit L (actual rotational speed of the hydraulic pump) n _L increases. The operation of M is as follows. When n _L becomes 1, solenoid S ₁ is excited from output circuit N ₁ via excitation signal line a and output holding circuit M ₁ , and n _L
When becomes 75, the output circuit _N2 is connected to the degaussing signal line e and the output holding circuit _M1 , and the excitation signal line b and the output holding circuit
M ₂ , through the excitation signal line c and the output holding circuit M ₃ , the solenoid S ₁ is deenergized, the solenoid S ₂ is energized,
When the solenoid S ₃ is energized and n _L becomes 146, the demagnetizing signal line g and the output holding circuit M 3 are connected from the output circuit N ₃ to the output holding circuit M ₃ .
Solenoid _S3 is deenergized and solenoid _S4 is energized through the excitation signal line d and output holding circuit _M4 , and n _L
When becomes 200, the solenoid S ₄ is demagnetized from the output circuit N ₄ via the demagnetization signal line h and the output holding circuit M ₄ , and the coefficient circuit L is cleared to zero via the zero clear line i (n _L = 0). and completes one cycle of operation.

FIG. 5 shows such solenoids S ₁ , S ₂ , S ₃ ,
Hydraulic system switched by electromagnetic switching valve with S ₄ ,
1 shows a garbage pushing device driven and controlled by the device. The discharge pipe 27 of the hydraulic pump 23 is connected to an electromagnetic switching valve 28 having solenoids S ₃ and S ₄ , and further connected via a connecting pipe 29 to another electromagnetic switching valve 28 ′ having solenoids S ₁ and S ₂ . This electromagnetic switching valve 28' is connected to an oil reservoir 31 through a return pipe 30.
A relief valve 32 is provided in the middle of the discharge pipe 27, which opens when the hydraulic pressure in the pipe exceeds a predetermined pressure and returns the hydraulic oil to the oil reservoir 31. The electromagnetic switching valve 28 is connected to the piston side chamber 36 and the rod side chamber 37 of the first hydraulic cylinder 35 via conduits 33 and 34, respectively, and the electromagnetic switching valve 28' is connected to the second hydraulic cylinder 35 via conduits 38 and 39. ’ piston side chamber 3
6' and rod side chamber 37', respectively. The tip of the piston rod 40 of the first hydraulic cylinder 35 is connected to the base 41a of the compression pushing plate 41 with a pin, and the piston rod 40' of the second hydraulic cylinder 35' is connected to the compression pushing plate 41 through a link 42.
Further, the tip of a link 43 whose one end is pivoted 44 to a garbage disposal box (not shown) is connected to the connection between the piston rod 40' and the link 42.

The operating process of the dust pushing device having the above configuration will be described as follows based on the solenoid excitation cycle described above with reference to FIG.

(a) Return stroke 1≦n _L <75 Only solenoid S ₁ is energized, and the hydraulic oil is discharged from the hydraulic pump 23 to the discharge pipe 27, as shown by the arrow in the figure.
The piston rod 40' is supplied to the piston side chamber 36' of the second hydraulic cylinder 35' through the connecting pipe 29, the electromagnetic switching valve 28', and the conduit 38, and the piston rod 40' protrudes to the most extended position. It is rotated upward around the base 41a, and is ready for the input of garbage.

(b) Compression stroke 75≦n _L <146 Solenoids S ₃ and S ₂ are excited, and the hydraulic oil flows into the piston side chamber 36 of the first hydraulic cylinder 35 as shown by the arrow.
Next, the rod side chamber 3 of the second hydraulic cylinder 35'
7', the piston rod 40 protrudes to the most extended position, while the piston rod 40' retracts to the most retracted position, and the compression pushing plate 41 remains in a substantially horizontal state via the piston rod 40 and links 42 and 43. It descends and compresses the garbage thrown in.

(c) Pushing stroke 146≦n _L <200 Only the solenoid _S4 is energized, hydraulic oil is supplied to the rod side chamber 37 of the first hydraulic cylinder 35 as shown by the arrow, and the piston rod 40 is retracted to the most retracted position and compressed. The plate 41 rotates to the left front via the piston rod 40 and links 42, 43, and pushes the compressed garbage into a garbage storage box (not shown).

When n _L = 200, the count value becomes zero clear line (n _L = 0)
One cycle of operation is completed, and the same cycle is repeated again.

The drive control device previously proposed by the present inventors is
As described above, the dust pushing device was operated efficiently according to the rotation speed of the hydraulic pump.

<Problems to be Solved by the Invention> However, the drive control device described above has a structure in which the operating cycle of the garbage pushing device becomes shorter as the hydraulic pump rotates at a higher speed, so when pushing the garbage, it is usually kept at a constant rotation speed. When an engine is rotated at high speed by pressing down on the accelerator pedal, there is a problem in that the high-speed operation of the push-in device repeatedly applies abnormal force to the hydraulic system and mechanical parts, causing damage to them. Also,
Workers often press the accelerator in an attempt to finish the pushing work quickly, and in such cases, there is a risk of personal injury such as the worker getting caught in the pushing device. Furthermore, when the garbage collection vehicle is rented, the rental company has a strong desire to protect the pushing device from harsh use by the renter. Therefore, it is absolutely necessary to operate the dust pushing device at a speed below a predetermined speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a drive control device that can stop the operation of a garbage pushing device when the engine and hydraulic pump rotate at a predetermined speed or higher.

<Means for Solving the Problems> In order to achieve the above object, the configuration of the drive control device of the present invention is such that the hydraulic cylinder that drives the compression plate that pushes the garbage into the garbage storage box is connected to the primary side and the secondary side. Connected to a hydraulic pump via an electromagnetic switching valve that has a neutral position that cuts off communication with the next side and multiple switching positions that communicate between the primary and secondary sides, and detects the rotation speed of this hydraulic pump. The number of revolutions of the hydraulic pump is counted in response to an output signal from the proximity sensing device, and when a predetermined number of revolutions is counted, the counted value is reset and the counting is repeated again, and the number of revolutions of the hydraulic pump is counted. and a preset predetermined rotation speed, and a switching control device that controls the switching of the electromagnetic switching valve using an output signal according to the comparison result, controls the hydraulic cylinder via the electromagnetic switching valve. In a dust pushing device that expands and contracts in a predetermined cycle, the number of rotations of the hydraulic pump per unit time and the set rotation number per unit time of the hydraulic pump are created based on a signal representing the number of rotations of the hydraulic pump output from the proximity sensing device. If the number of revolutions of the hydraulic pump per unit time is less than the set number of revolutions per unit time, the output signal from the proximity sensing device is sent to the switching control device, The present invention is characterized in that a signal control device is provided that positions the electromagnetic switching valve at a neutral position via the switching control device if the rotation speed of the hydraulic pump is equal to or higher than the set rotation speed per unit time.

<Function> If the number of revolutions of the hydraulic pump per unit time is less than the set number of revolutions per unit time, the signal control device will
A signal representing the rotational speed of the hydraulic pump outputted from the proximity sensing device is sent to the switching control device. The switching control device counts the above-mentioned signals, compares the counted value with a predetermined rotation speed, and switches the electromagnetic switching valve according to the comparison result to extend or contract the hydraulic cylinder. The compression pushing plate is cycle-driven, and the garbage pushing device repeats a predetermined cycle operation according to the rotation speed of the hydraulic pump. On the other hand, when the number of revolutions of the hydraulic pump per unit time is equal to or higher than the set number of revolutions per unit time, the signal control device positions the electromagnetic switching valve at the neutral position via the switching control device, and the garbage pushing device The operation also stops.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated examples.

Figure 1 shows a garbage collection vehicle, where 1 is a vehicle body frame, 2 is a garbage storage box mounted on the vehicle body frame 1, 3 is a garbage disposal box provided at the rear of the garbage storage box 2, and 4 is this garbage disposal box 3. 5 is an operation switch for switching between pushing and discharging garbage, 6 and 7 are push switches and stop switches provided on the outer surface of the garbage storage box 3, and 8 is an accelerator of the garbage collection vehicle. It's a pedal.

The garbage pushing device 4 has a compression pushing plate 41 and a base 41a of the compression pushing plate that is connected to a piston rod 40.
a first hydraulic cylinder 35 driven by a piston rod 40', and a second hydraulic cylinder 35' driven by a piston rod 40' via a link 42 and a link 43 whose one end is pivoted to the garbage disposal box 3; (see FIG. 2), and these structures are exactly the same as the garbage pushing device described in FIG.

When the operation switch 5 is switched to the discharge side, a discharge device (not shown) rotates the garbage disposal box 3 upward around the pivot point 9, and discharges the garbage in the garbage storage box 2 to the outside. . Further, the output of the engine, which is adjusted by the accelerator pedal 8, is transmitted to a hydraulic pump 23 via a drive shaft 22, as in FIG.
The proximity sensing device 24 senses the rotation of the proximity plate fixed to the drive shaft 22 and outputs an electric signal corresponding to the rotation speed to the switching control device 26.

FIG. 2 is a schematic diagram of a drive control device consisting of a hydraulic system for driving the garbage pushing device 4 and an electrical system for controlling it. The configuration of the hydraulic system is exactly the same as that described in FIG. 5, and the same reference numerals are given to the same structural members and the explanation thereof will be omitted. Further, in the electrical system shown on the right side of FIG. 2, 24 is the proximity sensing device described above, and 26 is the switching control device having the same configuration as in FIG. 4.

A signal control device 10 is provided between the proximity sensing device 24 and the switching control device 26. This signal control device 10 calculates a count per unit time of an electrical signal representing the number of rotations of the hydraulic pump, which is input from the proximity sensing device 24 via the counting circuit L (see FIG. 4) of the switching control device 26 and counted. The numerical value is compared with the set value input from the upper limit rotational speed setter 11, and if the counted value is less than the set value, the electrical signal continues to be sent to the switching control device 26, and if the counted value is greater than the set value, an alarm is activated. 12 and the base of the power transistor 13. Switching control device 2
6 is supplied with DC power from the terminal (+) through the aforementioned operation switch 5, push-in switch 6, normally closed stop switch 7, and the emitter and collector of the power transistor 13. It is possible to switch to the discharge device side 14. Stop switch 7 and power transistor 1
A well-known engine constant rotation device 15 is connected from the (+) side to the (-) side of the DC power source between the
controls the rotation of the engine at a constant speed so as to give the hydraulic pump a rotational speed optimal for pushing in dust even if the accelerator pedal 8 is not depressed. When the power transistor 13 receives an output signal from the signal control device 10, it cuts off the emitter and the collector to turn off the power to the switching control device 26. Further, the alarm device 12 receives an output signal from the signal control device 10 and uses a buzzer or lamp to notify that the hydraulic pump is rotating at a higher speed than a set value.

The operation of the drive control device for the dust pushing device having the above configuration will be described below.

First, when the operating switch 5 is switched to the garbage pushing device side and the pushing switch 6 is closed, the engine, which is rotated at a constant speed by the engine constant rotation device 15, rotates the hydraulic pump 23. The rotation speed of the hydraulic pump 23 is converted into an electrical signal by the proximity sensing device 24, and this electrical signal is inputted to the counting circuit L of the switching control device 26 via the signal control device 10 and counted. The upper limit rotation speed setting value of the hydraulic pump is preset in the upper limit rotation speed setting device 11 according to the type of garbage and the request of the operator. Then, the signal control device 10 compares the count value per unit time of the electric signal counted by the counting circuit L with the set value, and if the count value is less than the set value, switches the electric signal to the control device 26. Continue sending to. Then, the switching control device 26 operates in the same manner as described in FIG.
The same operation as described in the figure is carried out, and the dust pushing device 4 returns to compression depending on the rotation speed of the hydraulic pump.
A predetermined cycle operation consisting of pushing is repeated. On the other hand, when the operator depresses the accelerator pedal 8 to rotate the engine and hence the hydraulic pump 23 at high speed, and the above-mentioned count value exceeds the above-mentioned set value, the signal control device 10 sends a signal to the base of the alarm 12 and the power transistor 13. Output. Then, the power transistor 13 cuts off the emitter and collector to turn off the power to the switching control device 26, and the count value of the counting circuit L in the switching control device 26 becomes zero. As a result, solenoids S ₁ , S ₂ , S ₃ , and S ₄ are all demagnetized, and the electromagnetic switching valves 28 and 28' assume the neutral position.
The hydraulic oil is pump 23, discharge pipe 27, connecting pipe 29,
The return pipe 30 and the oil reservoir 31 are circulated without load, and the dust pushing device 4 stops operating. At the same time, the alarm 12
In response to an output signal from a signal control device 10, a buzzer or lamp notifies that the hydraulic pump is rotating at a higher speed than a set value. The switching control device 26 whose power has been turned off in this manner is re-energized by pressing a reset button (not shown) in the signal control device 10. Further, in an emergency, the normally closed stop switch 7 can be opened to stop the garbage pushing device 4. Further, when the operation switch 5 is switched to the discharge device side 14, the garbage disposal box 3 is rotated upward around the pivot point 9, and the garbage in the garbage storage box 2 is discharged to the outside.

In the embodiment described above, since the alarm 12 is provided, the operator can immediately know when the hydraulic pump rotates at a high speed exceeding a set value and the switching control device 26 is turned off.

In addition, in the above embodiment, the engine constant rotation device 1
Although the rotational speed control No. 5 is fixed at a constant speed, this control speed may be changed in conjunction with the setting value of the upper limit rotational speed setting device 11. Further, although the signal control device 10 receives the count value of the electric signal representing the rotation speed of the hydraulic pump from the switching control device 26, the signal control device itself may be provided with a counting circuit.

<Effects of the Invention> As is clear from the above explanation, the drive control device for the garbage pushing device of the present invention detects the proximity sensing device when the number of revolutions of the hydraulic pump per unit time is less than the set number of revolutions per unit time. A signal indicating the rotation speed of the hydraulic pump output from If the rotation speed exceeds the set value, the control device is equipped with a signal control device that positions the electromagnetic switching valve at the neutral position via the switching control device and stops the operation of the garbage pushing device, so that the compression pushing plate does not exceed the set value. Therefore, the hydraulic system and mechanical parts of the garbage pushing device will not be damaged due to stress, and personal accidents will not occur due to the high speed operation of the garbage pushing device.

[Brief explanation of drawings]

Fig. 1 is a side view of a garbage collection vehicle equipped with the drive control device of the present invention, Fig. 2 is a schematic diagram of the drive control device, and Fig. 3 is a rotation speed sensor of a hydraulic pump previously proposed by the present inventors. FIG. 4 is an electric circuit diagram of a control device connected to the rotation speed sensing section in FIG. 3;
FIG. 5 is an operational diagram of a drive control device previously proposed by the present inventors. 2... Garbage storage box, 4... Garbage pushing device, 10
... Signal control device, 11 ... Upper limit rotation speed setting device, 12 ... Alarm device, 13 ... Power transistor, 23 ... Hydraulic pump, 24 ... Proximity sensing device, 26 ... Switching control device, 28, 28 '... Solenoid switching valve, 35, 35'... Hydraulic cylinder, S ₁ ,
S ₂ , S ₃ , S ₄ ... Solenoid.

Claims (1)

[Scope of Claims] 1. A hydraulic cylinder that drives a compression pushing plate that pushes garbage into a garbage storage box is placed in a neutral position that cuts off between the primary side and the secondary side, and between the primary side and the secondary side. is connected to the hydraulic pump via an electromagnetic switching valve having a plurality of switching positions communicating with each other, and counts the number of rotations of the hydraulic pump in response to an output signal from a proximity sensing device that detects the number of rotations of the hydraulic pump. At the same time, when a predetermined number of revolutions is counted, the counted value is reset and the count is repeated again, and the number of revolutions of the hydraulic pump is compared with a predetermined number of revolutions set in advance, and the number of revolutions is determined according to the comparison result. In the garbage pushing device, the hydraulic cylinder is telescopically operated in a predetermined cycle via the electromagnetic switching valve by a switching control device that switches and controls the electromagnetic switching valve in response to an output signal, the output signal being output from the proximity sensing device. The number of revolutions of the hydraulic pump per unit time created based on the signal representing the number of revolutions of the hydraulic pump is compared with the set number of revolutions per unit time, and the number of revolutions of the hydraulic pump per unit time is determined by the number of revolutions per unit time. If the number of revolutions per unit time is less than the set number of revolutions per unit time, the output signal from the proximity sensing device is sent to the switching control device, and if the number of revolutions of the hydraulic pump per unit time is greater than or equal to the set number of revolutions per unit time, the switching control is performed. A drive control device for a garbage pushing device, characterized in that a signal control device is provided for positioning the electromagnetic switching valve in a neutral position via the device.