JPH01150603A - Drive control device for dust push-in device - Google Patents

Abstract

PURPOSE:To keep a dust push-in device from increasing in speed more than designated by controlling a by-pass solenoid directional control valve in such a manner as to close when the rotational frequency of a hydraulic pump per unit hour is less than a preset rotational frequency and open when it is more than the preset rotational frequency in the dust push-in device loaded on a car. CONSTITUTION:The rotational frequency of a hydraulic pump is converted to an electric signal by a proximity sensor 24 and input to a changeover control device 26 through a signal control device 10. Thus, the changeover control device 26 forces a dust push-in device 4 to cycle-operate according to the rotational frequency of the hydraulic pump. At this time, the upper limit rotating speed set value is taken in the signal control device 10 from an upper limit rotating speed setting device 11 to be compared with the rotational frequency of the hydraulic pump per unit hour. When the rotational frequency is under the preset value, a changeover switch 53 is put in the open state to close a by-pass solenoid valve 51. On the contrary, when it is the preset value or more, the changeover switch 53 is closed to open the by-pass solenoid valve 51. Thus, the rotational frequency can be kept less than the preset value.

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.

Once upon a time, the present inventors proposed in Japanese Patent Publication No. 59-30601 a drive control device for efficiently pushing 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.
The proximity sensing device 24 rotates and drives the! +b
The rotation of the proximity plate 25 fixed to the switch 22 is sensed, and an electric 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 that counts electrical signals from the proximity sensing device 24 and does not represent the number of revolutions of the hydraulic pump 23 manually operated, and this counting value is set in advance. An output circuit N7 outputs a signal when each rotational speed is reached. Nt, N3. N4, and each solenoid S in response to these output signals.
Output holding circuit M, which excites and demagnetizes S, , S, , N4.
M,,M,.

It consists of M4. As shown in the figure, the output circuit group N and the output holding circuit group M are connected to excitation signal lines a, b, c, d and demagnetization signal lines e, r, g, h, and the output circuit N4 and the counting circuit are connected to a zero clear line i. The entire switching control device 26 is connected to a DC power source. The above output circuit N1. N2
．． For example, set the rotation values of N, , and N4 to 1.75, 1.75, and 1.75, respectively.
If it is 146,200, the count value of the counting circuit (AI +
The operation of the output holding circuit group M as the measured rotational speed of the pressure pump (nL) increases is as follows. When nL becomes 1, the solenoid S is excited from the output horn circuit N1 via the excitation signal line a and the output horn holding circuit M, and when n becomes 75,
From the output circuit N, to the degaussing signal line e and the output horn holding circuit M3,
The solenoid S1 is deenergized, the solenoid S is energized, the solenoid S3 is energized, and n(,
When becomes 146, the solenoid S is demagnetized from the output circuit N via the demagnetizing signal line g and the output holding circuit M3, and the excitation signal line d and the output holding circuit M4, and the solenoid S4 is excited, and when nL becomes 200, , the solenoid S4 is demagnetized from the output circuit N4 via the demagnetizing signal line and the output holding circuit M4, and the counter circuit is cleared to zero (n, = 0) via the zero clear line i, resulting in one cycle of operation. finish.

Figure 5 shows such solenoids S, , S, , N3°N
4 shows a hydraulic system that is switched by an electromagnetic switching valve, and a garbage pushing device that is driven and controlled by the hydraulic system. The discharge pipe 27 of the hydraulic pump 23 is connected to the solenoid S3. S, is connected to an electromagnetic switching valve 28 with a solenoid S, and is further connected to another electromagnetic switching valve 28' with a solenoid S, S, via a connecting pipe 29, and this electromagnetic switching valve 28' is connected to an oil It is connected to the reservoir 31. In the middle of the discharge pipe 27, when the hydraulic pressure J in the pipe reaches a predetermined level or more, it opens and drains the hydraulic oil into an oil reservoir 3.
A relief valve 32 is provided to return the temperature to 1. Solenoid switching valve 28
are connected to the piston side chamber 36 and rod side chamber 37 of the first hydraulic cylinder 35 via conduits 33 and 34, respectively,
The electromagnetic switching valve 28' connects the piston side chamber 36' and the rod side chamber 37 of the second hydraulic cylinder 35' through conduits 38 and 39.
“They are connected to each other.

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. The distal end portion 41b is connected to the distal end portion 41b, and the distal end of a link 43 whose one end is pivoted 44 to a garbage disposal box (not shown) is connected to the connecting portion between the piston rod 40° and the link 42.

The operation process of the above-mentioned sliding dust pushing device will be described as follows based on the above-mentioned solenoid excitation cycle with reference to FIG.

(a) Return stroke 1≦nt, <75 solenoid S,
Only the hydraulic pump 23 is energized, and the hydraulic oil flows from the hydraulic pump 23 to the discharge pipe 27 and the connecting pipe 29. Solenoid switching valve 28
°, is supplied via the conduit 38 to the piston side chamber 36° of the second hydraulic cylinder 35', the piston rod 40' projects to its most extended position, and the compression push plate 41 is moved upwardly around the base 41a via links 42, 43. It is rotated to prepare for the input of garbage.

(b) Compression stroke 75≦nt, < 146 solenoid S, 84 is energized, and hydraulic oil is supplied to the piston side chamber 36 of the first hydraulic cylinder 35 and then to the rod side chamber 37' of the second hydraulic cylinder 35' as shown by the arrow. Then, the piston rod 40 protrudes to the most extended position, while the piston rod 40° retracts to the most contracted position, and the compression pushing plate 4I descends while maintaining a substantially horizontal state via the piston rod 40 and links 42 and 43. and compress the thrown-in garbage.

(c) Pushing stroke 146≦”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, the piston rod 40 is retracted to the most retracted position, and the compression push is performed. The plate 41 is rotated forward to the left via the piston rod 40 and links 42 and 43, and the compressed garbage is placed in a garbage storage box (not shown).
Push it into.

nL: When it reaches 200, the count value becomes zero (nt).

-〇), one cycle of operation is completed, and the same cycle is repeated again.

As described above, the drive control device proposed by the present inventors efficiently operates the garbage pushing device 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 the rotation speed is usually maintained at a constant speed when pushing the garbage. When the engine is rotated at high speed by pressing the accelerator pedal,
There is a problem in that the high-speed operation of the pushing device repeatedly applies abnormal force to the hydraulic system and mechanical parts, causing damage to them.

Further, the worker often depresses the accelerator pedal in an attempt to quickly finish the pushing operation, 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 Therefore, an object of the present invention is to provide a drive control device for a garbage pushing device that can prevent the garbage pushing device from exceeding a predetermined speed even if the engine and hydraulic pump rotate at high speeds above a predetermined speed. .

<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 hydraulic cylinder via the electromagnetic switching valve. A garbage pushing device connected to a hydraulic pump and controlling the switching of the electromagnetic switching valve to extend and retract the hydraulic cylinder, a bypass electromagnetic switching valve that returns a portion of the hydraulic oil from the hydraulic pump to the oil reservoir;
A proximity sensing device detects the rotational speed of the hydraulic pump, and the hydraulic pump rotational speed per unit time and the hydraulic pump rotational speed per unit time created based on a signal representing the hydraulic pump rotational speed output from the proximity sensing device. Compare with the set rotation speed,
If the number of revolutions of the hydraulic pump per unit time is less than the set number of revolutions per unit time, the bypass electromagnetic switching valve is closed, and the number of revolutions of the hydraulic pump per unit time becomes the set number of revolutions per unit time. The present invention is characterized in that a signal control device is provided that opens the bypass electromagnetic switching valve if the number of bypass electromagnetic switching valves is greater than the number.

<Operation> The signal control device counts the signal representing the rotation speed of the hydraulic pump output from the proximity sensing device, compares the counted value with a predetermined rotation speed set in advance, and outputs a signal when they match. Then, the electromagnetic switching valve is operated to extend and retract the hydraulic cylinder, thereby driving the compression pushing plate in a cycle, and the garbage pushing device repeats a predetermined cycle operation according to the rotation speed of the hydraulic pump, thereby increasing the number of cycles per unit time. If the number of revolutions of the hydraulic pump is less than the set number of revolutions per unit time, the bypass electromagnetic switching valve is closed, while if the number of revolutions of the pressure pump per unit time is more than the set number of revolutions per unit time,
The bypass electromagnetic switching valve is opened to return a portion of the hydraulic oil from the hydraulic pump to the oil reservoir, thereby maintaining the dirt pushing device at a predetermined speed or lower.

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

Figure 1 shows a garbage collection vehicle, l is the body frame, 2 is the body frame l
3 is a garbage disposal box installed at the rear of the garbage storage box 2; 4 is a garbage pushing device installed in this garbage disposal box 3; 5 is an operation for switching between pushing and discharging garbage. Switches 6 and 7 are a push switch and a stop switch provided on the outer surface of the garbage storage box 3, and 8 is an accelerator pedal of the garbage collection vehicle.

The garbage pushing device 4 includes a compression pushing plate 41 and a first part that drives the base 41a of the compression pushing plate with a piston rod 4°.
A second hydraulic cylinder 35 and a piston rod 40' drive the tip end 41b of the compression pushing plate through a link 42 and a link 43 whose one end is pivoted 44 to the garbage disposal box 3.
It consists of a hydraulic cylinder of 35 degrees (see FIG. 2), and the structure thereof is 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 on the pivot point 9, and discharges the garbage in the garbage storage box 2 to the outside. . Further, the output of the engine adjusted by the accelerator pedal 8 rotates the hydraulic pump 23 through the drive shaft 22, as shown in FIG. The rotation of the motor is sensed and an electric signal corresponding to the rotation speed is output 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 above hydraulic system is as shown in Figure 5.
A bypass solenoid valve 5I that returns part of the hydraulic oil from the hydraulic pump 23 to the oil reservoir 31 and a throttle valve 52 that adjusts the amount of fluid that returns to the oil reservoir 31 via the bypass solenoid valve 51 are added. , the same constituent members are given the same numbers and their explanations are omitted. In addition, in the electrical system shown on the right side of Figure 2,
24 is the aforementioned proximity sensing device, and 26 is the aforementioned switching control device having the same configuration as that in FIG. 4.

A signal control device IO is provided between the proximity sensing device 24 and the switching control device 26. This signal control device 10 transmits an electrical signal representing the rotation speed of the hydraulic pump manually inputted from the proximity sensing device 24 to a counting circuit L of the control device 26 (see FIG. 4).
Output to. The switching control device 26 is supplied with a DC power source from the terminal (+) via the aforementioned operation switch 5, push switch 6, and normally open stop switch 7, and this DC power is supplied to the discharge device side 14 by the operation switch 5. You can switch to A well-known engine constant rotation device 15 is connected from the DC power supply (+) side to the (-) side between the stop switch 7 and the switching control device 26, and the solenoid 51a of the bypass solenoid valve 51 and the open/close switch 53 are connected. has been done. The constant engine rotation device 15 controls the rotation of the engine at a constant speed so as to provide the optimal hydraulic pump rotation speed for pushing in dust even when the accelerator pedal 8 is not depressed. Further, the opening/closing switch 53 is controlled by the signal control device 10. That is, the signal control device IO compares the count value per unit time of the electric signal representing the rotation speed of the hydraulic pump with the set value inputted from the upper limit rotation speed setting device 11, and if the count value is less than the set value. The open/close switch 53 is opened, and if the count value exceeds the set value, the open/close switch 53 is closed. 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 operation switch 5 is switched to the garbage pushing device side and the push 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 sent to the signal control device I.
The signal is inputted to the counting circuit of the switching control device 26 via O and counted.

The switching control device 26 operates in the same manner as described in FIG.
As a result, the solenoid switching valve 28.28° and the hydraulic cylinder 3
The hydraulic system consisting of 5°, 35°, etc. performs the same operation as described in FIG. 5, and the garbage pushing device 4 repeats a predetermined cycle operation consisting of return-compression-pushing depending on the rotational speed of the hydraulic pump. On the other hand, the upper limit rotational speed setting value of the hydraulic pump is preset in the upper limit rotational speed setting device 11 according to the type of garbage and the request of the operator. Then, the signal control device IO compares the count value per unit time of the electric signal counted by the counting circuit with the set value, and if the count value is less than the set value, the on/off switch 53 is kept open. do.

Therefore, the solenoid 51a is not energized and the bypass solenoid valve 51 remains closed. However, when the operator depresses the accelerator pedal 8, the engine and hydraulic pump 2
3 is rotated at high speed, and when the count value becomes equal to or greater than the set value, the signal control device 10 closes the open/close switch 53 and outputs a signal to the alarm 12. Then, the solenoid 51a is energized, the bypass electromagnetic valve 51 is opened, a portion of the hydraulic oil from the hydraulic pump 23 returns to the oil reservoir 3I, and the pushing device is maintained at a predetermined speed or less. Therefore, there is no danger, and since the pushing device does not stop, there is no reduction in efficiency.

Further, at the same time as this control is performed, the alarm I2 receives an output signal from the signal control device 1O, and notifies with a buzzer or a lamp that the hydraulic pump is rotating at a high speed higher than a set value. In addition, in an emergency, the normally open stop switch 7 can be opened to stop the garbage pushing device 4. Furthermore, 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 storage box 2
The dust inside is discharged to the outside.

In the embodiment described above, since the alarm 12 is provided, the operator can detect when the hydraulic pump rotates at a high speed higher than the set value and the oil from the hydraulic pump 51 is returned to the oil sump through the bypass solenoid valve 51. You can quickly find out if there is one.

In the above embodiment, the rotation speed control of the engine constant rotation device 15 is fixed at a constant speed, but this control speed may be changed in conjunction with the setting value of the upper limit rotation speed setting device 11. . Further, the signal control device IO switches the count value of the electric signal representing the rotation speed of the hydraulic pump to the control device 2.
6, however, a counting circuit may be provided in the signal control device itself.

<Effects of the Invention> As is clear from the above explanation, the drive control device for the garbage pushing device of the present invention has the advantage that the number of rotations of the hydraulic pump per unit time, which is generated in response to the output signal from the proximity sensing device, is The compression push plate is equipped with a signal control device that closes the bypass electromagnetic switching valve when the rotation speed is less than the set rotation speed per unit time, and opens the bypass electromagnetic switching valve when the rotation speed exceeds the set rotation speed per unit time. The device will not operate at a higher speed than the set value, the hydraulic system and mechanical parts of the garbage pushing device will not be strained and damaged, and there will be no personal injury caused by the high speed operation of the garbage pushing device. Since there is no need to stop the pushing device, there is no reduction in efficiency.

[Brief explanation of the drawing]

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 portion of FIG. 3, and FIG. 5 is an operational diagram of the drive control device 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, 23...Hydraulic pump, 24...Proximity sensing device, 26...Switching control device, 28.28'...
・Solenoid switching valve, 35.35°...Hydraulic cylinder, S,, St, S,, S,...Solenoid, 51...
Bypass electromagnetic switching valve, 51a... Solenoid, 52... Throttle valve, 53...
・Open/close switch. Patent applicant Agent: Kyokuto Kaihatsu Kogyo Co., Ltd.
Patent attorney Aoyama Aoyama and 2 others uJ u
J Figure S Figure 4

Claims (1)

[Claims] (1) A garbage pushing device that connects a hydraulic cylinder that drives a compression pushing plate that pushes garbage into a garbage storage box to a hydraulic pump via an electromagnetic switching valve, and controls the switching of the electromagnetic switching valve to cause the hydraulic cylinder to expand and contract. , a bypass electromagnetic switching valve that returns a portion of the hydraulic oil from the hydraulic pump to the oil reservoir; a proximity sensing device that detects the rotation speed of the hydraulic pump; and a rotation of the hydraulic pump 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 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 to be the set number of revolutions per unit time. A signal control device that closes the bypass electromagnetic switching valve if the rotational speed is less than the rotational speed, and opens the bypass electromagnetic switching valve if the rotational speed of the hydraulic pump per unit time is equal to or higher than the set rotational speed per unit time. A drive control device for a garbage pushing device.