JP2006016193A - Refuse-collecting vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refuse-collecting vehicle capable of suppressing the noise when the load of a loading device is increased. <P>SOLUTION: In a loading device to be operated by the hydraulic pressure generated by a hydraulic pump with an electric motor as a driving source, when the load is increased, and the working pressure exceeds a predetermined value, the number of rotation of the electric motor is reduced by a control device. Since the discharge of the hydraulic pump is decreased, increase of the working noise of the hydraulic pump and the loading device when the load is increased is suppressed, and the noise is suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a garbage collection vehicle having a function of efficiently loading garbage such as garbage and oversized garbage.

  The refuse collection vehicle includes a loading device for loading the dust thrown into the dust throwing box at the rear of the vehicle into the dust storage box. For example, in the conventional garbage truck described in Patent Document 1, an electric motor is driven by a battery, hydraulic pressure is generated by a hydraulic pump connected to the electric motor, and the loading device is operated by this hydraulic pressure. The battery is charged by the output voltage of the generator driven by the engine during travel. Moreover, at the time of dust loading, a loading apparatus is operated only by the electric power supply from a battery.

Japanese Utility Model Publication No. 55-164203 (Fig. 2)

In the conventional garbage collection vehicle as described above, for example, when the load on the loading device increases at the end of the dust compression and loading process, the operating noise of the hydraulic pump and the loading device increases, resulting in noise. In particular, when dust is loaded in a quiet residential area in the early morning, such a loud sound is a problem.
In view of the conventional problems as described above, an object of the present invention is to provide a garbage truck that can suppress noise when the load of a loading device increases.

The refuse collection vehicle of the present invention includes a dust container, a dust container box connected to the dust container, an electric motor, a hydraulic pump driven by the electric motor, and a hydraulic pressure of the hydraulic pump. A loading device that performs an operation of loading the dust thrown into the dust bin into the dust storage box, a load detection unit that detects a load equivalent amount indicating a degree of load applied to the loading device, and the electric motor And a control device for reducing the rotation speed of the electric motor when the load equivalent detected by the load detection means exceeds a predetermined value.
In the garbage truck configured as described above, when the load applied to the loading device increases and the load equivalent amount exceeds a predetermined value, the control device reduces the rotation speed of the electric motor. As a result, the discharge amount of the hydraulic pump is reduced, and an increase in operating noise of the hydraulic pump and the loading device when the load is increased is suppressed.

Moreover, in the said garbage collection vehicle, you may provide the switching means which selects a desired value from the predetermined value set to the multistage.
In this case, by selecting a desired value by the switching means, a load equivalent amount (working pressure) for reducing the discharge amount of the hydraulic pump is selected, and loading operation in a plurality of modes is performed with one garbage collection vehicle. It is possible to perform noise suppression suitable for the use situation of the garbage truck.

Further, in the above garbage collection vehicle, the load equivalent amount is the operating pressure, and the control device adjusts the rotation speed of the electric motor so as to keep the output of the hydraulic pump constant according to the increase of the operating pressure exceeding a predetermined value. It may be gradually reduced.
In this case, the hydraulic pump keeps the output constant while gradually decreasing the discharge amount. Therefore, the impact sound of the loading device due to the sudden change in output can be prevented.

  According to the refuse collection vehicle of the present invention, when the load applied to the loading device increases and the load equivalent amount exceeds a predetermined value, the control device reduces the rotation speed of the electric motor. As a result, the discharge amount of the hydraulic pump decreases, so that an increase in the operating noise of the hydraulic pump and the loading device when the load increases is suppressed, and noise can be suppressed.

  FIG. 1 is a side sectional view showing a rear portion of a press-type garbage truck according to an embodiment of the present invention. In the figure, the refuse collection vehicle 1 includes a dust storage box 2 and a dust input box 3 connected to the rear part thereof. Behind the dust input box 3 is provided a lid 3b that slides up and down the input port 3a into which the dust is input. In addition, an opening 3 d for loading the dust into the dust storage box 2 is provided at the lower front portion of the dust throwing box 3.

  Next, the loading device 50 provided in the garbage throwing box 3 will be described. First, left and right side walls 3c of the dust box 3 are provided with guide rails 4 extending obliquely up and down, and a pair of left and right rollers 6 attached to the slider 5 are obliquely up and down inside the guide rails 4. Can move. The slider 5 is formed by connecting the left and right members having a side shape as shown in the drawing by a plate or the like (not shown) extending in the vehicle width direction. Further, a pushing plate 8 is rotatably attached to the lower end portion of the slider 5 via a pin 7. The pushing plate 8 is also integrally formed by connecting the left and right side members shown in the figure with a plate or the like (not shown) extending in the vehicle width direction.

  On the other hand, the cylinder side end of the push cylinder 9 is attached to the side wall 3 c by a pin 10, and the piston side end is connected to the upper end of the slider 5 by a pin 11. On the other hand, the cylinder side end of the press cylinder 12 is connected to the pushing plate 8 by a pin 13, and the piston side end is connected to the upper end of the slider 5 by the pin 11. Along with the pushing plate 8, the slider 5 rises obliquely by the extension operation of the push cylinder 9, and descends obliquely by the contraction operation. As a result, the slider 5 can reciprocate corresponding to primary compression and push-in described later. Further, the pushing plate 8 is rotated clockwise around the pin 7 by the extension operation of the press cylinder 12, and is rotated counterclockwise by the contraction operation. Thereby, the pushing plate 8 can be reciprocally rotated corresponding to reversal and secondary compression described later.

  2A is an operation explanatory view in which only the pushing plate 8, the push cylinder 9 and the press cylinder 12 which are the main parts of the loading device 50 are extracted from FIG. 1 (however, in order to make the drawing easy to see) 9 is slightly shifted.) The pushing plate 8 performs the “reverse” stroke by the contraction operation of the press cylinder 12 with the position shown in (a) as the original position, and enters the state shown in (b). Next, the push plate 8 performs a “primary compression” process by the contraction operation of the push cylinder 9 and is in a state shown in FIG. Subsequently, the pushing plate 8 performs a “secondary compression” process by the extension operation of the press cylinder 12 and is in a state shown in FIG. Finally, the pushing plate 8 performs a “pushing” stroke by the push cylinder 9 extending, and returns to the state shown in FIG. As the push cylinder 9 and the press cylinder 12 operate alternately in this way, the pushing plate 8 performs a stroke operation (reversing, primary compression, secondary compression, pushing). As shown in the drawing, the distal end portion 8a of the pushing plate 8 draws a closed shape in which the operation locus connects four points.

  In the vicinity of the push cylinder 9 and the press cylinder 12, proximity switches (14, 15, 16, and 17) are provided for detecting that their expansion and contraction operations have reached the extension end and the contraction end, respectively. The first proximity switch 14 detects that the operation of the push cylinder 9 has reached the extended end. The second proximity switch 15 detects that the operation has reached the contracted end by detecting the dog 12 a attached to the press cylinder 12. The third proximity switch 16 detects that the operation of the push cylinder 9 has reached the contracted end. The fourth proximity switch 17 detects that the operation of the press cylinder 12 has reached the extended end. The first proximity switch 14 and the third proximity switch 16 are fixedly attached to the dust box 3, but the second proximity switch 15 and the fourth proximity switch 17 are attached to the slider 5 side. The push cylinder 9 moves with the expansion and contraction operation.

  FIG. 3 is a hydraulic circuit diagram relating to the push cylinder 9 and the press cylinder 12. The hydraulic circuit includes a tank 21, a hydraulic pump 22, a back pressure valve 23, a push cylinder solenoid valve 24, a press cylinder solenoid valve 25, relief valves 26 and 27, a pressure reducing valve 28, check valves 29 to 32, a filter 33, 34 and the pressure sensor 51 are connected as shown in the figure. When the pushing plate 8 is stopped at the original position ((a) in FIG. 2), the cylinders 9 and 12 are in the extended state, and the electromagnetic valves 24 and 25 are in the neutral position. When the solenoid 25s of the press cylinder solenoid valve 25 is energized, "reverse", when the solenoid 25e is energized, "secondary compression", and when the solenoid 24s of the push cylinder solenoid valve 24 is energized, "primary compression", When the solenoid 24e is excited, each operation of “push” is performed. The pressure sensor 51 constantly detects the operating pressure of the discharge oil passage of the hydraulic pump 22, and provides the detection output to a controller (19) described later. Note that a swing cylinder for opening the dust container 2 by rotating the dust container 3 upward, a discharge cylinder for pushing out the dust stored in the dust container 2, and the like are also connected to the hydraulic circuit. The description is omitted.

  FIG. 4 is a block diagram illustrating a configuration of the loading control device 20 in the loading device 50. Outputs of the first to fourth proximity switches 14 to 17 are input to a controller 19 including a CPU, a memory, an interface circuit, and the like. A command such as a loading operation start command is input to the controller 19 from the operation switch 18. The push cylinder solenoid valve 24 and the press cylinder solenoid valve 25 are excited by the controller 19.

  Next, the system configuration of the garbage truck that drives the hydraulic pump 22 will be described with reference to the block diagram of FIG. In the figure, a generator 53 is connected to the engine 52 of the garbage truck. The output voltage of the generator 53 is supplied to an inverter 55 (including a gate control circuit) via a rectifier 54. An AC motor (induction motor) 56 for driving the hydraulic pump 22 is connected to the inverter 55. The AC motor 56 includes a rotation speed sensor 57, and the output is input to the controller 19 described above. The output of the pressure sensor 51 and the signal of the changeover switch 58 are also input to the controller 19. Based on the output of the pressure sensor 51 and the signal of the changeover switch 58, the controller 19 and the inverter 55 use a motor control device 59 that controls the rotational speed of the AC motor 56 while using the output of the rotational speed sensor 57 as a feedback signal. It is composed.

  The changeover switch 58 is provided in a switch box 60 as shown in FIG. 6 together with other switches and lamps. The switch box 60 is provided, for example, in a driver's seat (cab). The changeover switch 58 can be switched to, for example, three positions of “low output”, “normal”, and “high output”, and any one position can be selected.

Next, the operation of the controller 19 will be described with reference to the PQ diagram of FIG. In FIG. 7, the horizontal axis represents the operating pressure P [Pa] detected by the pressure sensor 51 (FIGS. 3 and 5), and the vertical axis represents the discharge amount Q [m ³ / sec] of the hydraulic pump 22. The discharge amount Q is proportional to the rotational speed of the hydraulic pump 22, that is, the rotational speed of the AC motor 56. The PQ diagram has three modes, a low output mode, a normal mode, and a high output mode. By selecting one of the modes with the changeover switch 58, the controller 19 follows the PQ diagram of the selected mode. The rotational speed is controlled as follows.

  In FIG. 5, the loading of the dust is performed with the engine 52 in an idling state. The output voltage (AC) of the generator 53 driven by the engine 52 is converted into a DC voltage by the rectifier 54 and supplied to the inverter 55. A control signal to the inverter 55 is given from the controller 19 based on the outputs of the pressure sensor 51, the rotation speed sensor 57 and the changeover switch 58. Here, assuming that the normal mode is selected by the changeover switch 58, the controller 19 performs the rotational speed control so as to follow the PQ diagram of the normal mode of FIG.

Specifically, the operating pressure represented by the signal input from the pressure sensor 51 is P [Pa], and the rotational speed N [rpm] represented by the signal input from the rotational speed sensor 57 is converted into a discharge amount. Assuming that Q [m ³ / sec], when P ≦ P2 (10 MPa), Q = Q1 (0.83 × 10 ⁻³ m ³ / sec (50 liters / min)). When the operating pressure P exceeds P2, the discharge amount (rotation speed) is gradually decreased as the operating pressure P increases. In this case, “gradual decrease” means that the discharge amount (rotation speed) is decreased in inverse proportion to the increase in the operating pressure P, whereby the output PQ while the discharge amount is decreasing becomes a constant value.

That is, the output when P = P2 is P2 · Q1, which is the following value from the numerical values shown in the figure. This is also the maximum output in normal mode.
P2 · Q1 = 10 × 10 ⁶ × 0.83 × 10 ⁻³
= 8.3 × 10 ³ [W] = 8.3 [kW]
Therefore, Q when P2 <P is
Q = (8.3 × 10 ³ ) / P. . . (1)
The motor control device 59 rotates the AC motor 56 at a rotational speed N corresponding to Q in the equation (1). And the discharge amount Q2 when the operating pressure P reaches P3 (18 MPa) is obtained from the equation (1):
Q2 = (8.3 × 10 ³ ) / (18 × 10 ⁶ )
= 0.46 × 10 ⁻³ [m ³ / sec] = 28 [liter / min]
It becomes. However, when the operating pressure P reaches P3 (18 MPa), the controller 19 stops the AC motor 56.
Note that the output PQ corresponds to the output of the AC motor 56 if the mechanical loss of the hydraulic pump 22 is ignored.

  Such control increases the load on the push cylinder 9 and the press cylinder 12 during the dust compression (primary compression, secondary compression) and the pushing process (especially at the end), and the operating pressure P of the discharge oil passage of the hydraulic pump 22 is increased. When the pressure exceeds 10 MPa, the rotational speed of the AC motor 56 is reduced and the discharge amount is reduced. Thereby, an increase in operating noise of the hydraulic pump 22 and the loading device 50 is suppressed, and generation of noise can be suppressed.

On the other hand, when the low output mode is selected by the changeover switch 58, when P ≦ P1 (5 MPa), Q = Q1 (0.83 × 10 ⁻³ m ³ / second (50 liters / minute)). . And if the operating pressure P exceeds P1, according to the increase in the operating pressure P, discharge amount (rotation speed) will be decreased gradually. In this case, “gradual decrease” is to decrease the discharge amount (rotation speed) in inverse proportion to the increase in the operating pressure P, as in the normal mode, whereby the output PQ while the discharge amount is decreasing becomes a constant value. .

That is, the output when P = P1 is P1 · Q1, which is the following value from the numerical values shown in the figure. This is also the maximum power in the low power mode.
P1 · Q1 = 5 × 10 ⁶ × 0.83 × 10 ⁻³
= 4.2 × 10 ³ [W] = 4.2 [kW]
Therefore, Q when P1 <P is
Q = (4.2 × 10 ³ ) / P. . . (2)
The motor control device 59 rotates the AC motor 56 at a rotational speed N corresponding to Q in the equation (2). And the discharge amount Q3 when the operating pressure P reaches P3 (18 MPa) is obtained from the equation (2):
Q3 = (4.2 × 10 ³ ) / (18 × 10 ⁶ )
= 0.23 × 10 ⁻³ [m ³ / sec] = 14 [liter / min]
It becomes. However, when the operating pressure P reaches P3 (18 MPa), the controller 19 stops the AC motor 56.

  By such control, the load on the push cylinder 9 and the press cylinder 12 increases during the process of dust compression (primary compression, secondary compression) and pushing, and the operating pressure P of the discharge oil passage of the hydraulic pump 22 exceeds 5 MPa. And the rotation speed of the AC motor 56 is lowered, and the discharge amount is lowered. As a result, the hydraulic pump 22 is in a “topped” state at a lower output than in the normal mode. Therefore, an increase in operating noise of the hydraulic pump 22 and the loading device 50 is suppressed, and generation of noise can be suppressed.

On the other hand, if the high output mode is selected by the changeover switch 58, the discharge amount Q1 and the corresponding rotation speed are maintained even when the operating pressure P exceeds P1 and P2, and the maximum output P3 · Q1 is shown in the figure. It becomes the following value from the numerical value shown.
P3 · Q1 = 18 × 10 ⁶ × 0.83 × 10 ⁻³
= 15 × 10 ³ [W] = 15 [kW]
When the operating pressure P reaches P3 (18 MPa), the controller 19 stops the AC motor 56.
By such control, even if the load of the push cylinder 9 and the press cylinder 12 increases during the process of dust compression (primary compression, secondary compression) and the pushing process, and the operating pressure P of the discharge oil passage of the hydraulic pump 22 increases. The rotation speed and the discharge amount are maintained until P3 is reached. Thereby, the hydraulic pump 22 and the loading device 50 have a higher output than the normal mode when viewed from the whole stroke, and can load quickly. However, instead, an increase in operating noise when the load increases is unavoidable.

  By properly using each of the above modes, it is possible to select an operation according to the location, type of garbage, etc. when loading. For example, for loading normal garbage (such as garbage) early in the morning or at night, the low output mode can be selected to perform loading with priority on noise suppression. For normal garbage loading during the daytime, the normal mode can be selected to achieve a certain level of noise suppression and efficiency. On the other hand, in the case of loading in a place with a lot of ambient noise such as a factory zone, it is not necessary to worry about the operating noise of loading, so it is possible to select the high output mode and perform loading quickly. it can. Also, in the case of loading bulky garbage during the daytime, the bulky garbage can be reliably compressed and loaded by selecting the high output mode. In this way, by selecting the load equivalent amount (operating pressure) for reducing the discharge amount of the hydraulic pump 22 by the changeover switch 58, the multi-mode loading operation is performed by one garbage collection vehicle, and the dust collection is performed. Noise suppression suitable for the usage situation of the car can be performed.

The PQ diagram may be as shown in FIG. In this case, the high output mode is the same as that in FIG. 7, but the discharge amount (rotation speed) is decreased in the normal mode and the low output mode. That is, in the normal mode, when the operating pressure P exceeds P2, the discharge amount Q decreases to Q2 at once, and thereafter Q2 is maintained until it reaches P3. Further, in the low output mode, when the operating pressure P exceeds P1, the discharge amount Q decreases to Q3 all at once, and thereafter Q3 is maintained until it reaches P3. Even if the rotational speed control is performed according to such a PQ diagram, an effect of suppressing an increase in operating noise due to an increase in the load of the loading device 50 can be obtained.
However, as shown in the PQ diagram of FIG. 8, when the discharge amount is rapidly reduced, an impact sound is generated in the loading device 50 due to a sudden change in output. On the other hand, if the output during the discharge amount reduction is kept constant as shown in the PQ diagram of FIG. 7, the generation of the impact sound can be prevented.

  Next, the system configuration of the garbage truck that drives the hydraulic pump 22 will be described with reference to the block diagram of FIG. 9 differs from FIG. 5 in that instead of taking a signal from the pressure sensor 51 (FIG. 5) into the controller 19, a current sensor 62 is provided in the secondary side electric circuit of the inverter 55, and an AC motor 56 as its output signal is provided. The input current is taken into the controller 19. The operating pressure of the loading device 50 becomes a load of the hydraulic pump 22, which is a mechanical load of the AC motor 56. Further, the mechanical load of the AC motor 56 and the input current have a predetermined correlation. Therefore, the input current to the AC motor 56 can be handled as a load (operating pressure) equivalent amount of the loading device 50. Therefore, when the input current corresponding to each of the operating pressures P1, P2, and P3 is detected by the current sensor 62, the controller 19 controls the rotational speed of the AC motor 56, for example, according to the PQ diagram of FIG. You can do it.

In each of the above embodiments, the AC motor 56 is used. However, the present invention is not limited to an AC motor, and any electric motor can be used. For example, a brushless DC motor is used, and a voltage / current is supplied by an inverter 55 driven by the controller 19. It is also possible to control the number of revolutions of the motor by changing.
Moreover, although the loading apparatus in the said embodiment is a press type, even if it is a rotary plate type loading apparatus, it can control the rotation speed of a motor similarly and can suppress the increase in an operating noise.
Further, the pressure setting in the PQ diagrams shown in FIGS. 5 and 8 is a three-stage setting of P1 (5 MPa), P2 (10 MPa), and P3 (18 MPa), but this is only an example, and the set value and the number of setting steps Can be selected as needed.

In each of the above embodiments, the discharge amount is handled as an amount corresponding to the rotation speed of the AC motor, and the rotation speed sensor 57 detects the rotation speed corresponding to the discharge amount. However, instead of the rotation speed sensor, the hydraulic pump 22 A flow rate sensor that directly detects the discharge amount may be provided, and a desired discharge amount may be obtained by controlling the number of rotations of the motor while using the output as a feedback signal.
In each of the above embodiments, the engine is driven and power is supplied from the generator. However, it is also possible to stop the engine and supply power to the motor control device 59 from a battery (not shown).

In the above embodiments, the changeover switch 58 is used. However, not only the switch but also various changeover means can be used. For example, if only the time zone is switched, the mode can be automatically switched using a 24-hour timer.
The controller 19 may be provided separately for a device for controlling the rotational speed of the AC motor 56 and a device for controlling the loading device.

It is a sectional side view which shows the rear part of the press-type garbage collection vehicle by one Example of this invention. It is operation | movement explanatory drawing which extracted only the pushing board, push cylinder, and press cylinder which are the principal parts of the loading apparatus from FIG. It is a hydraulic circuit diagram regarding the push cylinder and the press cylinder. It is a block diagram which shows the structure of the loading control apparatus in a loading apparatus. It is a block diagram about the system configuration | structure of the garbage truck which drives a hydraulic pump. It is a front view of a switch box. It is a PQ diagram which shows a control characteristic. It is another PQ diagram. It is a block diagram about the other system structure of the refuse collection vehicle which drives a hydraulic pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dust collection truck 2 Dust storage box 3 Dust input box 22 Hydraulic pump 50 Loading device 51 Pressure sensor (load detection means)
56 AC motor 58 selector switch (switching means)
59 Motor control device (control device)

Claims (3)

A dust bin,
A dust input box connected to the dust container;
An electric motor;
A hydraulic pump driven by the electric motor;
A loading device that performs an operation of loading the dust thrown into the dust throwing box into the dust containing box by the hydraulic pressure of the hydraulic pump;
Load detecting means for detecting a load equivalent amount representing the degree of load applied to the loading device;
A garbage collection vehicle comprising: a control device that controls the number of revolutions of the electric motor and reduces the number of revolutions of the electric motor when a load equivalent detected by the load detection unit exceeds a predetermined value. .   2. A garbage collection vehicle according to claim 1, further comprising switching means for selecting a desired value from the predetermined values set in a plurality of stages.   The load equivalent amount is an operating pressure, and the control device gradually decreases the rotational speed of the electric motor so as to keep the output of the hydraulic pump constant according to the increase of the operating pressure exceeding the predetermined value. Item 1. A garbage collection vehicle according to item 1.

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