JP6575683B2 - Hydraulic control device - Google Patents

Description

  The present invention relates to a motor for supplying power to a drive target, a hydraulic mechanism including a hydraulic pump for receiving power from the motor, and driving the drive target by receiving supply of hydraulic pressure from the hydraulic mechanism. The present invention relates to a hydraulic pressure control device including an actuator for performing the above operation.

  2. Description of the Related Art Conventionally, as a hydraulic control device mainly mounted on an industrial vehicle, such as a gate device mounted on the rear part of a load carrying truck, one having the following configuration has been widely adopted. That is, this includes a motor that supplies power to a driving object such as a cargo bed, a hydraulic mechanism that includes a hydraulic pump that receives hydraulic power from the motor and supplies hydraulic pressure, And a plurality of actuators for receiving a pressure supply and driving an object to be driven such as a cargo bed. The hydraulic pressure control device further includes a switch called a contactor for turning on / off an electric circuit between a power source and the motor, and a control valve for controlling the supply of hydraulic fluid to a plurality of actuators. The driver operates the power supply operation unit for turning the contactor on and off, and the valve operation unit for switching the state of the control valve so as to switch the direction of tilting operation and lifting operation of the loading platform. The cargo handling operation and the like are performed by (see, for example, Patent Document 1). Here, when carrying out the cargo handling work, control for gradually increasing the rotational speed of the motor toward the target rotational speed immediately after starting the cargo handling work or control for gradually reducing the rotational speed of the motor immediately before the completion of the cargo handling work is performed. It has been broken.

  By the way, in this type of conventional hydraulic control device, the target rotational speed is constant, but the motor and the hydraulic pump are kept at a constant target rotational speed, especially in a low noise environment such as a residential area at night. When rotating, there is a problem that noise leaking to the outside may be too large. As measures for solving this problem, it is conceivable to store the hydraulic control device inside a highly sealed housing, or to dispose more soundproofing material inside the housing storing the hydraulic control device. However, it is difficult to realize these measures that require a highly sealed housing and a large amount of soundproofing materials at a low cost, and suppress noise leaking to the outside regardless of the housing sealingness and the amount of soundproofing material. Measures are needed for this purpose.

  On the other hand, in a noisy environment, even if the noise generated from the fluid pressure control device is large, there is relatively little adverse effect on the outside, so the supply volume of hydraulic fluid supplied to the actuator is increased per unit time for cargo handling work. Although there is a need for quick operation, it has been difficult for such a conventional hydraulic control device to meet such a need.

  The above-mentioned problems are not limited to the gate device mounted on the rear part of the load carrying truck, but the wing vehicle that opens and closes the side door of the load carrying truck, or the inside of a factory or warehouse where there are houses around, for example, Includes a hydraulic control device for performing the lifting and lowering operation of the loading platform of the cargo handling device, such as a hydraulic control device used for raising and lowering the loading platform of the forklift used in the vicinity, and a hydraulic pump that receives power from the motor It exists in all hydraulic control devices equipped with a hydraulic mechanism.

Japanese Patent No. 4849995

  The present invention pays attention to the above points, and in order to reduce noise leaking outside from such a hydraulic control device in an environment where noise is low, the degree of sealing of the housing housing the hydraulic control device and the soundproofing inside the housing Fluid pressure control device that enables quick operation without using a special device without depending on the amount of material and using such a fluid pressure control device in a noisy environment. It aims at realizing.

In order to solve the above problems, the hydraulic control device according to the invention of claim 1 has a configuration as described below. That is, the hydraulic control apparatus according to the invention of claim 1 supplies a hydraulic pressure by receiving a supply of power from the motor and a motor for supplying power to the driven object while operating while maintaining the target rotational speed. A hydraulic mechanism including a hydraulic pump; one or a plurality of actuators that receive a supply of hydraulic pressure from the hydraulic mechanism to drive an object to be driven; a noise detection element that detects the magnitude of noise; and the noise detection And a control unit that performs control to increase the target rotational speed of the motor as the noise indicated by the signal output from the element increases.

  In this case, when the noise is low, the target rotational speed of the motor can be lowered, and the noise generated from the motor and the hydraulic pump can be reduced. Therefore, without covering the motor and hydraulic pump of such a hydraulic pressure control device with a highly sealed housing or providing a large amount of soundproofing material inside the housing, it leaks to the outside in a low noise environment. Noise can be reduced. On the other hand, when the noise is low, the target rotational speed of the motor is increased and a large amount of hydraulic fluid is supplied from the hydraulic pump to the hydraulic circuit and actuator, so that the operation can be performed quickly.

  As a preferred mode of use of such a hydraulic pressure control device, there is one in which the driven object is a cargo bed.

Further, as an aspect for easily realizing the above-described hydraulic pressure control device, the motor is a brushless DC motor.
On the other hand, the hydraulic control apparatus according to the invention of claim 4 has a configuration as described below. That is, a hydraulic control device according to a fourth aspect of the present invention includes a hydraulic mechanism including a motor that supplies power to a drive target, a hydraulic pump that receives hydraulic power from the motor and supplies hydraulic pressure, One or a plurality of actuators for receiving a hydraulic pressure supplied from a hydraulic mechanism to drive a driven object, a noise detection element for detecting the magnitude of noise, and a noise output from the noise detection element are large. A control unit that increases the target rotational speed of the motor as it becomes, and controls to decrease the rotational speed immediately after the start of operation and increase the rotational speed as it approaches the target rotational speed. .
If it is such, compared with the case where the aspect which changes a rotation speed linearly is employ | adopted, a rotation speed is comparatively small, without changing the length of the period from an operation start to reaching a target rotation speed. The period can be made longer.

  According to the present invention, in order to reduce noise leaking outside from such a hydraulic control device in an environment with low noise, the degree of sealing of the housing housing the hydraulic control device and the amount of soundproofing material inside the housing are reduced. It is possible to realize a quick operation using such a hydraulic control device in an environment with a high noise level without requiring a special device.

Schematic which shows the cargo handling apparatus which concerns on one Embodiment of this invention. Schematic which shows the hydraulic-pressure control apparatus which concerns on the same embodiment. Schematic which shows the control part of the hydraulic-pressure control apparatus which concerns on the same embodiment. The flowchart which shows the schematic procedure of the control which the control part which concerns on the same embodiment performs. Action explanatory drawing which shows the effect | action by control which the control part which concerns on the same embodiment performs.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the tailgate lift of the present embodiment is provided at the rear part of a vehicle such as a truck. The tailgate lift is a tailgate plate 1 as a driving object supported so as to be swingable and vertically movable, and a tail. An actuator 2 that drives the gate plate 1 and a hydraulic circuit 3 that supplies hydraulic fluid to the actuator 2 are provided. The actuator 2 and the hydraulic circuit 3 constitute a hydraulic control device of the present invention for driving the tailgate plate 1.

  As shown in FIG. 1, the tailgate plate 1 is supported on the distal end portion of the support arm 4 via a rotary shaft 11 and can swing around the rotary shaft 11. The base end portion of the support arm 4 is supported by the vehicle via a horizontal support shaft 41, and rotates around the horizontal support shaft 41 between the open position shown by the one-dot chain line in FIG. 1 and the closed position shown by the solid line in FIG. Is swingable. The tailgate plate 1 rotates with respect to the support arm 4 to perform a tilting operation that changes its posture, and the support arm 4 rotates with respect to the vehicle to adjust the height position of the tailgate plate 1 as a whole. Perform the ascending / descending operation to be changed.

  As shown in FIG. 1, the actuator 2 includes hydraulic cylinders 21 and 22 that drive the tailgate plate 1, a hydraulic pump 23 that supplies hydraulic fluid to the hydraulic cylinders 21 and 22, and a hydraulic pump 23. The motor 24 as a power source is used as an element. The hydraulic cylinders 21 and 22 include an opening / closing hydraulic cylinder 21 that causes a tilting operation of the tailgate plate 1 and an elevating hydraulic cylinder 22 that causes an upward / downward movement of the tailgate plate 1. The opening / closing hydraulic cylinder 21 is pivotally attached to the tailgate plate 1 and the rear part of the vehicle via pins 211 and 212, and the lifting hydraulic cylinder 22 is connected to the rear part of the vehicle and the support arm 4 via pins 221 and 222. It is attached to each of them. With the opening / closing hydraulic cylinder 21 maintained at a predetermined length and a parallelogram four-bar linkage mechanism having the pins 211 and 212, the rotating shaft 11 and the horizontal support shaft 41 as apexes, the tailgate plate 1 is substantially horizontal. Take a posture. In this state, the tailgate plate 1 is raised / lowered by expanding / contracting the lifting / lowering hydraulic cylinder 22. Further, the angle of the tailgate plate 1 is changed by keeping the lifting hydraulic cylinder 22 at a predetermined length and extending and closing the opening / closing hydraulic cylinder 21. Further, the motor 24 of the present embodiment is a brushless DC motor that receives supply of a three-phase AC current.

  As schematically shown in FIG. 2, the hydraulic circuit 3 is arranged on the flow path that connects the hydraulic fluid tank 5 that stores the hydraulic fluid and the hydraulic cylinders 21 and 22, and controls the flow of the hydraulic fluid. Solenoid valves 321, 322, and 323 are accommodated in the manifold 35. The hydraulic pump 23 receiving the driving force from the motor 24 discharges the hydraulic fluid, and the hydraulic fluid is supplied to the hydraulic cylinder 21 for opening and closing through the flow paths 301, 302, and 308. Further, the fluid is supplied to the lifting hydraulic cylinder 22 through the flow paths 301 and 303. The first and second solenoid valves 321 and 322 are all closed at the normal time when the tail gate plate 1 is not hydraulically driven using the motor 24 and the hydraulic pump 23. The third solenoid valve 323 is in an open state during the steady state.

  When the tailgate plate 1 is in the uppermost position and is in a substantially horizontal open position (indicated by a one-dot chain line in FIG. 1), the open / close hydraulic cylinder 21 contracts and the lift hydraulic cylinder 22 extends. . When the tailgate plate 1 is raised and closed from this state, the first solenoid valve 321 is opened while the hydraulic pump 23 is operated, and the hydraulic fluid is supplied to the open / close hydraulic cylinder 21 to advance the piston. . Conversely, when the tailgate plate 1 in the closed position (shown by a solid line in FIG. 1) is tilted and opened, the second solenoid valve 322 is opened, and the hydraulic fluid in the open / close hydraulic cylinder 21 flows. The piston is retreated by flowing down to the tank 5 through the paths 304, 305, and 306. Incidentally, when the tailgate plate 1 at the uppermost position is lowered, the third solenoid valve 323 is opened, and the working fluid in the lifting hydraulic cylinder 22 is caused to flow down through the flow paths 307 and 306. Reference numerals 331, 332, and 333 denote first to third filters disposed on the upstream side of the first to third solenoid valves 321, 322, and 323, respectively. Reference numeral 34 denotes a flow regulator which is disposed on the downstream side of the third solenoid valve 323 and is provided to adjust the amount of hydraulic fluid flowing out from the lifting hydraulic cylinder 22. The manifold 35, the hydraulic pump 23, the motor 24, and a control unit 7 to be described later are housed in a housing H.

  The motor 24 is connected with a control unit 7, and the control unit 7 controls the motor 24 and the first to third solenoid valves 321 to 323.

  As schematically shown in FIG. 3, the control unit 7 converts the DC current from the battery B to a three-phase AC current into a microcomputer system including a CPU 7a, a main memory 7b, an external storage device 7c, an input / output interface 7d, and the like. And an inverter 7e that converts and supplies it to the motor 24. The input / output interface 7d includes the inverter 7e, an operation switch 7f operated by a user, a microphone 7g that is a noise detection element, and a proximity sensor 7h for detecting that the tailgate plate 1 has approached the end of operation, and First to third solenoid valves 321 to 323 are connected. The operation input device 7f includes, for example, an ascending button and a descending button, and the user can instruct that the tailgate plate 1 should be raised, lowered, opened, or closed by pressing any button. . Specifically, when the operation input device 7f accepts an operation, a program for causing the actuator 2 and the hydraulic circuit 3 to perform an operation corresponding to the operation is stored in the external storage device 7c. By reading the program into the main memory 7b and being executed by the CPU 7a, the hydraulic pump 23, the electric motor 24, and the first to third solenoid valves 321 to 323 are caused to perform the following operations. That is, when a button for raising the tailgate plate 1 is pressed, the electric motor 24 is operated to drive the hydraulic pump 23 and all the first to third solenoid valves 321 to 323 are activated. A valve control signal c is issued so as to be in the closed state. When a button for lowering the tailgate plate 1 is pressed, a valve control signal c is issued so that only the third solenoid valve 323 is opened. When a button for closing the tailgate plate 1 is pressed, the electric motor 24 is operated to drive the hydraulic pump 23, and the valve control is performed so that only the first solenoid valve 321 is opened. Issue signal c. When a button for opening the tailgate plate 1 is pressed, a valve control signal c is issued so that only the second solenoid valve 322 is opened. From the microphone 7g, a noise signal b indicating the level of noise is output to the input / output interface 7d.

  The external storage device 7c has a built-in signal generation program for generating a rotation speed control signal d to be output to the inverter 7e so as to accelerate or decelerate the rotation speed of the motor 24. When the CPU 7a reads the data into the main memory 7b and executes it, the rotation speed control signal d is output to the inverter 7e through the output interface 7d. The inverter 7e receives this rotational speed control signal d and controls the frequency and voltage of the three-phase alternating current supplied to the motor 24 to accelerate or decelerate the rotation of the motor 24.

  Thus, the external storage device 7c has a target rotational speed determination program for determining the target rotational speed using the noise level detected by the microphone 7g as a parameter, and the rotational speed of the motor 24 at the start of the operation of the tailgate plate 1. Start control program for accelerating the motor toward the target rotational speed, and slow stop control program for decelerating the rotational speed of the motor 24 toward 0 when it is detected that the tailgate plate 1 has reached the vicinity of the end of operation. And built-in.

  Here, in the target rotational speed determination program, the target rotational speed becomes higher as the noise increases, in other words, the target rotational speed becomes lower as the noise decreases. Is set to More specifically, when the noise level is below the first threshold (hereinafter referred to as “the noise level is in the first region”), the target rotational speed is set to the first value. I am doing so. In the following, the second, third and fourth threshold values are set in order from the smallest in terms of noise magnitude, and the noise magnitude is greater than or equal to the first threshold value and below the second threshold value (hereinafter referred to as “noise level”). In the case where the magnitude is in the second region), the target rotational speed is set to a second value larger than the first value. Hereinafter, when the noise level is equal to or higher than the second threshold value and lower than the third threshold value (hereinafter referred to as “the noise level is in the third region”), and when the noise level is equal to or higher than the third threshold value, the fourth threshold value is set. (Hereinafter referred to as “the noise level is in the fourth region”), the target rotational speed is set to a third value greater than the second value and a third value, respectively. A large fourth value is set. When the noise level is greater than or equal to the fourth threshold value (hereinafter referred to as “the noise level is in the fifth region”), the target rotational speed is set to a value greater than the fourth value. A value of 5 is set. In the present embodiment, the first to fourth threshold values of the noise level are set to 42.5 dB, 47.5 dB, 52.5 dB, and 57.5 dB, respectively. On the other hand, the first to fifth values of the target rotational speed are set to 1500 rpm, 1750 rpm, 2000 rpm, 2500 rpm, and 3000 rpm, respectively.

  As the control in the slow start control program and the slow stop control program, well-known controls are used for this type of hydraulic control device.

  Hereinafter, a schematic procedure of control performed by the control unit 7 will be described with reference to FIG. 4 which is a flowchart.

  First, the level of noise indicated by the noise signal b is detected (ST1), and the target rotational speed is determined using the detected level of noise as a parameter (ST2). Then, the rotational speed of the motor 24 is gradually increased toward the target rotational speed determined in step ST2 (ST3), and after the rotational speed of the motor 24 reaches the target rotational speed, the rotational speed of the motor 24 is changed to the target rotational speed. Keep the number (ST4). When the proximity sensor 7h detects that the tailgate plate 1 has reached a predetermined position near the operation end, that is, when the proximity signal a indicating that the tailgate plate 1 has approached is output from the proximity sensor 7h ( ST5) Control is performed to gradually reduce the rotational speed of the motor 24 toward 0, that is, to stop the motor 24 (ST6).

  According to the control of the present embodiment, as shown in FIG. 5, when the noise level is in the first region (for example, 40 dB), the target rotational speed is set as shown by the thin solid line in FIG. The first value (1500 rpm) is set. Further, when the noise level is in the second region (for example, 45 dB), the target rotational speed is set to the second value (1750 rpm), as indicated by the two-dot chain line in FIG. Hereinafter, when the noise level is in the third, fourth, or fifth region (for example, 50 dB, 55 dB, or 60 dB), the target rotation is indicated by the alternate long and short dashed line, broken line, and thick solid line, respectively. The numbers are set to the third, fourth or fifth values (2000 rpm, 2500 rpm or 3000 rpm), respectively. Then, the rotational speed of the motor 24 gradually increases toward the set target rotational speed. That is, as the noise increases, the motor 24 is operated at a higher rotational speed. In other words, the motor 24 is operated at a lower rotational speed as the noise becomes smaller.

  That is, according to the configuration of this embodiment, when the noise is low, the target rotational speed of the motor 24 can be lowered, and the noise generated from the motor 24 and the hydraulic pump 23 can be reduced. Therefore, it is possible to reduce the noise leaking to the outside in a low noise environment without covering the motor 24 and the hydraulic pump 23 with a highly sealed housing or arranging a large amount of soundproofing material inside the housing. be able to. On the contrary, when the noise is loud, the target rotational speed of the motor 24 is increased and a large amount of hydraulic fluid is supplied from the hydraulic pump 23 to the hydraulic circuit 3 and the actuator 2 without making a special device easy. You can work quickly.

  Further, since a brushless DC motor is employed as the motor 24, the number of revolutions of the motor 24 can be easily controlled using an inverter.

  The present invention is not limited to the embodiment described above.

  For example, the driving object is not limited to the tailgate plate mounted on the rear part of the vehicle, but may be another type of loading platform such as a loading platform of a forklift. Further, the object to be driven is not limited to the cargo bed, but any wing vehicle that opens and closes the side door of the cargo carrying truck, as long as it is driven by an actuator that operates by receiving hydraulic pressure supplied from the hydraulic mechanism. It may be a thing.

  In the above-described embodiment, a brushless DC motor is used as a motor so that the number of revolutions can be easily controlled using an inverter. Adopting a direct current motor having a child and controlling the rotational speed of the direct current motor by PWM control or the like, adopting an alternating current motor as the motor and controlling the frequency applied by the inverter or controlling the voltage applied to the motor. Of course, a mode of performing control may be adopted.

  Furthermore, in the embodiment described above, the target rotational speed of the motor is set to a total of five stages corresponding to the magnitude of noise, but the number of stages of the target rotational speed may be arbitrarily set, and further, the noise A mode may be adopted in which the target rotational speed of the motor is set steplessly in correspondence with the size of the motor.

  In addition, when noise is low, a mode is adopted in which the rotational speed is changed linearly by decreasing the rotational speed immediately after the start of operation and increasing the rotational speed as the target rotational speed is approached. A mode in which the period during which the rotational speed is relatively small is made longer without changing the length of the period from the start of operation until the target rotational speed is reached may be adopted.

  In addition, various changes may be made without departing from the spirit of the present invention.

  According to the present invention, in a hydraulic control device including an electric motor and a hydraulic pump in an environment where noise is low, noise leaking to the outside from such a hydraulic control device can be reduced, or in an environment where noise is high. Thus, it is possible to quickly perform the operation using such a hydraulic pressure control device without depending on the degree of sealing of the housing that houses the hydraulic pressure control device or the amount of the soundproofing material inside the housing.

2 ... Actuator 23 ... Hydraulic pump 24 ... Motor 7 ... Control part 7g ... Noise detection element (microphone)

Claims (4)

A hydraulic mechanism including a motor for supplying power to the driven object while operating while maintaining the target rotational speed, a hydraulic mechanism for receiving hydraulic power from the motor and supplying hydraulic pressure, and the hydraulic mechanism One or a plurality of actuators that receive the supply of hydraulic pressure to drive the driven object, a noise detection element that detects the magnitude of noise, and the noise indicated by the signal output from the noise detection element increases as the noise increases. A hydraulic pressure control device comprising: a control unit that performs control to increase a target rotational speed of the motor. The hydraulic control apparatus according to claim 1, wherein the driven object is a cargo bed. The hydraulic control device according to claim 1, wherein the motor is a brushless DC motor. A motor that supplies power to the driving object, a hydraulic mechanism that includes a hydraulic pump that receives the power supplied from the motor and supplies hydraulic pressure, and a driving object that receives the supply of hydraulic pressure from the hydraulic mechanism One or a plurality of actuators for driving the motor, a noise detection element for detecting the magnitude of noise, a control for increasing the target rotational speed of the motor as the noise indicated by the signal output from the noise detection element increases, and A hydraulic pressure control device comprising: a control unit that performs control to decrease a change speed of the rotation speed immediately after the start of operation and increase a change speed of the rotation speed as the target rotation speed is approached.

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