JP2017001461A - Oil pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil pressure control device that can maintain steering function even when malfunction occurs to a power steering mechanism.SOLUTION: The oil pressure control device supplies operating oil to a steering cylinder and performs operation of a steering. The oil pressure control device comprises: an operation-side pump that feeds operating oil by steering the steering wheel and a first supply passage through which the operating oil fed by the operation-side pump is supplied to the steering cylinder. The oil pressure control device comprises a power-side pump which feeds the operating oil by power of a motor according to steering quantities of the steering wheel and a second supply passage through which the fed operating oil is supplied to the steering cylinder. Further the oil pressure control device comprises a switching portion that switches the supply passage for the operating oil to the steering cylinder, to either one of the first supply passage and the second supply passage, and a controller which controls switching of the supply passage by the switching portion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydraulic control device.

  In industrial vehicles and the like, power steering is mainly used as a steering mechanism. By using power steering, it is possible to reduce the burden on the operator who operates the steering wheel of the industrial vehicle.

  Patent Document 1 discloses a hydraulic control device that supplies hydraulic oil from one hydraulic pump in a divided manner to a hydraulic power steering device and a cargo receiving control device.

JP 2008-68648 A

  As one of the power steering mechanisms, for example, there is a steer-by-wire system. In the steer-by-wire system, the steering angle of the steering wheel is read by a rotary sensor, and a motor connected to the hydraulic pump is rotated according to the read steering angle. And a power steering mechanism is implement | achieved by sending out hydraulic fluid to a steering cylinder.

  However, for example, when a problem occurs in the power steering mechanism, such as when power supply is stopped, the hydraulic pump cannot be operated, and thus steering cannot be performed. Therefore, when a problem occurs in the power steering mechanism, emergency braking is unavoidable due to its safety, but such emergency braking gives an operator an unpleasant feeling and anxiety. Therefore, it is desirable to be able to maintain the steering function even when a problem occurs in the power steering mechanism.

  The present invention has been made paying attention to such problems, and an object of the present invention is to provide a hydraulic control device capable of maintaining a steering function even when a malfunction occurs in a power steering mechanism. .

  In order to achieve the object, the hydraulic control device of the present invention is a hydraulic control device that supplies hydraulic oil to a steering cylinder to operate a vehicle steering. The hydraulic control device includes an operation side pump that sends hydraulic oil by steering the steering wheel, and a first supply passage that supplies the hydraulic oil sent by the operation side pump to the steering cylinder. In addition, the hydraulic control device includes a power-side pump that sends hydraulic oil by power from a motor according to a steering amount of the steering wheel, and a second supply passage that supplies the hydraulic oil sent by the power-side pump to the steering cylinder. Prepare. The hydraulic control device further includes a switching unit that switches the supply passage of hydraulic oil to the steering cylinder to one of the first supply passage and the second supply passage, and a controller that controls switching of the supply passage in the switching unit. .

  According to the hydraulic control device of the present invention, in a normal operation, the hydraulic oil supply passage to the steering cylinder is made the second supply passage, so that the hydraulic oil is sent to the steering cylinder by the power of the motor. Then, the steering operation can be performed using a so-called power steering mechanism. On the other hand, if a problem occurs in the power steering mechanism, the hydraulic oil supplied to the steering cylinder is supplied to the steering cylinder by setting the hydraulic oil supply passage to the steering cylinder as the first supply passage. And send. Thus, the steering operation can be performed directly by steering the steering wheel. By doing so, it is possible to provide a hydraulic control device that can maintain the steering function even when a problem occurs in the power steering mechanism.

FIG. 1 is a hydraulic circuit diagram of a hydraulic control apparatus according to the present embodiment. FIG. 2 is a flowchart for explaining the operation of the hydraulic control apparatus according to this embodiment. FIG. 3 is a hydraulic circuit diagram of a hydraulic control device according to a comparative example.

  FIG. 1 is a hydraulic circuit diagram of a hydraulic control apparatus according to the present embodiment. The hydraulic control device 1 in this embodiment includes a manual operation circuit 10 and a motor drive circuit 20. The hydraulic control device 1 includes a controller 30 and a battery 40. The hydraulic control device 1 includes a steering cylinder 21 that is a hydraulic control target, and a steering wheel 11 for operating the steering. The entire hydraulic control device 1 constitutes a power steering mechanism.

  The manual operation circuit 10 sends hydraulic oil to the steering cylinder 21 by steering the steering wheel 11. And steering operation of a vehicle is performed manually. The vehicle is a forklift, for example.

  The motor drive circuit 20 rotates the pump motor 26 according to the steering amount of the steering wheel, and sends hydraulic oil to the steering cylinder 21 by the power of the pump motor 26. The motor drive circuit 20 performs the steering operation of the vehicle using the power of the pump motor 26.

  The controller 30 performs control to switch the hydraulic circuit connected to the steering cylinder 21 from one of the manual operation circuit 10 and the motor drive circuit 20 to the other. The controller 30 may control not only the hydraulic control device 1 but also other parts of the vehicle on which the hydraulic control device 1 is mounted.

  The battery 40 is connected to the controller 30 and supplies power to the controller 30. In the hydraulic control apparatus 1 according to the present embodiment, power is supplied to each part in the hydraulic control apparatus 1 via the controller 30.

  Hereinafter, the configuration of the manual operation circuit 10 will be described.

  The manual operation circuit 10 includes a hydraulic pump 12 (corresponding to an operation side pump), a proportional solenoid valve 13, check valves 14a and 14b, hydraulic sensors 15a and 15b, and a reservoir tank T1 for storing hydraulic oil.

  The hydraulic pump 12 is mechanically connected to the steering wheel 11. The hydraulic pump 12 is rotated by steering the steering wheel 11, and sends hydraulic oil corresponding to the steering angle of the steering wheel 11 to the passage 51a or the passage 51b. If the rotation speed of the steering wheel 11 is increased, the rotation speed of the hydraulic pump 12 is also increased. As the hydraulic pump 12, for example, an orbit roll pump or the like can be employed.

  The proportional solenoid valve 13 is electrically connected to the controller 30. The proportional solenoid valve 13 communicates the passage 53a and the passage 53b when the valve position is the B position. Further, the proportional solenoid valve 13 causes the passage 53a and the passage 53b to communicate with each other through a minimum throttle valve when the valve position is the A position.

  When the proportional solenoid valve 13 is in the B position, the opening degree of the valve is controlled by current control from the controller 30. And the controller 30 controls the opening degree of the valve, whereby the flow rate can be controlled in the range of 0% to 100%. In this way, by limiting the flow rate within the range of 0% to 100%, the proportional solenoid valve 13 exhibits the effect of a minimum throttle valve with respect to the hydraulic oil. The minimum throttle valve for the hydraulic oil generates a steering reaction force on the steering wheel 11.

  One end of the check valve 14a is connected to the passage 51a and the passage 53a. On the other hand, the other end of the check valve 14a is connected to the passage 52a. The passage 52a is inserted into the reservoir tank T1, and when the hydraulic pressure on the passage 51a side is low, the check valve 14a is opened, and the hydraulic oil in the reservoir tank T1 is supplied to the passage 51a side. Then, the shortage of hydraulic oil on the passage 51a side is compensated.

  Similarly, one end of the check valve 14b is connected to the passage 51b and the passage 53b. On the other hand, the other end of the check valve 14b is connected to the passage 52b. The passage 52b is inserted into the reservoir tank T1, and when the hydraulic pressure on the passage 51b side is low, the check valve 14b is opened and the hydraulic oil in the reservoir tank T1 is supplied to the passage 51b side. Then, the shortage of hydraulic oil on the passage 51b side is compensated.

  The oil pressure sensor 15a detects the oil pressure in the passage 53a. The hydraulic sensor 15 a is connected to the controller 30. Thereby, the controller 30 can read the hydraulic pressure value of the passage 53a. Similarly, the hydraulic pressure sensor 15b detects the hydraulic pressure in the passage 53b. The hydraulic sensor 15 b is connected to the controller 30. Thereby, the controller 30 can read the hydraulic pressure value of the passage 53b. The controller 30 feedback-controls the proportional solenoid valve 13 according to the oil pressure acquired by the oil pressure sensors 15a and 15b. Then, the reaction force generated on the steering wheel 11 is stabilized.

  The rotary sensor 19 is connected to the controller 30 and sends information on the steering angle of the steering wheel 11 to the controller 30.

  Next, the configuration of the motor drive circuit 20 will be described.

  The motor drive circuit 20 includes solenoid valves 22 and 23, relief valves 24a and 24b, a shuttle valve 25, a pump motor 26, a hydraulic pump 27 (power side pump), check valves 28a and 28b, and reservoir tanks T2 and T3.

  The solenoid valve 22 is electrically connected to the controller 30. When the solenoid valve 22 is not energized, the valve position is the A position. The solenoid valve 22 connects the passage 53a and the passage 56a when the valve position is the A position. Further, the solenoid valve 22 causes the passage 54a and the passage 56a to communicate with each other when the valve position is the B position.

  The solenoid valve 23 is electrically connected to the controller 30. When the solenoid valve 23 is not energized, the valve position is the A position. The solenoid valve 23 communicates the passage 53b and the passage 56b when the valve position is the A position. Further, the solenoid valve 23 communicates the passage 54b and the passage 56b when the valve position is the B position.

  The relief valve 24a is connected to the passage 54a. When the hydraulic pressure in the passage 54a is high, the hydraulic oil is released to the reservoir tank T3 via the passage 57 so that the hydraulic pressure in the passage 54a does not increase too much. The relief valve 24b is connected to the passage 54b. When the hydraulic pressure in the passage 54b is high, the hydraulic oil is released to the reservoir tank T3 via the passage 57 so that the hydraulic pressure in the passage 54b does not increase too much.

  The shuttle valve 25 is connected to the passage 54a and the passage 54b. When the hydraulic pressure in one of the passages 54a and 54b increases, the valve in the other passage is opened. By doing in this way, even when the low-pressure side hydraulic oil is insufficient, the hydraulic oil in the reservoir tank T3 can be supplied. For example, when the hydraulic pressure on the passage 54a side is low and the hydraulic oil is insufficient, the hydraulic oil can be supplied to the passage 54a. Further, when the hydraulic pressure on the passage 54b side is low and the hydraulic oil is insufficient, the hydraulic oil can be supplied to the passage 54b.

  The pump motor 26 is electrically connected to the controller 30. The pump motor 26 is mechanically connected to the hydraulic pump 27. The rotation speed of the pump motor 26 is controlled by the controller 30. The controller 30 controls the rotational speed of the pump motor 26 according to the steering angle of the steering wheel acquired by the rotary sensor 19. The hydraulic pump 27 sends hydraulic oil from the passage 54a to the passage 54b or sends hydraulic oil from the passage 54b to the passage 54a according to the rotation direction and the rotation speed rotated by the pump motor 26.

  A check valve 28a is connected to the passage 54a. A passage 55a is connected to the check valve 28a. The lower end of the passage 55a is inserted into the reservoir tank T2. A check valve 28b is connected to the passage 54b. A passage 55b is connected to the check valve 28b. The lower end of the passage 55b is inserted into the reservoir tank T2. When the hydraulic oil in the passage 54b is sent to the passage 54a side by the hydraulic pump 27 and the hydraulic oil on the passage 54b side becomes insufficient, the hydraulic oil in the reservoir tank T2 is sucked up through the passage 55b and the passage 58. Further, when the hydraulic oil in the passage 54a is sent to the passage 54b side by the hydraulic pump 27, the hydraulic oil in the reservoir tank T2 is sucked up through the passage 55a and the passage 58 when the hydraulic oil on the passage 54a side becomes insufficient. It is done.

  In this embodiment, when the forklift is turned on and control is started by the controller 30, the valve positions of the proportional solenoid valve 13, the solenoid valve 22, and the solenoid valve 23 are all controlled to the B position. When there is no malfunction in the power steering mechanism, the valve positions of the proportional solenoid valve 13, the solenoid valve 22, and the solenoid valve 23 are all maintained at the B position. When the valve position of the proportional solenoid valve 13 is set to the B position, the opening degree is controlled by the controller 30 as described above.

  On the other hand, when the control is not performed by the controller 30 such as when the power of the forklift is not turned on, the valve positions of the proportional solenoid valve 13, the solenoid valve 22, and the solenoid valve 23 are the A position. Even when the power steering mechanism has a problem, the valve positions of the proportional solenoid valve 13, the solenoid valve 22, and the solenoid valve 23 are set to the A position under the control of the controller 30.

  FIG. 2 is a flowchart for explaining the hydraulic pressure control process in the present embodiment. Hereinafter, the hydraulic control processing in the present embodiment will be described with reference to the flowchart and FIG. 1 described above.

  When the power of the forklift on which the hydraulic control device 1 is mounted is turned on, the controller 30 of the hydraulic control device 1 starts the hydraulic control process. When the hydraulic control process is started, the controller 30 determines whether or not a problem has occurred in the power steering mechanism (S102). The failure of the power steering mechanism means that, for example, when it becomes difficult to supply power from the battery 40, when the hydraulic pressure value is not properly output from the hydraulic sensors 15a and 15b, This is the case when a disconnection occurs between other devices.

  If no problem has occurred in the power steering mechanism, the controller 30 switches the hydraulic circuit connected to the steering cylinder 21 to the motor drive circuit 20 (S104). Specifically, the controller 30 switches the valve position of the proportional solenoid valve 13 to the B position, switches the valve position of the solenoid valve 22 to the B position, and switches the valve position of the solenoid valve 23 to the B position. When the hydraulic circuit connected to the steering cylinder 21 is the motor drive circuit 20 before switching, the hydraulic circuit connected to the steering cylinder 21 is maintained as the motor drive circuit 20.

  The solenoid valve 22 blocks communication between the passage 56a and the passage 53a (first supply passage) and connects the passage 56a and passage 54a (second supply passage). Further, the solenoid valve 23 blocks communication between the passage 56b and the passage 53b (first supply passage), and connects the passage 56b and the passage 54b (second supply passage).

  At this time, let us consider a case where the steering wheel 11 is steered clockwise and the steering is about to be steered to the right. Here, it is assumed that the hydraulic control device 1 is mounted on a forklift for rear wheel steering, and when the steering is steered to the right, the hydraulic pressure in the passage 56b needs to be increased. On the other hand, when the steering is steered to the left, it is necessary to increase the hydraulic pressure in the passage 56a.

  The controller 30 monitors the steering angle of the steering wheel 11 from the rotary sensor 19. When the steering wheel 11 is steered clockwise, the controller 30 controls the rotation of the pump motor 26 so as to send hydraulic oil to the passage 54b. When the hydraulic pressure in the passage 54b is increased, the hydraulic pressure in the passage 56b is also increased, so that the steering cylinder 21 operates the steering so as to turn the vehicle clockwise. The controller 30 increases the rotational speed of the pump motor 26 as the steering angle of the steering wheel 11 increases.

  Since the check valve 28b is provided, the hydraulic oil is not returned to the reservoir tank T2 through the passage 55b. The relief valve 24b allows hydraulic oil to escape to the reservoir tank T3 to such an extent that the hydraulic pressure in the passage 54b does not become too high.

  The shuttle valve 25 opens the valve of the passage 54a opposite to the passage 54b where the hydraulic pressure is increased. Thereby, when the hydraulic oil in the passage 54a is insufficient, the hydraulic oil can be supplied to the passage 54a from the reservoir tank T3.

  On the other hand, when the steering wheel 11 is steered counterclockwise, the controller 30 controls the rotation of the pump motor 26 so as to send hydraulic oil to the passage 54a. When the hydraulic pressure in the passage 54a is increased, the hydraulic pressure in the passage 56a is also increased, so that the steering cylinder 21 operates the steering so as to turn the vehicle counterclockwise.

  Since the check valve 28a is provided, the hydraulic oil is not returned to the reservoir tank T2 through the passage 55a. The relief valve 24a allows hydraulic oil to escape to the reservoir tank T3 to such an extent that the hydraulic pressure in the passage 54a does not become too high. The shuttle valve 25 opens the valve of the passage 54b opposite to the passage 54a where the hydraulic pressure is increased. Thereby, when the hydraulic oil in the passage 54b is insufficient, the hydraulic oil can be supplied to the passage 54b from the reservoir tank T3.

  As described above, when the steering wheel 11 is steered clockwise, the hydraulic pump 12 supplies the hydraulic oil in the passage 51a and the passage 53a to the passage 53b. When the steering wheel 11 is steered counterclockwise, the hydraulic pump 12 supplies the hydraulic oil in the passage 51b and the passage 53b to the passage 53a. At this time, the proportional solenoid valve 13 limits the throttle amount by the current control of the controller 30. The proportional solenoid valve 13 can control the hydraulic oil flow rate between the passage 53a and the passage 53b to be low, and can generate an appropriate steering reaction force on the steering wheel 11.

  As described above, when there is no malfunction in the power steering mechanism, the controller 30 switches the hydraulic circuit connected to the steering cylinder 21 to the motor drive circuit 20. Therefore, since the steering is operated using the motor drive circuit 20 in normal times, the operator can easily operate the steering.

  On the other hand, if a problem has occurred in the power steering mechanism in step S102, the controller 30 switches the hydraulic circuit connected to the steering cylinder 21 to the manual operation circuit 10 (S106). Specifically, the controller 30 switches the valve position of the proportional solenoid valve 13 to the A position, switches the valve position of the solenoid valve 22 to the A position, and switches the valve position of the solenoid valve 23 to the A position.

  The solenoid valve 22 blocks communication between the passage 56a and the passage 54a (second supply passage), and connects the passage 56a and passage 53a (first supply passage). Further, the solenoid valve 23 blocks communication between the passage 56b and the passage 54b (second supply passage), and connects the passage 56b and the passage 53b (first supply passage).

  At this time, let us consider a case where the steering wheel 11 is steered clockwise and the steering is about to be steered to the right. Here, when the steering is steered to the right, it is necessary to increase the hydraulic pressure in the passage 56b. On the other hand, when the steering is steered to the left, it is necessary to increase the hydraulic pressure in the passage 56a.

  When the steering wheel is steered clockwise, the hydraulic pump 12 sends hydraulic oil from the passage 51a to the passage 53b through the passage 51b. Since the check valve 14b is provided, the hydraulic oil is not returned to the reservoir tank T1 through 52b.

  When hydraulic oil is sent to the passage 53b, the hydraulic pressure on the passage 53b side increases. Since the valve position of the solenoid valve 23 is the A position and the passage 53b and the passage 56a communicate with each other, the hydraulic pressure in the passage 53b is transmitted to the passage 56b. As a result, the hydraulic pressure in the passage 56b is increased, and the steering cylinder 21 operates the steering so as to turn the vehicle clockwise.

  In this way, when a malfunction occurs in the power steering mechanism for some reason, the hydraulic oil can be directly sent to the steering cylinder 21 by the operation of the steering wheel 11 to control the steering.

  At this time, since the valve position of the proportional solenoid valve 13 is the A position, a minimum throttle valve exists between the passage 51a and the passage 51b. The minimum throttle valve of the proportional solenoid valve 13 reduces the flow rate of the hydraulic oil between the passage 53a and the passage 53b and generates a steering reaction force on the steering wheel 11.

  When there is a problem with the power steering mechanism, it may be difficult to supply power from the battery 40. However, since the minimum throttle valve exists between the passage 51a and the passage 51b when the valve position of the proportional solenoid valve 13 is in the A position as described above, the throttle amount is controlled by current control from the controller 30. Even in the case where it is not possible, a steering reaction force can be applied to the steering wheel 11.

  On the other hand, when the steering wheel 11 is steered counterclockwise, the operation is reverse to that when the steering wheel 11 is steered clockwise. For example, when the steering wheel 11 is steered counterclockwise, hydraulic oil is sent from the passage 51b to the passage 53a through the passage 51a. As a result, the hydraulic pressure in the passage 56a increases, and the steering cylinder 21 operates the steering so as to turn the vehicle counterclockwise.

  Thus, when the process of step S104 or step S106 is completed, the controller 30 ends the hydraulic pressure control process. In the present embodiment, the processes in steps S102 to S106 shown in FIG. 2 are repeatedly executed at predetermined time intervals.

  Next, the hydraulic control device in the comparative example will be described, and the advantages of the hydraulic control device in the present embodiment will be described in comparison with the hydraulic control device in the comparative example.

  FIG. 3 is a hydraulic circuit diagram of a hydraulic control device according to a comparative example. The hydraulic control device 101 in the comparative example includes a steering angle detection unit 110, a motor drive circuit 120, a controller 130, and a battery 140. The hydraulic control apparatus 101 in the comparative example includes a steering cylinder 21 that is a hydraulic control target and a steering wheel 11 for operating the steering. In this comparative example, the same elements as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The steering angle detection unit 110 includes a rotary sensor 119. The rotary sensor 119 is mechanically connected to the steering wheel 11 and detects the steering angle of the steering wheel 11. The rotary sensor 119 is electrically connected to the controller 130. Then, the rotary sensor 119 sends the steering angle of the steering wheel 11 to the controller 130.

  The motor drive circuit 120 hydraulically controls the steering cylinder 21 under the control of the controller 130. Then, the wheels attached to the steering cylinder 21 are steered. The motor drive circuit 120 in the hydraulic control device 101 of the comparative example operates in substantially the same manner as the motor drive circuit 20 in the hydraulic control device 1 of the above-described embodiment.

  The controller 130 reads the steering angle of the steering handle 11 via the rotary sensor 119. Then, the controller 130 rotates the pump motor 126 according to the read steering angle. Further, an electromagnetic brake coil 118 that electrically generates a steering reaction force is connected to the steering handle 11. The electromagnetic brake coil 118 is connected to the controller 130. The controller 130 supplies a current corresponding to the steering angle of the steering handle 11 to the electromagnetic brake coil 118. The electromagnetic brake coil 118 generates a steering reaction force corresponding to the current value on the steering handle.

  Here, for example, let us consider a case where power is no longer supplied from the battery 40 in the hydraulic control apparatus 101 of the comparative example. When power is not supplied from the battery 40, the controller 130 cannot acquire the steering angle of the rotary sensor 119. Moreover, since the pump motor 26 cannot be rotated, hydraulic fluid cannot be sent to the passage 154a or the passage 154b. Therefore, when power is not supplied from the battery 40, no further steering operation can be performed.

  Furthermore, in the hydraulic control apparatus 101 of the comparative example, since the steering reaction force is generated in the steering wheel 11 by supplying the current to the electromagnetic brake coil 118, the steering reaction force is also generated when the electric power cannot be supplied. I can't do that. And there exists a problem that the steering wheel 11 will idle freely.

  On the other hand, according to the present embodiment, ease of operation is ensured by using the motor drive circuit 20 during normal operation, while the manual operation circuit 10 is always connected to the steering cylinder when a malfunction of the power steering mechanism occurs. 21 will be connected. Thereby, even if a problem occurs in the power steering mechanism, the steering operation can be performed using the hydraulic pressure supplied from the manual operation circuit 10. In addition, safety can be ensured even when a power steering mechanism malfunction occurs.

  Further, according to the present embodiment, the manual operation circuit 10 is connected to the steering cylinder 21 when the forklift is powered off. At this time, since the steering reaction force due to the hydraulic pressure in the manual operation circuit 10 acts on the steering wheel 11, it is possible to prevent the steering wheel 11 from rotating while the vehicle is stopped.

  Further, according to the present embodiment, the manual operation circuit 10 is always connected to the steering cylinder 21 by the spring force of the solenoid valves 22 and 23 even when no control is performed by the controller 30. . For this reason, a so-called fail-safe mechanism works, and safety can be further improved.

  The steering circuit 20 in the present embodiment is desirably provided on the rear wheel side of the forklift. That is, the hydraulic pump 27 and the pump motor 26 are provided closer to the steering cylinder 21 than the hydraulic pump 12. This is because the forklift has steering on the rear wheel side, so that the above-described motor drive circuit 20 can reduce hydraulic pressure loss if the forklift is provided on the rear wheel side.

  In the present embodiment, the hydraulic pressure generated by the pump 12 is used as the steering reaction force, but the steering reaction force may be generated by an electromagnetic brake coil as in the comparative example. Further, the steering reaction force may be generated using both the generated hydraulic pressure and current control.

  Further, a tire angle sensor may be provided in the vicinity of the steering cylinder 21, and the rotational speed of the pump motor 26 may be corrected according to the acquired tire angle.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

DESCRIPTION OF SYMBOLS 1 Hydraulic control apparatus 10 Manual operation circuit 11 Steering wheel 12 Hydraulic pump (operation side pump)
13 Proportional solenoid valve (switching part)
14a check valve 14b check valve 15a oil pressure sensor 15b oil pressure sensor 19 rotary sensor 20 motor drive circuit 21 steering cylinder 22 solenoid valve 23 solenoid valve 24a relief valve 24b relief valve 25 shuttle valve 26 pump motor 27 hydraulic pump (power side pump)
28a Check valve 28b Check valve 30 Controller 40 Battery 53a, 53b passage (first supply passage)
54a, 54b passage (second supply passage)
T1 reservoir tank T2 reservoir tank T3 reservoir tank

Claims (6)

A hydraulic control device that supplies hydraulic oil to a steering cylinder to operate a steering of a vehicle,
An operation side pump for sending hydraulic oil by steering the steering wheel;
A first supply passage for supplying hydraulic oil delivered by the operation side pump to the steering cylinder;
A power-side pump that sends hydraulic oil by power from a motor in accordance with the steering amount of the steering wheel;
A second supply passage for supplying hydraulic oil delivered by the power pump to the steering cylinder;
A switching unit that switches a supply passage of hydraulic oil to the steering cylinder to one of the first supply passage and the second supply passage;
A controller for controlling switching of the supply passage in the switching unit;
A hydraulic control device comprising: The hydraulic control device according to claim 1,
The switching unit is a solenoid valve connected to the first supply passage and the second supply passage;
The controller is a hydraulic control device that performs switching between the first supply passage and the second supply passage through the solenoid valve. The hydraulic control device according to claim 2,
The solenoid valve has a throttle portion that limits the flow rate of the hydraulic oil,
A hydraulic control device for restricting a flow rate of hydraulic oil sent out by the operation side pump when a hydraulic oil supply passage to the steering cylinder is switched to the first supply passage. The hydraulic control device according to any one of claims 1 to 3,
The hydraulic control device for switching the hydraulic oil supply path to the steering cylinder to the first supply path when the power steering mechanism including the second supply path is defective. The hydraulic control device according to any one of claims 1 to 4,
A hydraulic control device in which the power side pump is provided closer to the steering cylinder than the operation side pump. The hydraulic control device according to any one of claims 1 to 5,
A hydraulic control device in which the steering cylinder is provided on a rear wheel side of the vehicle.

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