JP2018177006A - Steering control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering control device capable of reducing energy consumption while hardly sacrificing responsiveness of actual assist force when the assist force becomes necessary.SOLUTION: A CPU 82 determines whether a logical sum of a shift position signal SP indicating parking or neutral and a parking brake signal PB being in ON state is true or not, and determines whether a logical product of a vehicle speed SPD being equal to or less than a specified speed and a steering speed based on a steering angle θ being equal to or less than a specified speed is true or not. When the logical product is determined to be true, the CPU 82 makes the flow rate of a working oil discharged from a pump 42 to a hydraulic mechanism 20 via a flow control valve 50 zero.SELECTED DRAWING: Figure 1

Description

  The present invention discharges hydraulic fluid to a hydraulic cylinder including a power cylinder and a switching unit that changes the sign of the assist force output by the power cylinder by switching an oil passage connected to the power cylinder, and the hydraulic mechanism. And a steering control device applied to a power steering device mounted on a vehicle.

  For example, Patent Document 1 below describes a device that variably controls the discharge flow rate of hydraulic fluid from an engine drive type pump driven by an on-vehicle internal combustion engine to a hydraulic mechanism including a power cylinder. Specifically, when the magnitude of the steering angle is small and the change in the steering angle is small, the discharge flow rate is limited to suppress the energy consumption.

JP 10-250613 A

  By the way, when the assist force for steering is shifted from the unnecessary state to the required state, the discharge flow rate is smaller than that for generating the assist force, but is larger than zero when generating the assist force. It is desirable to However, the inventors have found that there is a state where it is particularly desirable to increase the responsiveness of the assist power when the assist power is transferred to a state where the assist power is not required. Therefore, when the above two states are not distinguished, there is a concern that the energy consumption amount may become larger than necessary in a state where it is not desirable to improve the responsiveness of the assist force when shifting to a state requiring assist force. There is.

Hereinafter, the means for solving the above-mentioned subject and its operation effect are described.
1. In the above-described steering control device, there is provided a hydraulic mechanism including a power cylinder, and a switching unit for changing a sign of an assist force output by the power cylinder by switching an oil passage connected to the power cylinder; And a discharge device for discharging the vehicle, wherein the vehicle is provided with at least one of a transmission and a parking brake, and the operating state of the transmission and the parking brake When the start condition including the acquisition process of acquiring at least one operation state of the operation state of and the operation state when the operation state acquired by the acquisition process is in the stop state is satisfied, the condition is not satisfied. And reducing the discharge flow rate of the discharge device to a smaller value than in the case.

  When the operation state of the transmission and the operation state of the parking brake are in the stop state, the responsiveness of the assist force needs to be improved as compared to the case where the operation state is not in the stop state. It is considered that the sex is low. For this reason, in the above-described configuration, the reduction process is performed to reduce the discharge flow rate on the condition that the operation state when the vehicle is in the stopped state. For this reason, the setting of the discharge flow rate by the reduction process is unlikely to be affected by the request for enhancing the response when the assisting force is required, and therefore, the viewpoint of reducing the energy consumption can be mainly considered. Therefore, in the above configuration, it is possible to reduce the energy consumption without sacrificing the responsiveness of the actual assist force when the assist force is required in a situation where high responsiveness is required.

  2. In the steering control device according to the above-mentioned 1, the start condition is a condition indicating that the operation state obtained by the acquisition process is the stop state, and a condition indicating that the vehicle speed is equal to or less than the specified speed. And the condition that the logical product with the condition that the magnitude of the steering speed is equal to or less than the predetermined velocity is true, and the start condition is satisfied, and then the operation state acquired by the acquisition processing becomes the stop state Even when the condition to the effect that the vehicle is operating is satisfied, the condition that the vehicle speed exceeds the specified speed or the condition that the magnitude of the steering speed exceeds the predetermined speed is If it is true, execution of the reduction process is stopped.

  When the vehicle speed exceeds the specified speed, the assist force is generated with high responsiveness by steering being performed, even if the operation state of the transmission or the parking brake is in the stop state, even if the operation state is the stop state. May be required. In addition, when the magnitude of the steering speed exceeds a predetermined speed, an assist force may be required even if the operation state of the transmission or the parking brake is in the stop state. In this respect, in the above configuration, the reduction processing is stopped by increasing the magnitude of the steering speed and the traveling speed, whereby the assist force is generated or the assist force is prepared to be generated with high responsiveness. can do.

  3. In the steering control device according to the above 1 or 2, it is possible to select one of an assist mode for generating the assist force and a standby mode for waiting without generating the assist force based on the operation state of the steering of the vehicle. The determination process to be determined and the reduction process for decreasing the flow rate of the hydraulic fluid discharged by the discharge device to the hydraulic mechanism in the standby mode than in the assist mode are executed, and the reduction process is The flow rate of the hydraulic fluid discharged by the discharge device to the hydraulic mechanism may be smaller than the flow rate by the reduction process.

  In the above configuration, the provision of the standby mode does not necessarily result in the assist mode when the reduction process is not performed. Therefore, when the assist force is transitioned from the state where the assist force is not necessary to the assist mode. It is possible to respond with high responsiveness. For this reason, it is possible to achieve a preferable combination of reducing the energy consumption amount and responding with high responsiveness when the assisting force is required.

4. In the steering control device according to any one of the items 1 to 3, the reduction processing is processing for making the discharge flow rate zero.
5. In the steering control device according to any one of items 1 to 4, the discharge device includes an engine drive type pump driven by a vehicle-mounted internal combustion engine, and the hydraulic mechanism among the hydraulic oil discharged by the pump. And a flow control valve for adjusting an amount returned to the upstream side of the pump without being discharged, wherein the reduction process is discharged from the discharge device to the hydraulic mechanism by operating the flow control valve. It is a process which controls the flow rate of the above-mentioned hydraulic fluid.

  In the above configuration, the pressure loss increases as the amount of hydraulic fluid discharged by the engine drive pump out of the hydraulic mechanism increases, so the power of the pump increases. For this reason, the amount of energy consumption is reduced by operating the flow control valve to increase the amount of hydraulic oil discharged by the engine driven pump and returned to the upstream side of the pump without being discharged to the hydraulic mechanism. be able to.

FIG. 1 is a diagram showing a steering control device and a power steering device according to an embodiment. The flowchart which shows the procedure of the process regarding operation of the flow control valve concerning the embodiment.

Hereinafter, an embodiment according to a steering control device will be described with reference to the drawings.
As shown in FIG. 1, the steering torque input to the steering wheel (steering 10) can be transmitted to the steered wheels 14 via the hydraulic power steering device 12. The power steering device 12 includes a rack and pinion mechanism that converts the rotation of the pinion shaft 22 that rotates in conjunction with the operation of the steering 10 into linear motion of the rack shaft 24 that meshes with the pinion shaft 22. The steered wheels 14 are connected to both ends of the rack shaft 24 via a ball joint or the like. The power steering device 12 assists the operation of the steering 10 by assisting the operation of the rack shaft 24 by the operation of the steering 10.

  The power steering device 12 stores, as a configuration for assisting the operation of the steering 10, the hydraulic mechanism 20, an engine drive type pump 42 (discharge device) driven by rotation of a crankshaft of the internal combustion engine 46, and hydraulic oil. And a flow control valve 50 (discharge device) for adjusting the flow rate of the hydraulic oil discharged by the pump 42 to the hydraulic mechanism 20.

  The hydraulic mechanism 20 includes a power cylinder 30 which incorporates a piston 34 and into which a rack shaft 24 is inserted. A piston 34 is fixed to the rack shaft 24 inside the power cylinder 30. The piston 34 divides the space inside the power cylinder 30 into a first hydraulic chamber 36 and a second hydraulic chamber 38. The difference between the pressure (hydraulic pressure) of the hydraulic fluid in the first hydraulic pressure chamber 36 and the pressure of the hydraulic fluid in the second hydraulic pressure chamber 38 generates a force that displaces the rack shaft 24 in either axial direction. This is the assist force.

  The hydraulic mechanism 20 also includes a steering valve (switching unit 40). The switching unit 40 is a rotary valve provided on the pinion shaft 22 and switching a supply path of hydraulic fluid to the power cylinder 30 and a discharge path of hydraulic fluid from the power cylinder 30 in conjunction with the rotation of the pinion shaft 22.

  Specifically, the switching unit 40 includes a discharge passage 25 into which hydraulic fluid discharged by the pump 42 flows via the flow control valve 50, a first supply / discharge passage 26 connected to the first hydraulic chamber 36, and a second A second supply / discharge passage 27 connected to the hydraulic pressure chamber 38 and a discharge passage 28 connected to the tank 44 are connected. The switching unit 40 communicates the discharge passage 25 with the first supply / discharge passage 26 and communicates the discharge passage 28 with the second supply / discharge passage 27, and communicates the discharge passage 25 with the second supply / discharge passage 27. And the state in which the discharge passage 28 is in communication with the first supply / discharge passage 26 is switched. Here, when the discharge passage 25 is in communication with the first supply / discharge passage 26 and the discharge passage 28 is in communication with the second supply / discharge passage 27, the pressure in the first hydraulic chamber 36 is the second hydraulic chamber 38. As a result, the piston 34 in the power cylinder 30 receives a net force in the first direction D1 of FIG. 1. This force is an assist force that displaces the rack shaft 24 in the first direction D1. On the other hand, when the discharge passage 25 is in communication with the second supply / discharge passage 27 and the discharge passage 28 is in communication with the first supply / discharge passage 26, the pressure in the second hydraulic chamber 38 is the first hydraulic chamber. As a result, the force in the second direction D2 of FIG. 1 is applied to the piston 34 in the power cylinder 30. This force is an assist force that displaces the rack shaft 24 in the second direction D2.

  The flow control valve 50 includes a cylindrical body 52, a cylindrical spool 54, an elastic member (spring 56), a solenoid 58 and a plunger 60. An orifice 62 is provided inside the body 52. A space inside the body 52 is divided into a first chamber 64 and a second chamber 66 with the orifice 62 as a boundary. The first chamber 64 is a discharge destination of the hydraulic fluid from the pump 42 to the flow rate control valve 50. The second chamber 66 is connected to the discharge passage 25.

  The spool 54 is accommodated in the first chamber 64 and is slidable along the axial direction. A spring 56 is accommodated on the side of the first chamber 64 opposite to the orifice 62 with respect to the spool 54. The spring 56 exerts an elastic force on the spool 54 toward the orifice 62. The spring chamber 70 in which the spring 56 is accommodated in the first chamber 64 is connected to the second chamber 66 by bypassing the orifice 62 via the bypass passage 72.

  The second chamber 66 is provided with a solenoid 58 and a plunger 60 inserted into the solenoid 58. A variable orifice is formed by the end face 60 a on the orifice 62 side of the pair of axial end faces of the plunger 60 and the orifice 62. That is, the plunger 60 is axially displaced in accordance with the electromagnetic force corresponding to the current supplied to the solenoid 58, whereby the degree of restriction of the variable orifice is variably set.

  The first chamber 64 is connected to a short loop passage 29 in communication with the suction side of the pump 42. The short loop passage 29 and the first chamber 64 are closed by the spool 54 when the pressure difference between the working oil before and after passing through the variable orifice is equal to or less than a predetermined value. On the other hand, when the pressure difference between the working oil before and after passing through the variable orifice exceeds a predetermined value, in other words, the pressure acting on the end face of the spool 54 on the orifice 62 side is the spring 56 side of the spool 54 The spool 54 is displaced toward the spring 56 when the pressure acting on the end face of the spool is larger than a predetermined pressure. As a result, the short loop passage 29 and the first chamber 64 are in communication.

  The other ECU 74 controls an engine (internal combustion engine 46) and controls various control target devices attached to the internal combustion engine 46 to control control amounts (rotational speed, torque, exhaust component, etc.) of the internal combustion engine 46. The other ECU 74 controls the transmission 76 connected to the crankshaft of the internal combustion engine 46 and controls the transmission gear ratio by operating the transmission 76 based on the shift position signal SP.

  The control device 80 (steering control device) controls the power steering device 12 and controls the assist force as the control amount by operating the flow control valve 50 as the operation target device. When controlling the assist force, the control device 80 inputs the steering angle θ detected by the steering angle sensor 90 and the vehicle speed SPD detected by the vehicle speed sensor 92. Control device 80 can communicate with other ECUs 74 via communication line 94 such as CAN, for example. Thus, control device 80 obtains shift position signal SP via other ECU 74, or obtains parking brake signal PB directly from communication line 94, for example.

  The control device 80 includes a CPU 82, a ROM 84, and a RAM 86. The CPU 82 executes a program stored in the ROM 84 to execute the process of controlling the assist force.

  FIG. 2 shows the procedure of the process related to control of the assist force. The process shown in FIG. 2 is realized by the CPU 82 repeatedly executing the program stored in the ROM 84 at a predetermined cycle. In the following, the step number is represented by a number with "S" added at the beginning.

  In the series of processes shown in FIG. 2, the CPU 82 first calculates the steering speed ω based on the steering angle θ, and acquires the vehicle speed SPD, the shift position signal SP, and the parking brake signal PB (S10). Next, the CPU 82 determines whether it is in the eco mode (S12). The eco mode is a mode in which the discharge amount of hydraulic fluid from the flow control valve 50 to the hydraulic mechanism 20 is made zero. When the CPU 82 determines that the mode is not the eco mode (S12: NO), whether the logical product of the following condition (i), condition (i) and condition (iii) is true continues for a prescribed time or not Is determined (S14). This condition is a condition for setting the eco mode.

  Condition (A): A condition that the logical sum of the shift position signal SP indicating the parking P or the neutral N and the parking brake signal PB being on is true. This condition is a condition indicating that the shift operation state when the driver is in the stop state or the operation state of the parking brake.

Condition (b): A condition that the vehicle speed SPD is less than or equal to the specified speed Sth. This condition is a condition that the driver is considered to have an intention to stop the vehicle.
Condition (c): A condition that the magnitude of the steering speed ω is equal to or less than a predetermined speed. This condition is a condition that the driver does not intend to operate the steering 10.

  When it is determined that the logical product is true (S14: YES), the CPU 82 sets the eco mode (S16). Then, the CPU 82 sets the command value of the discharge flow rate of the hydraulic fluid from the flow control valve 50 to the hydraulic mechanism 20 to zero (S18), and the discharge flow rate of the hydraulic fluid from the flow control valve 50 to the hydraulic mechanism 20 becomes zero. , Operate the flow control valve 50 (S34).

  On the other hand, when the CPU 82 determines that the eco mode is set (S12: YES), the CPU 82 determines whether the logical sum of the condition (e) and the condition (f) is true (S20). ). This condition is a condition for canceling the eco mode.

  Condition (d): The condition that the shift position signal SP does not indicate the parking P and the neutral N, and the parking brake signal PB is in the OFF state. This condition is a condition that the shift operation or the operation of the parking brake is not the operation state when the driver is in the stop state.

Condition (O): A condition that the vehicle speed SPD is higher than the specified speed Sth. This condition is a condition that it is considered that the driver does not intend to stop the vehicle.
Condition (f): A condition that the magnitude of the steering speed ω exceeds a predetermined speed. This condition is a condition that the driver has an intention to operate the steering 10.

  When it is determined that the logical sum is false (S20: NO), the CPU 82 proceeds to the process of S18. On the other hand, when it is determined that the logical sum is true (S20: YES), the CPU 82 cancels the eco mode (S22). When the process of S22 is completed or when the determination of step S14 is negative, the CPU 82 executes a determination process of determining the drive mode of the flow control valve 50 (S24). Specifically, the CPU 82 first determines whether an assist is necessary. The CPU 82 determines that the vehicle speed SPD is equal to or less than the vehicle speed threshold and the magnitude of the steering speed .omega. Is equal to or greater than the steering speed threshold, and the vehicle speed SPD is higher than the vehicle speed threshold and the magnitude of the steering angle .theta. On the condition that the logical sum of the large value and the logical value is true, it is determined that the assist is necessary. On the other hand, under the condition that the CPU 82 determines that the logical sum is false, the CPU 82 determines that the assist is not necessary. Next, when it is determined that the assist is not necessary, the CPU 82 slightly supplies the hydraulic oil from the flow control valve 50 to the hydraulic mechanism 20 so that the assist force can be quickly generated when the assist becomes necessary. It is determined that the standby mode is continued. On the other hand, when determining that the assist is necessary, the CPU 82 determines that the assist mode is set. Incidentally, the vehicle speed threshold may be about the above-mentioned specified speed Sth, and in the present embodiment, a value lower than the specified speed Sth is exemplified. The steering speed threshold may be about the predetermined speed ωth, and in the present embodiment, a value lower than the predetermined speed ωth is exemplified.

  When it is determined that the assist mode is set (S26: YES), the CPU 82 selects an assist mode map (S28). The assist mode map is stored in advance in the ROM 84. The map is a set of data of each discrete value of the input variable and the value of the output variable. Specifically, in the assist mode map, when the vehicle speed SPD as an input variable is low, the command value of the flow rate as an output variable is set to a larger value than when it is high, and the magnitude of the steering speed ω as an input variable is When the value is larger, the command value of the flow rate as the output variable is set to a larger value than when it is smaller.

  On the other hand, when it is determined that the CPU 82 is in the standby mode (S26: NO), the CPU 82 selects the standby mode map (S30). In the standby mode map according to the present embodiment, the input variable is the vehicle speed SPD and the output variable is the command value of the flow rate, but the flow rate is a constant value regardless of the vehicle speed SPD.

  When the processing of S28 and S30 is completed, the CPU 82 performs map operation on the command value of the flow rate of hydraulic fluid from the flow control valve 50 to the hydraulic mechanism 20 (S32). In the map operation, for example, when the value of the input variable matches any of the values of the input variable of map data, the value of the output variable of the corresponding map data is taken as the operation result, and when they do not match, a plurality of items included in the map data The value obtained by interpolation of the values of the output variables of may be used as the processing result.

Then, the CPU 82 operates the flow control valve 50 by operating the energizing current of the solenoid 58 so as to obtain the command value of the flow obtained by the map calculation (S34).
Here, the operation of this embodiment will be described.

  When the eco mode is not set, the CPU 82 sets the assist mode or the standby mode depending on whether the assist force is required, and the discharge flow rate of hydraulic fluid from the flow control valve 50 to the hydraulic mechanism 20 is larger than zero. Control to value. On the other hand, in the eco mode, the CPU 82 controls the discharge flow rate of hydraulic oil from the flow control valve 50 to the hydraulic mechanism 20 to zero. Here, among the hydraulic fluid discharged by the pump 42, the hydraulic fluid flowing out to the hydraulic mechanism 20 via the flow control valve 50 has a pressure loss larger than that of the hydraulic fluid flowing through the short loop passage 29. Therefore, if the discharge flow rate of the hydraulic oil by the pump 42 is the same, the smaller the flow rate of the hydraulic oil flowing out to the hydraulic mechanism 20 through the flow control valve 50, the more necessary for the internal combustion engine 46 to drive the pump 42 Power is reduced. Therefore, by setting the discharge flow rate from the flow control valve 50 to the hydraulic mechanism 20 to zero, the amount of fuel consumed by the internal combustion engine 46 can be reduced compared to the case where it is not set to zero. Further, as a result, since the pressure loss applied to the hydraulic oil is smaller compared to the case where the discharge flow rate from the flow control valve 50 to the hydraulic mechanism 20 is made larger than zero, the temperature of the hydraulic oil is suppressed from rising. You can also

According to the embodiment described above, the following effects can be obtained.
(1) Even when the condition (i) is satisfied, the eco mode is canceled when the condition (e) is satisfied. As a result, in the case where steering is performed while the vehicle is traveling, in view of the necessity to generate the assist force with high responsiveness, the assist mode is increased by canceling the eco mode. It can be prepared when it is necessary to generate with responsiveness.

(2) When the above condition (f) is satisfied, the eco mode is canceled. Thereby, the assist force can be generated when steering is performed.
(3) In the eco mode, the discharge flow rate from the flow control valve 50 to the hydraulic mechanism 20 is smaller than in the standby mode. Thereby, when the possibility that the assist force is immediately required is low by continuing the state where the logical product of the above conditions (i), (i) and (ii) becomes true, the assist force is low. The energy consumption can be reduced compared to the standby mode, which copes with the occurrence of requests that are generated quickly. Therefore, the energy consumption can be reduced while responding to the case where the responsiveness is required when the assisting power is required.

<Correspondence relationship>
Correspondence between the matters in the above-mentioned embodiment and the matters described in the above-mentioned "means for solving the problem" is as follows. Below, correspondence is shown for every number of the solution means described in the column of "Means for solving the problem". [1] The discharge device corresponds to the pump 42 and the flow control valve 50, and the steering control device corresponds to the control device 80. The acquisition process corresponds to the process of S10, and the reduction process corresponds to the process of S18. [2] The "eco mode determination condition" corresponds to the condition used in the process of S14 and S20. [3] The “steering operation state” is quantified by the steering speed ω and the steering angle θ, and the weight reduction processing corresponds to the processing of S30.

<Other Embodiments>
In addition, you may change at least one of each matter of the said embodiment as follows.
・ "About acquisition processing"
In the above embodiment, both the shift position signal SP and the parking brake signal PB are acquired, but only one of them may be acquired.

・ "About reduction processing"
In the above embodiment, the discharge flow rate is set to zero in the eco mode, but the present invention is not limited to this. For example, it may be a fixed value smaller than the flow rate in the standby mode but larger than zero.

・ "About the execution condition of reduction processing"
The determination condition (execution condition of reduction processing) of the eco mode is not limited to the condition that the logical product of the above conditions (A) to (C) is true. For example, instead of the above condition (A), a condition that the logical product of the shift position signal SP indicating the parking P or the neutral N and the parking brake signal PB being on may be true is also possible. . In addition, for example, as described in the column "About Acquisition Processing", in the case where the shift position signal SP is not acquired while acquiring the parking brake signal PB, the parking brake signal PB is substituted for the condition (A). It may be on condition that it is on. Further, for example, as described in the column of “Regarding acquisition processing”, in the case where the parking brake signal PB is not acquired while acquiring the shift position signal SP, the shift position signal SP is It may be conditioned to indicate parking P or neutral N. In addition, as the determination condition of the eco mode, the logical product of the above conditions (A) to (C) and the condition that the magnitude (absolute value) of the steering angle θ is less than or equal to a prescribed value Good. Further, in the process of FIG. 2, the determination process is performed prior to the determination of the eco mode, and it is determined that the logical product of the fact that the standby mode is determined and the above condition (a) is true. It may be a judgment condition of the eco mode. In this case, when the determination condition of the eco mode is satisfied, the standby mode is switched to the eco mode.

・ "About discharge device"
The discharge device is not limited to the one provided with the pump 42 and the flow control valve 50. For example, it may be an electric pump driven by the power of the on-board battery to make the discharge amount variable. In this case, since the amount of work performed by the electric pump is increased when the discharge amount of the electric pump is large compared to when the discharge amount of the electric pump is small, reducing the discharge amount of the electric pump as much as possible is In order to reduce the energy consumption, it is effective to provide the eco mode in the manner of the above embodiment.

・ "About steering control device"
The CPU 82 and the ROM 84 are not limited to the ones that execute software processing. For example, a dedicated hardware circuit (for example, an ASIC or the like) may be provided which performs hardware processing on at least a part of the software processed in the above embodiment. That is, the steering control device may have any one of the following configurations (a) to (c). (A) A processing device that executes all of the above processes in accordance with a program, and a program storage device such as a ROM that stores the program. (B) A processing device and a program storage device that execute part of the above processing according to a program, and a dedicated hardware circuit that performs the remaining processing. (C) A dedicated hardware circuit is provided to execute all of the above processes. Here, the software processing circuit provided with the processing device and the program storage device, and a dedicated hardware circuit may be plural. That is, the above process may be performed by a processing circuit including at least one of one or more software processing circuits and one or more dedicated hardware circuits.

・ "Others"
It is not essential to have a standby mode. Even if you do not have the standby mode, if you transition from a state where assist power is not actually necessary to a necessary state in a state that is not the eco mode, cancel the eco mode from the eco mode to assist The responsiveness of the assist force can be improved more than when generating a force.

DESCRIPTION OF SYMBOLS 10 ... Steering, 12 ... Power steering apparatus, 14 ... Steering wheel, 20 ... Hydraulic mechanism, 22 ... Pinion shaft, 24 ... Rack axis, 25 ... Discharge passage, 26 ... 1st supply / discharge passage, 27 ... 2nd supply / discharge passage , 28: discharge passage, 29: short loop passage, 30: power cylinder, 34: piston, 36: first hydraulic chamber, 38: second hydraulic chamber, 40: switching unit, 42: pump, 44: tank, 46: Internal combustion engine, 50: flow control valve, 52: body, 54: spool, 56: spring, 58: solenoid, 60: plunger, 60a: end face, 62: orifice, 64: first chamber, 66: second chamber, 70 ... spring room, 72 ... bypass passage, 74 ... other ECU, 76 ... transmission, 80 ... control device, 82 ... CPU, 84 ... ROM, 86 ... RAM, 90 ... steering angle sensor, 92 ... vehicle speed sensor, 94 ... communication .

Claims (5)

A hydraulic mechanism comprising: a power cylinder; and a switching unit for switching a sign of an assist force output from the power cylinder by switching an oil passage connected to the power cylinder; a discharge device for discharging hydraulic fluid to the hydraulic mechanism , And applied to a power steering apparatus mounted on a vehicle,
The vehicle is provided with at least one of a transmission and a parking brake.
Acquisition processing for acquiring at least one of an operation state of the transmission and an operation state of the parking brake;
When the start condition including the condition to the effect that the operation state acquired by the acquisition process is the stop state is satisfied, the reduction process of setting the discharge flow rate of the discharge device to a smaller value than when not satisfied And a steering control device to perform. The start condition is a condition indicating that the operation state obtained by the acquisition processing is the stop state, a condition indicating that the vehicle speed is equal to or less than the specified speed, and a steering speed having a predetermined speed Including the condition that the logical product with the condition that is the following is true,
The condition that the vehicle speed exceeds the specified speed even when the condition to the effect that the operation state obtained by the acquisition processing is the stop state is satisfied after the start condition is satisfied. The steering control device according to claim 1, wherein the execution of the reduction processing is stopped when the logical sum of the condition that the magnitude of the steering speed exceeds a predetermined speed is true. A determination process of determining which of an assist mode for generating the assist force and a standby mode for waiting without generating the assist force based on an operation state of steering of the vehicle;
A reduction process for reducing the flow rate of the hydraulic fluid discharged by the discharge device to the hydraulic mechanism in the standby mode than in the assist mode;
The steering control device according to claim 1 or 2, wherein the reduction processing is processing to make the flow rate of the hydraulic fluid discharged by the discharge device to the hydraulic mechanism smaller than the flow rate by the reduction processing.   The steering control device according to any one of claims 1 to 3, wherein the reduction process is a process of setting the discharge flow rate to zero. The discharge device adjusts an amount of an engine drive type pump driven by a vehicle-mounted internal combustion engine and an amount of the hydraulic fluid discharged by the pump, which is returned to the upstream side of the pump without being discharged to the hydraulic mechanism. And a flow control valve,
The steering according to any one of claims 1 to 4, wherein the reduction process is a process of controlling the flow rate of the hydraulic oil discharged from the discharge device to the hydraulic mechanism by operating the flow control valve. Control device.