JP2521245Y2 - Motor control device for vehicles with power steering - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a prime mover control device for a vehicle equipped with a power steering, which is preferably used for a hydraulically driven vehicle such as a wheel hydraulic excavator.

[Conventional technology]

In general, a hydraulically driven vehicle such as a wheel hydraulic excavator is equipped with a hydraulically driven power steering so that an operating force applied to a steering wheel during steering operation can be reduced.

Therefore, FIGS. 7 to 10 show a wheel hydraulic excavator as an example of a prime mover control device for a vehicle equipped with a power steering according to the prior art.

In the figure, 1 is a lower traveling body, 2 is an upper revolving body mounted on the lower traveling body 1 so as to be rotatable, and the upper revolving body 2 has a cab 2A, a machine room 2B and a counterweight 2C.
Etc. are provided. Reference numeral 3 denotes a working device provided at a front portion of the upper revolving unit 2, and the working device 3 includes a boom 3A and an arm 3
B and a bucket 3C and the like, and the bucket 3C performs excavation work of earth and sand.

Here, the lower traveling body 1 is provided with a chassis 4 as a frame and front wheels 5, 5 as wheels which are provided on the front part of the chassis 4 and are steered at both axial ends thereof with universal joints 6, 6. A front axle housing 7 (see FIG. 8) attached via a rear axle and a rear axle housing (not shown) provided on the rear portion of the chassis 4 and attached with rear wheels 8 (only one is shown) on both axial ends. ) And is composed of. Reference numeral 9 denotes a speed reducer provided on the lower side of the central portion of the chassis 4, the input side of the speed reducer 9 is connected to a traveling hydraulic motor (not shown), and the output side is connected via propeller shafts 10 and 11. It is connected to the front wheel 5 and each rear wheel 8. The front wheels 5 and the rear wheels 8 are driven by a traveling hydraulic motor via a speed reducer 9 and propeller shafts 10 and 11 to drive the vehicle on the road.

Reference numeral 12 denotes a steering mechanism provided on the front wheel 5 side of the undercarriage 1, and 13 denotes a steering cylinder arranged between the steering mechanism 12 and the chassis 4.
13 is a rod 13 by pressure oil from a hydraulic pump 15 described later.
A is expanded and contracted to operate the steering mechanism 12. Then, the steering mechanism 12 includes a rod 13
The steering angle of the front wheels 5, 5 is changed according to the amount of expansion and contraction of A,
Is designed to be steered.

Reference numeral 14 denotes a prime mover provided in the machine room 2B of the upper swing body 2. The prime mover 14 is composed of a diesel engine or the like, and the rotation speed of the output shaft 14A is controlled by a governor 23 described later. . Reference numeral 15 denotes a hydraulic pump that is provided in the machine room 2B and is driven by a prime mover 14. The hydraulic pump 15 discharges the hydraulic oil in the tank 16 as high pressure oil toward the steering cylinder 13 and the like. There is. 17A and 17B are a pair of main pipes connecting the steering cylinder 13 to the hydraulic pump 15 and the tank 16, and 18 is a steering valve as a control valve provided in the middle of the main pipes 17A and 17B. Is operated by a steering handle 19 provided in the driver's cab 2A of the upper swing body 2, and controls the flow rate and direction of the pressure oil supplied to the steering cylinder 13 in accordance with the operating angle of the handle 19. There is.

Here, the steering valve 18 is composed of a hydraulic servo valve incorporating a known orbit roll, etc.
Regardless of the pressure of the pressure oil discharged from 15, the rod of the steering cylinder 13 is in an amount corresponding to the operating angle of the handle 19.
13A is configured to expand and contract, and a large operating force needs to be applied to the handle 19 when the pressure of the pressure oil is low, but the operating force of the handle 19 can be effectively reduced when the pressure of the pressure oil is high. Has become.

20 is a steering cylinder 13 and a steering valve 18
And a switching valve provided in the middle of the main pipelines 17A, 17B, between which the switching valve 20 is switched between the switching position (a) and the switching position (b) by the driver, and the upper turning is performed. Body 2
The steering direction can be appropriately reversed depending on whether the vehicle is facing forward or backward with respect to the undercarriage 1. Reference numeral 21 denotes a center joint as a rotary joint provided between the steering cylinder 13 and the switching valve 20 and provided in the middle of the main pipelines 17A, 17B. The center joint 21 is the lower traveling body 1 and the upper revolving body 2. It is arranged between and.
22A and 22B are hydraulic pump 15, tank 16 and steering valve
18 shows another main pipeline branched from the main pipelines 17A, 17B, and the main pipelines 22A, 22B are connected to, for example, a traveling hydraulic motor, and the pressure oil from the hydraulic pump 15 is supplied to the hydraulic motor, etc. It is designed to be supplied to and discharged from.

Reference numeral 23 denotes a governor that is attached to the prime mover 14 and controls the rotational speed of the prime mover 14. The governor 23 has a governor lever 23A, and the number of revolutions of the prime mover 14 (engine speed is determined according to the rotation angle of the governor lever 23A). N) is increased or decreased. Reference numeral 24 denotes an electric motor that constitutes a rotation speed control mechanism that controls the rotation speed of the prime mover 14 together with the governor 23.
To rotate the governor lever 23A via the link 25,
The rotation speed of the prime mover 14 is controlled based on a target rotation speed N _ro described later.

Reference numeral 26 is connected to the drive lever 24A of the electric motor 24 via a link 27, and the rotation angle of the drive lever 24A is changed to the governor lever 2A.
A rotation angle sensor for detecting the rotation angle of 3A is shown, and the rotation angle sensor 26 detects the rotation speed of the prime mover 14 based on the rotation angle of the governor lever 23A, and the rotation speed detection value N _rp will be described later. By outputting to the controller 29, the servo control of the rotation speed is performed as described later.

28 indicates a command device as command means for commanding the number of revolutions of the prime mover 14, and the command device 28 is constituted by a fuel lever or a traveling pedal (neither shown) provided in the cab 2A, etc. The command signal N _X of the rotation speed according to the operation amount of is output to the controller. Further, reference numeral 29 denotes a controller composed of a microcomputer or the like, the input side of the controller 29 is connected to the command device 28 and the rotation angle sensor 26 and the like, and the output side thereof is connected to the electric motor 24 and the like. The controller 29 stores the programs and the like shown in FIGS. 9 and 10 in its memory circuit and performs the rotational speed control processing of the prime mover 14 including the servo control processing. Further, the controller 29 stores in the storage area of the storage circuit a map similar to the target rotation speed map shown in FIG.
The target rotation speed N _ro is set based on the command signal N _X from 28.

A motor control device for a wheel hydraulic excavator according to the prior art has the above-described configuration.
The rotation speed control processing of the prime mover 14 by the controller 29 will be described with reference to FIG.

First, when the processing operation is started, the command signal N _X is read from the command device 28 in step 1, and the process proceeds to step 2 where the target rotation speed map is based on this command signal N _X (see FIG. 3)
The target rotation speed N _ro is read from, and the servo control process shown in FIG. 10 is performed in step 3.

That is, in the servo control process, in step 11, the target rotation speed
N _ro is read out, the rotational speed detection value N _rp is read in step 12, the process _proceeds to step 13, and the rotational speed difference n is calculated as n = N _rp −N _ro (1), and in step 14, the rotational speed difference n Absolute value of | n | is greater than or equal to a predetermined hysteresis value K,
When the determination is “NO”, the rotation speed detection value N _rp substantially corresponds to the target rotation speed N _ro , so in step 15, the electric motor 24 is stopped and the drive lever 24A is held at the rotation angle. To output the control signal.

Further, when it is determined to be “YES” in step 14, it is determined whether or not the rotation speed difference n is a positive value in step 16, and when it is determined to be “NO”, the rotation speed detection value N _rp is the target value. Since the value is smaller than the rotation speed N _ro , in step 17, the normal rotation control signal is output to the electric motor 24 so that the rotation speed detection value N _rp as the actual rotation speed approaches the target rotation speed N _ro. To control. When it is determined to be "YES" in step 16, a reverse rotation control signal is output to rotate the electric motor 24 in the reverse direction to control the rotation speed of the prime mover 14 based on the target rotation speed N _ro .

Accordingly, the rotation speed of the prime mover 14 is the target rotation speed N _ro ,
That is, controlled based on the command signal N _X from the command device 28,
When no operation is performed for a command device 28 (e.g., accelerator pedal, etc.), the rotational speed of the prime mover 14 will be lowered until the idle speed N _o (see FIG. 3).

[Problems to be Solved by the Invention] By the way, in the above-mentioned conventional technique, the prime mover 14 drives the hydraulic pump 15, and the hydraulic pump 15 discharges pressure oil toward the steering cylinder 13 and the traveling hydraulic pump. Therefore, the discharge amount of this pressure oil becomes minimum when the prime mover 14 is idling. The idle speed is normally set to be as low as possible from the viewpoint of noise and fuel consumption of the prime mover 14, so that the amount of pressure oil discharged from the hydraulic pump 15 during idle rotation of the prime mover 14 is It is drastically reduced, and it is not possible to supply sufficient pressure oil to the steering cylinder 13 during steering operation.
There is a problem that it becomes very heavy.

In particular, in the case where the command device 28 is configured by the traveling pedal, when the steering operation is performed by the handle 19 while releasing the traveling pedal during traveling, the hydraulic pressure is reduced according to the rotation speed of the prime mover 14 decreasing to the idle rotation speed. Since the discharge amount of the pump 15 is reduced, there is a problem that the steering angle at the time of steering is gradually reduced and the handle 19 becomes heavy, so that safety during traveling cannot be ensured.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can automatically increase the rotational speed of the prime mover when steering operation is performed even when the prime mover is idling, thereby improving safety during steering operation. The present invention provides a prime mover control device for a vehicle equipped with such a power steering system.

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention provides a steering mechanism provided in a vehicle for steering wheels, a prime mover provided in the vehicle, and a hydraulic pump driven by the prime mover to discharge pressure oil, A steering cylinder that is connected to the hydraulic pump and the tank via a pair of main pipelines and operates the steering mechanism by supplying pressure oil from the hydraulic pump, and between the steering cylinder and the hydraulic pump and the tank. A control valve that is located in the middle of each of the main pipelines and that controls the flow rate and direction of the pressure oil supplied to the steering cylinder according to the operating angle of the steering wheel; and a command that commands the rotational speed of the prime mover. The present invention is applied to a prime mover control device for a vehicle equipped with a power steering.

The feature of the configuration adopted by the device according to claim 1 is that detection means for detecting whether or not the steering mechanism is in an operating state, and when the operating state of the steering mechanism is detected by the detecting means, The rotation speed commanding means compares the rotation speed commanded by the commanding means with a predetermined steering target rotation speed and controls the rotation speed of the prime mover to a larger value.

Further, in the invention according to claim 2, the detecting means detects the driving pressure of the steering cylinder.

Further, according to the third aspect of the invention, the target steering speed is variably set so as to increase or decrease according to the drive pressure of the steering cylinder detected by the detecting means.

Further, in the invention according to claim 4, the vehicle is a hydraulically driven vehicle that is driven and driven by the pressure oil from the hydraulic pump.

[Action]

With the above configuration, in the device according to claim 1, when the rotation speed by the command means is commanded as a rotation speed higher than the steering target rotation speed at the time of steering operation, the engine up to the rotation speed corresponding to the command rotation speed. The number of rotations of can be increased. Then, even if the rotation speed by the command means is lowered to, for example, the idle rotation speed during the steering operation, the rotation speed of the prime mover can be automatically increased to a steering target rotation speed higher than the idle rotation speed, and the minimum steering operation is required. It is possible to reliably supply the required amount of pressure oil from the hydraulic pump to the steering cylinder.

According to the second aspect of the invention, it is possible to reliably detect whether or not the steering mechanism is in the operating state by detecting the driving pressure of the steering cylinder.

Further, according to the third aspect of the invention, the steering target drive speed is increased or decreased in accordance with the drive pressure of the steering cylinder, so that the drive pressure of the steering cylinder is relative when the road surface on which the vehicle is traveling is flat. The target steering speed can be lowered accordingly, and the speed of the prime mover can be reduced to a relatively low speed. Then, when the road surface condition becomes a bad road, the driving pressure of the steering cylinder becomes relatively large, and accordingly, the steering target rotation speed can be increased, and the rotation speed of the prime mover is relatively high. It can be increased up to the number of rotations.

Furthermore, in the invention according to claim 4, by configuring the vehicle as a hydraulically driven vehicle, pressure oil from a hydraulic pump is supplied to and discharged from, for example, a traveling hydraulic motor provided in the vehicle to drive the vehicle on the road. Can be run.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 6. In the embodiment, the same components as those of the prior art shown in FIG. 7 and FIG.
The description will be omitted.

1 to 3 show a first embodiment of the present invention.

In the figure, 31 is located between the steering valve 18 and the switching valve 20, and serves as a high-pressure selection valve provided between the main pipelines 17A ₁ and 17B ₁ which are cylinder drive pipelines from the steering valve 18. A shuttle valve is shown, said shuttle valve 31 being the main line 17
The pressure oil on the high pressure side, that is, the drive pressure of the steering cylinder 13 is selected from A ₁ and 17B ₁ , and this drive pressure is applied to a pressure switch 32 described later. Reference numeral 32 denotes a pressure switch as a detection means for detecting the operating state of the steering mechanism 12, and the pressure switch 32 is turned on and off by the driving pressure of the steering cylinder 13 derived from the shuttle valve 31.
Then, it is detected whether or not it is in the steering state. That is, when the steering valve 18 is operated by the handle 19, the pressure oil from the hydraulic pump 15 is supplied to the main pipelines 17A ₁ , 17B.
_It is supplied to either _one of ₁ and the driving pressure becomes high,
As a result, the pressure switch 32 is turned on and the operating state of the steering mechanism 12 is detected.

Further, 33 is a controller that constitutes the rotation speed control means of the prime mover 14 together with the governor 23 and the like.
Although it has a configuration similar to that of the controller 29 described in the prior art, a pressure switch 32 is connected to the input side thereof in addition to the rotation angle sensor 26 and the command device 28. The controller 33 stores the program and the like shown in FIG. 2 in its memory circuit, and performs the rotational speed control processing of the prime mover 14. In the storage circuit of the controller 33, the target rotation speed map shown in FIG. 3 and the set value of the steering target rotation speed N _ks (N _ks > N _o ) as a predetermined set rotation speed are stored in the storage area 33A. Is stored.

The prime mover control device according to the present embodiment has the above-mentioned configuration. Next, the rotational speed control processing of the prime mover 14 by the controller 33 will be described with reference to FIGS. 2 and 3.

First, when the processing operation starts, in step 21, the signal from the pressure switch 32 and the command signal from the command device 28 are sent.
After reading N _X , the process proceeds to step 22 and the target rotational speed N _rx is read from the map shown in FIG. 3 based on the command signal N _X. Then, the process proceeds to step 23, from the signal of the pressure switch 32, it is determined whether or not the steering operation is being performed, and if "YES" is determined, the process _proceeds to step 24 to read the steering target rotation speed N _ks , and at step 25 It is determined whether the steering target rotation speed N _ks is larger than the target rotation speed N _rx .

Then, when it is determined “YES” in step 25,
For example, the target speed N _rx is the idle speed N shown in FIG.
lowered to about _o, because smaller than the steering target rotational speed N _ks, a steering target rotational speed N _ks set as the target rotational speed N _ro proceeds to step 26, based on the target rotational speed N _ro In step 27, servo control processing as shown in FIG. 10 is performed. As a result, the rotational speed of the prime mover 14 is increased to a rotational speed higher than the idle rotational speed N _o, and the hydraulic fluid of the flow rate required for steering operation can be discharged from the hydraulic pump 15 toward the steering cylinder 13.

Further, when it is determined to be "NO" in step 23, the steering mechanism 13 is not in the operating state, so the _{routine proceeds} to step 28, where the target rotation speed N _rx by the command device 28 is changed to the target rotation speed N _ro.
Then, in step 27, the servo control device is operated as in the conventional technique. Further, when it is determined to be "NO" in step 25, the target rotation speed N _rx by the command device 28 is equal to or higher than the steering target rotation speed N _ks . Therefore, also in this case, the process _proceeds to step 28 and the target rotation speed N _{rx. Is} set as the target rotation speed N _ro , and servo control processing is performed in step 27.

Thus, according to the present embodiment, even when the rotational speed of the prime mover 14 is reduced to about the idle rotational speed N _o, when performing steering operation, the rotational speed of the prime mover 14 is automatically _adjusted to the steering target rotational speed N _ks. Since it can be increased, the hydraulic pump 15 can supply pressure oil to the steering cylinder 13 at a flow rate necessary for steering operation, and it is possible to solve problems such as a smaller steering steering angle and a heavier steering wheel 19. Can improve the safety of. In addition, when the steering operation is not performed, it is possible to reduce the number of revolutions during idling as much as possible, noise of the prime mover 14 can be reduced, and fuel efficiency performance can be improved.

Next, FIGS. 4 to 6 show a second embodiment of the present invention. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. However, the feature of the present embodiment is that the steering drive pressure P _s of the steering cylinder 13 is detected by the pressure sensor 41 as the detection means, and based on this steering drive pressure P _s , the steering target rotation speed as the set rotation speed. N _rs is variably set as shown in the target rotation speed map shown in FIG.

Here, although the controller 42 has substantially the same structure as the controller 33 described in the first embodiment, the pressure sensor 41 is connected to the input side thereof, and the rotation of the prime mover 14 is changed as shown in the program shown in FIG. A number control process is performed. Further, the storage circuit of the controller 42 stores the target rotational speed maps and the like shown in FIGS. 3 and 5 in its storage area 42A.

Then, when the processing operation is started, the controller 42 reads the steering driving pressure P _s from the pressure sensor 31 and the command signal N _X from the command device 28 in step 31, when the processing operation starts, as in the program shown in FIG. At 32, the target rotation speed N _rx is read from the map shown in FIG. 3 based on the command signal N _X , and at step 33, the steering target rotation speed N _rs is read from the map shown in FIG. 5 based on the drive pressure P _s . Next, the routine proceeds to step 34, where it is determined whether or not the steering target rotation speed N _rs is larger than the target rotation speed N _rx, and when it is judged "YES", the _routine proceeds to step 35 where this target rotation speed N _rs is reached.
_Is set as the target rotation speed N _ro , and servo control processing is performed in step 36. When it is determined to be “NO” in step 34, the target rotation speed N _rx by the command signal N _X is set as the target rotation speed N _ro , and the servo control process is performed in step 36.

Thus, the present embodiment configured as described above can obtain substantially the same operation and effect as the first embodiment. However, particularly in the present embodiment, the target steering speed N _rs is based on the driving pressure P _s . Since the map is increased / decreased as shown in FIG. 5, for example, when steering on a flat road where the driving pressure P _s is small, the rotation speed of the prime mover 14 can be made as small as possible, and the driving pressure P _s becomes large. The number of revolutions can be increased during steering on the road, the number of revolutions of the prime mover 14 can be selected during steering according to the road surface condition, and labor can be saved.

In each of the above embodiments, the target steering speed N
_ks when (N _rs) is smaller than the target rotational speed N _rx is the prime mover 1 on the basis even when the steering operation to the target speed N _rx
Although it was described as controlling the number of revolutions of 4, instead of this, the number of revolutions of the prime mover 14 is always set during steering operation.
It may be controlled so that the number of revolutions required for steering operation (discharging amount of the hydraulic pump 15) becomes higher than the target number of revolutions N _rx . It is possible to effectively eliminate a problem such as a temporary decrease in driving force.

Further, in each of the above embodiments, the wheel type hydraulic excavator has been described as an example, but the present invention is not limited to this, and can be applied to various hydraulically driven vehicles such as a wheel type hydraulic crane, for example. The vehicle can be driven to run by the pressure oil, and the operating force applied to the steering wheel 19 or the like during steering operation can be significantly reduced by the hydraulic pressure.

[Effect of device]

As described in detail above, according to the present invention, as described in claim 1, when the detection means detects the operating state of the steering mechanism, the rotation speed commanded by the rotation speed control means is predetermined. Compared with the steering target rotation speed, the rotation speed of the prime mover is controlled to a larger value.Therefore, when operating the steering wheel, set the rotation speed of the prime mover to a steering target rotation speed higher than the idle rotation speed or higher. The number of rotations can be automatically increased, and the minimum amount of pressure oil required for steering operation can be reliably supplied from the hydraulic pump to the steering cylinder, and problems such as a smaller steering angle and a heavier steering wheel are solved. It is possible to improve the safety during driving. In addition, when the steering operation is not performed, the engine speed can be reduced to the idle speed to set the idle speed as low as possible, and the noise of the engine can be reliably reduced to ensure fuel efficiency. Can be improved.

Further, according to the second aspect of the present invention, by detecting the driving pressure of the steering cylinder, it can be surely detected whether or not the steering mechanism is in the operating state, and the case where the steering operation is performed and the case where the steering operation is not performed. Can be accurately determined.

Further, according to the third aspect of the present invention, the steering target rotation speed is increased or decreased according to the driving pressure of the steering cylinder, so that when the vehicle travels on a flat road surface, the driving pressure of the steering cylinder is relatively high. If it becomes smaller, the target steering speed can be reduced accordingly, and the speed of the prime mover can be reduced to a relatively low speed. Further, when the road surface condition becomes a bad road, the driving pressure of the steering cylinder becomes relatively large. Therefore, by increasing the steering target rotation speed accordingly, the rotation speed of the prime mover becomes relatively high. The number can be increased to a certain number, and it is possible to reliably prevent the steering angle from becoming small and the steering wheel from becoming heavy while traveling on a bad road.

Furthermore, in the invention according to claim 4, by configuring the vehicle as a hydraulically driven vehicle, pressure oil from a hydraulic pump is supplied to and discharged from, for example, a traveling hydraulic motor provided in the vehicle to drive the vehicle on the road. The hydraulic pump can be driven, and the hydraulic pump can be used both as a hydraulic pressure source for the steering cylinder and a hydraulic pressure source for the traveling hydraulic motor.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention, FIG. 1 is a hydraulic circuit diagram for steering, FIG. 2 is a flow chart showing a rotational speed control process, and FIG. 3 is a memory area of a controller. Explanatory drawing of the stored map, FIGS. 4 to 6 show the second embodiment, FIG. 4 is a hydraulic circuit diagram for steering, and FIG. 5 is an explanatory view of the map stored in the memory area of the controller. FIG. 6 is a flow chart similar to FIG. 3, FIGS. 7 to 10 show prior art, FIG. 7 is an overall view of a wheel type hydraulic excavator, FIG. 8 is a hydraulic circuit diagram for steering, and FIG. FIG. 10 is a flow chart showing rotation control processing, and FIG. 10 is a flow chart showing servo control processing. 1 ... Lower traveling body, 2 ... Upper swing body, 4 ... Chassis, 5 ... Front wheel, 12 ... Steering mechanism, 13 ... Steering cylinder, 14 ... Motor, 15 ... Hydraulic pump,
16 ... Tank, 17A, 17B ... Main pipeline, 18 ... Steering valve (control valve), 19 ... Handle, 23 ... Governor,
24 ... Electric motor, 26 ... Rotation angle sensor, 28 ... Command device, 32 ... Pressure switch (detection means), 33, 42 ... Controller, 41 ... Pressure sensor (detection means).

Claims (4)

(57) [Scope of utility model registration request] 1. A steering mechanism provided in a vehicle for steering wheels, a prime mover provided in the vehicle, and a hydraulic pump driven by the prime mover to discharge pressure oil.
A steering cylinder that is connected to the hydraulic pump and the tank via a pair of main pipelines and operates the steering mechanism by supplying pressure oil from the hydraulic pump, and between the steering cylinder and the hydraulic pump and the tank. A control valve that is located in the middle of each of the main pipelines and that controls the flow rate and direction of the pressure oil supplied to the steering cylinder according to the operating angle of the steering wheel; and a command that commands the rotational speed of the prime mover. In a prime mover control device for a vehicle equipped with power steering, the detection means detects whether or not the steering mechanism is in an operating state, and the command means when the operating state of the steering mechanism is detected by the detecting means. Compare the rotation speed commanded by and the predetermined steering target rotation speed, and And a rotation speed control means for controlling the rotation speed of the prime mover at a value of 0. 2. The prime mover control device for a vehicle equipped with a power steering according to claim 1, wherein said detection means detects a driving pressure of a steering cylinder. 3. The prime mover control device for a vehicle equipped with a power steering according to claim 2, wherein the steering target rotation speed is variably set so as to increase or decrease according to the drive pressure of the steering cylinder detected by the detecting means. . 4. The vehicle is a hydraulically driven vehicle that is driven and driven by pressure oil from a hydraulic pump.
A prime mover control device for a vehicle equipped with the power steering according to.