JPS59140167A - Power steering used for vehicle - Google Patents

Abstract

PURPOSE:To provide a constant steering force irrespective of weather by providing a reaction regulating valve in a path affording communication between a pair of reaction chambers of a control valve to controllably open and close said regulating valve according to the signals from a wiper switch and a vehicle speed sensor. CONSTITUTION:A pair of reaction chambers 43, 44 are provided at both sides of a spool 31 of a control valve 13 and communicate with each other through a reaction communicating path 15 which is provided with a reaction adjusting valve 16. The throttle of this valve 16 is controlled by a control unit 60 on the basis of signals from a wiper switch 61 and a vehicle speed sensor 62. That is, the adjusting valve 16 is adjusted such that in fine weather or low speed, the throttle of the reaction adjusting valve 16 is small and in rainy weather or high speed the throttle of the reaction adjusting valve 16 is large.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to improvements in power steering used in vehicles.

In general, power steering has been designed to generate a response, or in other words, a reaction force, in order to make the driver feel the weight of steering, that is, the steering resistance from the road surface.

However, if the magnitude of the reaction force is set small, an appropriate steering force can be obtained when stopped or at low speeds, but at high speeds,
The response was too light and the steering tended to become unstable.

Furthermore, if the magnitude of the reaction force is set large, an appropriate steering force can be obtained at high speeds, but when the vehicle is stopped or at low speeds, the steering force becomes too heavy.

In order to avoid such inconveniences, conventionally, internal combustion engine rotation speed-sensitive flow rate restrictor valve types, vehicle speed-sensitive oil pressure reaction force increasing types, etc., have been developed to increase the reaction force depending on the driving conditions.
Steering and war steering methods have been proposed that change the steering force, but the range of reaction force variation is usually narrow, making it difficult to obtain the most appropriate reaction force depending on the vehicle's driving conditions. In addition, the means for changing the reaction force in this way tend to be complicated and the production cost to be high.

Furthermore, when a vehicle is running, cornering force varies depending on the resistance of the road surface. In other words, cornering force is significantly lower on a wet road than on a dry road. However, with conventional power steering, the reaction force is determined depending on the vehicle speed or engine speed, so
It is difficult to change the reaction force according to the cornering force, and therefore, the steering force tends to be different when driving on a sunny day and when driving on a rainy day.

The purpose of this invention is to always obtain an appropriate reaction force depending on the driving condition of the vehicle, reduce fatigue caused by steering operation,
In particular, under conditions where the cornering force is extremely different, such as when driving on a sunny day and when driving on a rainy day, the steering force can be kept virtually constant, enabling safe driving, and the structure is relatively simple. Our goal is to provide power steering for use in vehicles.

With these issues in mind, the power steering used in the vehicle of this invention consists of an oil pump, a flow fist control shaft, a pair of control pulp spools on both sides of the control pulp spool, a flow pump, a flow control valve, and a pair of control valves on both sides of the control pulp spool. −・For those that are connected to a cylinder, the rear auxiliary control communication passage, the sonocontrol
A pair of reaxicon chambers of the pulp are provided to communicate with each other, and a reaction force regulating valve is disposed in the reaxicon communication passage, and a control unit electrically connects the Wyno 9 switch and the vehicle speed sensor. and is configured to control the output current that opens and closes the reaction force regulating valve according to signals from them.

Hereinafter, preferred specific examples of the power steering system used in the vehicle of the present invention will be described with reference to the drawings.

The figure shows specific example 10 of power steering used in a vehicle of the present invention applied to a cab-over type truck.
is shown in outline.

The power steering 10 is an oil impeller 11.
and a pair of reactor chambers 43 and 44 on both sides of the control pulp spool 31. A communication passage 15 is provided so as to communicate the pair of reaction chambers 43 and 44 of the control pulp 13 with each other, and a reaction force adjustment valve 16 is disposed in the reaction communication passage 15.・
A unit 60 is connected to a wiper switch 61 and a vehicle speed sensor 62, and controls the output current for opening and closing the reaction force regulating valve 16 according to signals from them, and controls the output current in the pair of reactor chambers 43 and 44. It is configured so that the reaction force can be changed by adjusting the pressure.

The oil pump 11 is driven by an internal combustion engine (not shown) mounted on the cab/autocouple truck, and sucks up the pressure oil in the Oil Lisano 956, and is approximately proportional to the rotational speed of the internal combustion engine. It is configured such that a discharge amount of pressurized oil can be obtained.

The oil pump 11 is configured similarly to an oil pump used in existing power steering systems, so a description of its configuration will be omitted.

Flow control pulp 12 ij:, So(D Pump port 17 connected to the discharge side of the oil pump 11, Control pulp port 18 connected to the supply port 22 side of the control pulp 13 described later
, and a casing including a suction port 19 connected to the suction side of the oil bomb 7'll, and an oil return control sole (not shown) disposed in the casing so as to be able to reciprocate and slide. etc. 9, adjust the flow rate of the pressure oil sent to the pump port 17 side, send a predetermined flow rate to the control pulp port 18 side, and also send the surplus flow from the suction port 19. It is configured to be returned to the suction side of the oil pump ll, that is, to the oil reservoir 56 side.

SonoFlow Control Pulp 12 is a flow control pulp used in existing power steering.
Since it has the same structure as pulp, detailed explanation of its structure will be omitted.

Control Φpal 7' 13 i! :, spool chamber 2L-t(7) flow control pulp 1
2 control pulp port 18 side
- a supply port 22 connecting to the stool chamber 21, a discharge port 1-23 connecting the stool chamber 21 to its oil reservoir 56 side, and a nozzle cylinder i-124, 25, 26; Control ◎ Valve E/ring 20, its supply port 22, its discharge port 23, and power, 7 cylinder, I?
- 424, 25° 26 and a control and pulp spool 31 which are reciprocally slidably disposed within the spool chamber 21 and the spool spool.
In the chamber 21, the control pulp sufu 0 of
- a pair of reactor chambers 43, 44 formed on both sides of the wheel 31.

Of course, ring grooves 29.30 are respectively formed in the spool chamber 21 in communication with the supply and discharge ports 22.23.

14f-c, control of Italy Pulp C Suzor 31
is placed in the neutral position, its ring groove 29.3
The control pulp located outside of 0
Lands 32.35 are formed around both ends of the spool 31, and between the lands 32.35 there are lands 33.34 facing the ring grooves 29.30.
are formed respectively.

Of course, between those lands 32, 33, 34, 35,
Spool grooves 36, 37, 38 are formed, respectively, which can be connected to the power cylinder ports 1-24, 25° 26.

Sarani, the control pulp spool 31 is located inside both ends of the sonocontrol pulp spool 31.
A bore 39.40 is formed extending along the axial direction and open at both ends, and the bore 39.40
is connected to the spool groove 36. through the communication hole 41.42.
37 respectively.

Therefore, the grooves 36 and 37 are connected to the communication hole 4.
1, 42 and via bores 39, 40 to reactor chambers 43, 44, respectively.

'17''r, Sonocontrol O Pulp C Sulfur 3
1 is a lever that slides back and forth in response to steering operation;
One end of a shaft 59 is fixed at approximately the center of the sonocontrol pulp stool 31, and the other end of the shaft 59 passes through the control pulp casing 20 and is attached to a steering shaft (not shown). ) side is connected.

The cylinder 14 is formed integrally with the casing 20 of the control pulp 13 and is connected to the cylinder ports 24, 25, 26. A power cylinder casing with a cylinder bore 48 and a pair of cylinder chambers 49.50 connected correspondingly to its power/cylinder holes 1, 24, 25 and 26, respectively.
The cylinder bore 48 is formed within the cylinder bore 48.
It consists of a power piston 51 disposed so as to be able to reciprocate and slide within the bore 48, and to further explain the output section conceptually, one end is connected to the power piston 51, and the other end is connected to the power cylinder. - A push rod 52 that penetrates the casing and protrudes outward, and a push rod 52 that is attached to the power cylinder casing approximately coaxially with the push rod 52 at a position opposite to the push rod 52. It is composed of a fixed rod 53.

Of course, the power cylinder ports 24,25 of the sonocontrol pulp 13 are connected to its cylinder chamber 50 via communication passages 45,46, and the power cylinder ports 26 are connected to its cylinder chambers 50 via communication passages 47. In the cylinder chamber 49,
each connected.

The other end of the bushing rod 52 of the power cylinder 14 configured in this way is connected to the front frame side of the cab-over type truck, and a rod located on the opposite side of the bushing rod 520. 53 is attached to a drag link (not shown) that drives a steering arm (not shown). ' = 1, Integral Renault? In the power steering gear, movement of the rod 53 rotates the steering arm through the gear and drives the drag link.

The reactor/con communication passage 15 is connected to the
Pair of Pal 7”13 Glue Acuncong Chambers 43.4
4 to -qi.

That is, in the control valve casing 20 of the control valve 13, a pair of reactors 7je-) 27° 28 are formed in both sides, respectively, and are connected to the reactor chambers 43, 44, respectively. One of the 15 Reaxicon communication passages! 1'M is connected to the reactor controller port 27, and the other end is connected to the reactor controller port 28.

Of course, piping with a predetermined inner diameter and length is used for the reactor communication passage 15, but the control valve casing 20-! It may also be formed by drilling a hole inside the Takepower Solder casing.

The reaction force adjustment valve 16 is arranged in the reactor communication passage 15.

The reaction force regulating valve 16 is reciprocally slidable within the spool 6 damper and valve 0 caning having a spool chamber (not shown) and a pair of ports 54,55 communicating with the spool chamber. The spool is disposed in the spool and is configured with a spool that changes the cross-sectional area of the passage within the spool chamber in accordance with the reciprocating movement of the spool.

Therefore, depending on the reciprocating sliding of the spool, the port 4
The flow rate of the pressure oil flowing between the cylinders 54 and 55 is regulated, in other words, the pressure within the acquisition chambers 43 and 44 is regulated.

Of course, the reaction force adjustment valve 16 is connected to the pair of ports) 54.
If the flow rate of pressure oil flowing between 55 and 55 can be adjusted,
The form is arbitrary.

In addition, the reaction force adjustment valve 16 is controlled by a control system, which will be described later.
A servo motor (not shown) is built in as an actuator for sliding the spool back and forth in accordance with the output current from the unit 60.

Of course, in addition to the servo motor, it is also possible to use a stepping motor as the actuator.

The control unit 60 includes a wiper switch 61
．． and the vehicle speed sensor 62, and are sent to the servo motor to drive the servo motor in response to signals from them, in other words, to open and close the reaction force regulating valve 16. The output current is configured to control the output current.

The sonocontrol unit 60 mainly includes an input and output circuit, a memory circuit, an arithmetic circuit, a control circuit, etc., and its wiper switch 61° and vehicle speed sensor 62 are connected to its input circuit, and its reverse A servo motor built into the force regulating valve 16 is connected to its output circuit.

Therefore, in the combination of the control unit 60 and the vehicle speed sensor 62, the control unit 60 inputs the signal from the vehicle speed sensor 62,
An output signal is sent to the servo motor to change the amount of throttling at the reaction force regulating valve 16, resulting in...
The steering IO is configured to be vehicle speed sensitive, and its control unit 60. In the combination of the wiper switch 61 and the vehicle speed sensor 62, under the force of the wiper switch 61, the amount of throttle in the reaction force adjustment valve 16 becomes relatively large. Not only is it configured to be vehicle speed sensitive, but it is also configured to be a vehicle speed sensitive type that has a relatively large reaction force, taking into account that the resistance between the tires and the road surface is small when driving in the rain.

Next, to describe the driving of a cab-over type truck to which the above-mentioned power steering IO is applied, when driving at low speed on a sunny day, in other words, with the Wyno P switch 61 de-energized, the vehicle speed The signal from the sensor 62 is input to the control unit 60, which in turn sends an output current to the servo motor of the reaction force regulating valve 16, so that the spool of the reaction force regulating valve 16 slides. The cross-sectional area of the passage within the spool chamber has been widened.

In such a state, the flow rate of the pressure oil supplied from the oil pump 11 is adjusted by the flow control valve 12, and a predetermined flow rate of pressure oil is sent to the supply port 22 of the control valve 13.

Pressure oil sent to the supply port 22 is returned to the oil reservoir 56 side from the discharge port 23 when the control valve valve 31 is in the neutral position (/Cfft). When the valve spool 31 is slid to either side by the steering operation, the pressure oil is transferred to either one of the cylinder chambers 49, 50 of the war cylinder 14, depending on the sliding direction.
The signal is then sent to one side of the reactor chambers 43 and 44.

91n Ha, 'ctv control l-roll H hartsfu 0-
If the lever 31 is slid to the right in the figure, its supply 1
5-) 21;,-t control valve C through the spool groove 37 of the spool 31 to the power cylinder
The pressure oil is communicated with the port 26, and is sent to the cylinder chamber 49 of the power cylinder 14, so that the power piston 51 is slid to the left in the figure, and in other words, the power cylinder 14 is slid to the right.

When pressure oil is supplied in this way, a part of the pressure oil is
It is sent to the reactor control chamber 44 through the communication hole 42 and the bore 40.

The reaction force due to such steering is given by the pressure in the reaction chamber 44, but as mentioned above, when traveling at low speed, the passage cross-sectional area of the reaction force adjustment valve 16 is widened. Pressure oil in the reaction chamber 44 passes through the reaction force communication passage 15 and is sent to the reaction force action chamber 43 without being extremely throttled by the reaction force adjustment valve 16.

Of course, 'C control [F]ノ'? If the Rupu Suhoor 31 is slid as described, it will be ejected, I? −
23 is connected to the spool groove 36, so that the pressure oil in its reactor chamber 43 is transferred to the oil reservoir 56.
returned to the side.

Therefore, the pressure drop caused by the reaction force regulating valve 16 described above becomes small, and the pressure difference between the right and left reactor valves 43 and 44 becomes small, creating a large resistance to the sliding movement of the control valve spool 31. In other words, steering during low-speed driving is performed with a small operating force.

t*, So (7) Control O Noggles C Spool 31
is slid to the left in the figure, the supply row beat 22 is connected to the spool groove 38, the discharge port 23 is connected to the spool groove 37, and the pressure oil is supplied to the power cylinder 14 through the communication path 45°46. The cylinder 50 and the rear cylinder 43 are respectively sent, and the cylinder piston 51 is slid to the right in the figure, that is, the cylinder 14 is slid to the left.

Contrary to the case described above, the pressure oil in the reactor channel 43 passes through the reactor communication passage 15 and is sent to the reactor channel 44 without being extremely restricted by the reaction force adjustment valve 16. The reactor
The oil in channel '844 is in bore 40. It passes through the communication hole 42 and is returned to the oil reservoir 56 through the discharge port 1-23.5.

Therefore, as in the case described above, the pressure drop caused by the reaction force adjustment valve 16 becomes smaller, and the pressure difference in the left and right reaction chambers 43 and 44 becomes smaller, so that the control of the This does not create a large resistance to sliding, and steering at low speeds can be performed with a small operating force.

Of course, when the cab-over type truck is steered while stopped, the traveling speed is zero and the passage cross-sectional area of the reaction force adjustment valve 16 is widened to the maximum. Since the mutual pressure difference is extremely small, steering when the vehicle is stationary can be done with extremely little operating force.

Further, when the cab-over type truck travels at high speed, the control unit 60 inputs a signal from the vehicle speed sensor 62, and furthermore, the control unit 60 outputs an output current to the servo motor of the reaction force adjustment valve 16. As a result, the spool of the reaction force regulating valve 16 is slid, and the cross-sectional area of the passage in the spool chamber is narrowed.

As before, if the control pulp spool 31 is slid to either side, the cylinder chamber 49.5
Pressure oil is sent to either side of piston 5.
1 is slid, and a part of the pressure oil is sent to either of the reaction force adjustment chambers 43 and 44, but the reaction force adjustment valve 16 is closed.

- Because the cross-sectional area of the passage inside the le chamber is narrowed,
The pressure drop caused by the reaction force adjustment valve 16 becomes large, and the pressure difference between the left and right reactor chambers 43 and 44 becomes large, creating a large resistance to the sliding of the control pulp spool 31, which causes a problem during high-speed running. Relatively large operating force is required for steering, improving driving safety.

Furthermore, when the gap-over type truck drives in the rain, when the wiper switch 61 is activated, the respective signals from the wiper switch 61 and the vehicle speed sensor 62 are inputted to the control knee button 60. ,,
The control unit 60 of 'c sends an output current to the servo motor of the reaction force adjustment valve 16, and as a result, the amount of throttling in the reaction force adjustment ff16 increases relatively more than in the case described above.

Therefore, even if the cornering force is significantly reduced on a wet road surface compared to a dry road surface, the reaction force will be relatively large, resulting in a reduction in the resistance between the tires and the road surface when driving in the rain. Thus, changes in the steering force are avoided, in other words, the steering force remains substantially constant;
Be able to drive safely.

In the above embodiment 10, the control unit 6
0 is electrically connected to the wiper switch 61 and the vehicle speed sensor 62, and the power steering 10 is configured to be a vehicle speed sensitive type.
It is also possible to use an engine rotation sensor instead of the engine rotation sensor 2, in which case the power steering 10 is configured to be an engine rotation sensor.

According to this invention mentioned above, oil ponno 0, flow C control C pulp, control pulp
Glue a pair of glue on both sides of the spool.
lfi EZ) In a device consisting of a control valve and a power cylinder, the rear axicon communication path is
A pair of reactor chambers of the control pulp are provided to communicate with each other, and a reaction force adjustment valve is disposed in the reactor communication passage, and the control unit, wiper switch, vehicle speed sensor, engine It is electrically connected to a rotation sensor, etc., and controls the output current that opens and closes the reaction force adjustment valve according to signals from them.The power steering is simply vehicle speed sensitive or engine speed sensitive. Not only is it shaped, but it is also designed to have a relatively large reaction force, taking into consideration that the resistance between the tires and the road surface will be small when driving in the rain, so depending on the driving conditions of the vehicle, Appropriate reaction force is always obtained, reducing fatigue caused by steering operation, especially under conditions where the cornering force is extremely different, such as when driving on a sunny day and when driving on a rainy day.
The steering force becomes substantially constant, enabling safe driving, and the structure is simple and can be easily applied to conventional power steering, making it extremely practical.

[Brief explanation of the drawing]

The figure is a schematic diagram showing a specific example of power steering used in a vehicle of the present invention applied to a gap-over type truck. 10. Power steering used in a vehicle, 11
・Oil cylinder 7', 12... Flow control 0 valve, 13 ・Control 0 valve, 14 Power cylinder, 15... Rear axial control communication passage, 16
・Reaction force adjustment valve, 31...Control pulp spool, 43.44...-Reaction force adjustment chamber, 60
...Control unit, 61. Wiper switch, 62..Vehicle speed increase. -JL-1

Claims (1)

[Claims] Oil e-pump, flow [F] control pulp, control pulp with a pair of reactor chambers on both sides of the control-valve C spool, and a power cylinder used in a vehicle.・In the case of power steering, the rear axicon communication passage is
The control valve is provided to communicate with the pair of reactor chambers, and the reaction force adjustment valve is disposed in the reactor communication passage, and furthermore, the control unit is electrically connected to the wiper switch and the vehicle speed sensor. A power steering system used in a vehicle is characterized in that the output current for opening and closing a reaction force regulating valve is controlled according to signals from the power steering system connected to the power steering system.