JPS58149861A - Power steering used for vehicle - Google Patents

Abstract

PURPOSE:To adjust required force for steering a handle at high speed running slightly larger than at low speed running, by applying accurate reaction force in accordance with a rotary speed of an engine. CONSTITUTION:When a larger flow quantity of pressurized oil is fed from an oil pump 11, that is, when an internal-combustion engine is operated at a high speed, an oil return control spool 19 of a flow regulating valve 12 is moved to an outer side against a return spring 27 to communicate a pump port 14 to a suction port 15. That is, the pressurized oil fed to the port 14 flows in through fixed orifices 30, 31 of a separator wall 18 while being returned to a suction side of the pump 11 from the port 15, and is fed to supply ports 38, 39 from a port 17 while partially fed to reaction ports 47, 48 of a valve 34 from a reaction control port 29.

Description

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

Generally, this type of power steering has a flow control system that controls the flow rate of pressure oil according to the rotational speed of the internal combustion engine in order to stabilize the weight of the steering wheel when driving at high speeds, making it more stable than when driving at low speeds. Control pulp, so-called engine speed sensitive flow rate regulating valves, have been widely used.

Such an engine speed-sensitive flow regulating valve has an oil return control spool movably disposed within the pulp casing, and the oil return control spool is connected to the control valve spool. 〇It is equipped with a pin that passes through an orifice formed near the control pulp port, which connects the control pulp of the power steering device consisting of a cylinder, and its oil return valve.
) Most of them have a configuration in which the gap between the orifice and the pin can be adjusted according to the reciprocating sliding of the roll spool.

Therefore, when the flow rate of pressure oil supplied from the oil pump is low, the oil return control
Since the spool is hardly slid and its orifice is not severely constricted by its pin, its oil
Pressure oil at a flow rate corresponding to the pump rotation speed, that is, the engine rotation speed, is sent to the control valve spool side of the power steering link device, and the steering is placed in a state where it can be rotated with a small operating force, and When the flow rate of the pressure oil supplied from the oil pump is large, that is, when the internal combustion engine is operating at high speed, the Kiniha Sono Oil's turn fist/troll spool slides, and this sliding causes the pressure oil to increase. part is returned to the suction side of the oil pump, and the orifice is further throttled by the pin, thereby delivering a reduced flow of pressure oil to the control valve spool side of the power steering system.

However, this method of reducing the flow rate of pressurized oil sent to the control pulp spool side of the steering link system during high-speed driving is difficult to use when combined with a spring reaction type power steering system. However, in combination with a hydraulic reaction power steering device, it is impossible to change the weight of the steering wheel. To explain the reason in detail, when a car changes course, the load acting on the steering wheel is the same regardless of the presence or absence of an engine speed-sensitive flow control valve; This is because the power m-steering output required to turn the engine is equal to the product of the pressure-receiving area of the nower piston and the hydraulic pressure acting there.

In other words, in the case of a hydraulic reaction force type, the hydraulic pressure is guided to the rear axicon-champer, and the hydraulic pressure and the rear axicon-champer are
The weight of the handle is the product of the pressure receiving area of the control valve Sgur in the chamber. Therefore, the weight of the handle is not affected by the flow rate.

In addition, in the case of the spring reaction type, the control pulse sole is slid with the stroke necessary to generate the hydraulic pressure acting on the power piston, and the distance of that stroke and the spring constant of the reactor gooseberry The product is the weight of the handle.

Therefore, the weight of the handle is affected by the flow rate since its stroke requirement varies with the flow rate.

An object of the present invention is to achieve sufficient effects even when an engine speed sensitive flow rate control valve is applied in combination with either a spring reaction type power steering device or a hydraulic reaction type power steering device; To provide a power steering system which makes the weight of the steering wheel more penetrating during high-speed running than when running at low speed, makes it more stable, has a simple structure, and is used in a low-mounted vehicle.

To solve these problems, the power steering used in the vehicle of the present invention consists of a power steering device consisting of an oil pump, a flow control palft, and a control palfuoyohi power cylinder. At the control/group port of the flow control Φ valve, the power
The flow rate of pressurized oil that can properly drive the power piston of the steering device is obtained, and the flow control valve's flow control valve controls the rotation speed of the internal combustion engine that drives the oil pump. A corresponding pressure signal is obtained, and the pressure signal force is configured to act appropriately as a reaction force in the power steering device, so-called steering weight.

Hereinafter, preferred specific examples of the power steering system used in a vehicle according to 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 includes an oil pump 11 driven by an internal combustion engine (not shown) mounted on the cab-over type truck, and a flow control valve II! , a power steering device consisting of a control valve 34 and a power cylinder 31.

The oil pump 7'll is constructed in the same manner as the oil pump used for existing engine steering, so a description of its construction will be omitted.

The flow control valve 12 is installed independently in the hydraulic piping on the downstream side of the oil Φ pump 11, or
The pump 11 or the inlet side boat 14, which is integrally incorporated in the oil pump 11 or the oil steering device, is connected to the discharge side of the oil pump 11, and the power pump 14, which will be described later,
δ tearing device [O=+n) Control valve port 1 connected to roll valve spool 4'e side
7. A suction port 15 connected to the suction side of the oil pump 11, a valve chamber 16 communicating between the pump pump 14 and the suction port 1, and a valve chamber 16 connected to the suction side of the oil pump 11. a reactor control port 29 formed near the outlet port 17; a fixed orifice 30 as a throttle formed in the partition wall 18 that partitions the control valve port 17 and the valve chamber 16; 31 Sono Control) Z Lube Po 1
Metering formed on the venturi at 17
The orifice 32 and the pilot pilot communication passage connecting the metering orifice 32 and the outer part of the valve casing 16: an oil return control valve 1 reciprocally slidably disposed within the groove chamber 16 to control communication between the port 14 and its suction ports 1-15;
9 and is configured as CV.

That is, the valve casing 13 corresponds to the lower part of the casing of the oil pump 11, and the valve casing 13 is connected to the discharge side of the oil pump 11 and has a substantially vertical direction. The control Φ pulp port F17 extends outward in a substantially vertical direction from the lower part of the pump port 14, and the suction side of the oil pump 11. A suction port 15 is formed in parallel with the pump port 14 and extends upward in a substantially vertical direction.

Additionally, a nokulp chamber 16 is laterally formed in the nokulp casing 13 so as to communicate the pump port 14 with the suction port 15.

Such a valve chamber 16 and its control
A partition wall 18 is integrally formed between the valve and the port 17, and fixed orifices 30, 31 as throttles are formed in each partition wall 18.

Additionally, a venturi is formed in the control valve port 17 and a metering orifice 32 is formed in the throat of the venturi.

The metering orifice 32 is connected to the outer portion of the valve chamber 16 via a pilot communication passage 33.

Also, in the valve chamber 16, the position near the fixed orifice 30, 31, that is, the pump port! In the valve casing 13 at a position corresponding to the lower part of 4, there is a reactor control port 29.
is formed.

In the valve chamber 16 of the valve-casing 13 constructed as described above, an oil return control spool 19 is arranged so as to be able to slide back and forth.

The sono-oil return control spool 19 is formed into a substantially cylindrical shape with an IJ-F valve chamber 21 inside, and an IJ-F pulp φ chamber 21 and an IJ-F pulp φ chamber 21 on the rear end and upper outer peripheral surface. A pressurized oil inlet 22 and a pressurized oil outlet 23 are formed to communicate with each other.
a spool body 2o with a stopper 26 fixed to the tip;
A pole poppet 24 for opening and closing the pressure oil inlet 22 in the relief valve chamber 21 and a ball poppet 24 arranged in the relief valve chamber 21 so as to press against the pressure oil inlet 22. The return spring 25 is made up of many different types.

An oil return control spool 19 so configured is arranged within the valve chamber 16 of the valve casing 13 and is cooperated with the sonooil return control spool 19 to control the valve. A back pressure chamber 28 is formed in a portion closer to the outside of the channel +16.

Of course, the back pressure chamber 28 is connected to the pilot communication passage 3 mentioned above.
3 to a metering orifice 32.

In addition, the back pressure chamber 28 contains the oil return
A return spooling 27 is arranged that presses the control spool 19 inward.

Therefore, the oil return controller/14 stool 19 is normally pressed inward by its return spring 27, and the stopper 26 at the tip of the spool body 20 is placed in contact with the partition wall 18. It will be destroyed.

Of course, in such a state, the communication between the pump port 14 and the suction port 15 is cut off.

The power steering device is a hydraulic reaction force type control valve 34. ! :, power cylinder 3
It is composed of 7.

The casing 35 of the sonocontrol valve 34 is provided with a spool chamber 36 for the control valve spool 49 (D) and its power cylinder 3
7's Power Cylinder Fist＼-Thing 43 is a power cylinder fist.
Equipped with a cylinder @ gore for the piston 62, and
The power cylinder casing 43 is integrally formed with the casing 35 of the control pulp 34.

A pair of supply ports 38 and 39 are formed on both sides of the casing 35 so as to communicate with both ends of the spool chamber 36, respectively. Of course, the supply ports 38 and 39 are connected to the control pulp port 17 of the above-mentioned flow rate regulating valve 12 via the oil supply pipe 67.
are connected to each.

In addition, in the casing 35, the pair of supply ports): (between 8 and 39 is the spool chamber 36).
40.41 A pair of discharge ports)
are formed at appropriate intervals. Of course,
The discharge port 40°41 is connected to the drain oil pipe 68 through
In such a casing 35 connected to the suction side of the oil bonder 11 mentioned above, its supply port) $8. A pair of power cylinders 42.4 are formed between the power cylinder 19 and its discharge port 41.42 so as to communicate with the spool chamber 36.

Furthermore, a pair of column-shaped fixed type reactor grungers 45, 46 are fixed to the inner walls on both sides of the spool channel 36 so as to project toward each other.

The fixed type reactor sylangers 45 and 46 are equipped with reactor e-boats 47 and 48 inside, respectively. That is, its Reaxcon port 47.4
8 is connected at one end to the outer end of the A4 guides 45, 46, and at the other end to the outer peripheral surface of the spool guide 45, 46 near the inner end.

Also, its fixed type reactor plunger 45.46
A ring groove 58.5 is formed on the outer periphery of the inner edge of the inner end so as to be connected to the reaction/11 boats 47, 48.
9 are formed respectively.

The ports 47 and 48 of the reactor in the fixed reactor plunger 45° 46 are connected to the above-mentioned flow rate regulating valve 12 via the 1 reaction piping 69.
are respectively connected to the Reaxcon control ports 29 of the.

In the spool chamber 36 of the casing 35 configured in this way, a control pulp spool 49 that is slid in response to a steering operation is arranged so as to be able to reciprocate.

The sonocontrol pulp spool 49 is drilled from both ends toward the center with an inner diameter that can accommodate the reactor plunger 45, 46 and an appropriate depth to form reactor chamber holes, respectively. , Land hoods 0 and 71 are respectively formed by grading the insides of the holes formed in this manner.

The Yonacontrol pulp spool 49 is reciprocally slidably disposed within the suzo p-chamber 36 so as to accommodate a Reaxcon plunger 45° 46 at each end. Of course, the fixed type reactor granger 45 and 46 have a function as a spool guide that smoothly guides the reciprocating movement of the control pulp spool 4g.

Therefore, in such a situation, the control
Inside both pulp spools 49 are a pair of one-way axle cylinders with lands 70,71, cooperating with the end faces of their reaction cylinders 45,46.
5o and st are respectively formed.

Of course, Seo's Control Nokurubu Stool 49 is
The outer periphery is provided with a plurality of spool grooves 52, 53, 54, 55 formed at appropriate intervals in the axial direction.

The inner spool grooves 5 and 55 are respectively connected to the reactor channels 451 and 50 located on opposite sides of each other via a pair of reactor communication passages 56 and 57.

In addition, the above-mentioned Reaxicon Control Pulp 4
At almost the center of 9 is the 1) Acshore control/? Pin 6 for resetting Lube 49'ka
6 is installed.

Of course, one end of the bin 66 passes through the casing 35 and is connected to the steering shaft (not shown) so as to be driven in response to a steering operation.

Therefore, the control valve spool 49 is slid back and forth by the steering operation.

Depending on such reciprocating sliding, the supply ports 38 and 39 are connected to the exhaust ports 41 and 42 or the power Φ cylinder.
It is switched and connected to ports 42 and 43.

A power piston 62 is arranged in the cylinder bore of the power cylinder casing 43 of the power cylinder 37 so as to be able to reciprocate. It is divided into 73 sections.

The cylinder chamber '12. '13 connects the power to the control valve 34 through the communication path 60°61.
cylinder ports) 42 and 43, respectively.

Of course, the tip of the operating rod 63 fixed to the power piston 62 and protruding outside the power cylinder casing 43 is attached to the chassis frame 64 side of the cab-over type truck, and On the opposite side of the operating rod 63, the tip of the rod 65 fixed to the casing 35 is shown to schematically represent the operating resistance on the tire side.

Next, the operation of the power steering lO described above will be explained.

First, when the internal combustion engine of the cab-over type truck is operated and the oil pump 11 is driven, pressure oil corresponding to the rotation of the oil cylinder 7'll is supplied to the pump port 14 of the flow rate regulating valve 12. sent to.

When the flow rate of the pressure oil supplied from the oil pump 11 is low, that is, when the internal combustion engine is operating at low speed, the oil return
The control spool 19 is positioned on the inside (left side in the figure) by the return and spring 27, and even if it moves slightly outward (to the right side in the figure) depending on the flow rate of the pressure oil, it will not connect to the pump port 14. Since contact with Sakusho/Po 1-15 has been cut off, pressure oil...
Passing through fixed orifices 30, 31 in the partition wall 18, the control valve 34 forming part of the steering device passes from the control valve fist 17.
A portion of the pressure oil is sent to the rear control port 29 or the rear control port 17 of the valve 34, 47.

Sent to 48.

In such conditions, when the control valve spool 49 of the control valve 34 is in the neutral position, the pressure oil sent to its supply port 18.39 and the reactor port 47.48 is ,
The oil is returned to the suction side of the oil e-pump 1.1 from the discharge ports 40 and 41, but if the control φ noggle spool 49 is slid to either the left or right by steering operation, the supply port 38 or 39 is returned to the suction side of the oil e-pump 1.1. The pressure oil sent to the cylinder chamber '12. of the power cylinder 37.
Pressure oil sent to either the left or right side of the '13 and to its reactor port 47 or 48 is sent to the reactor chamber 50 or 51.

For example, Eva, sono control valve spool 49,
If slid to the right in the figure, the outer spool groove 53 is connected to the supply port 39 side, and the reaxicon chamber 51 is connected to the ring groove 59 of the reaxicon port 48. That is, its supply port 3
The pressure oil sent to the power cylinder 9 is sent to one cylinder chamber 73 of the power cylinder 37 via the spool groove 53 on the outside and the communication path 61, and the pressure oil sent to the rear axicon φ port 48 is sent to the cylinder chamber 73 of the power cylinder 37. The oil is in Reaxicon Chamber 5.
Sent to 1.

Therefore, the reaction force of the steering in such a state is given by the pressure oil sent to the reaction chamber 51, and the pressure oil sent to the reaction chamber 51, in other words, the reaction force of the flow rate adjustment valve 12. Since the pressure of the pressure oil sent from the fist control port 29 is approximately proportional to the rotation speed of the oil pump 11, when driving at low speed, the pressure of the pressure oil in the rear axle run chamber 51 is relatively low, and the control The fist valve spool 49 is placed in a state where it does not provide a large resistance to sliding and can be steered with a small operating force.

Of course, when the sonocontrol valve spool 49 is slid to the left in the figure, the operation is opposite to the above-described operation, so a description of such operation will be omitted.

Further, when the flow rate of the pressure oil supplied from the oil pump 11 is large, that is, when the internal combustion engine is operated at high speed, the oil return control spool 19 of the flow rate regulating valve 12 is connected to the return spring 27.
The pump port 14 and the suction port 16 are brought into communication with each other by moving outward (to the right in the figure) against the flow.

That is, the pressure oil sent to the pump port 14,
While being returned to the suction side of the oil pump 11 from its suction port 15, it is sent from the partition wall trawl valve port 17 to the supply boat 38, 39 of the control pal 7''34, from the reactor control port 29 to the reactor port 47,48 of its control fist valve 34.

Of course, as in the case described above, if the control valve spool 49 of the control valve 84 is slid to either the left or the right, the supply port 38''! or The pressure oil sent to the cylinder chamber 72 or 7 on either the left or right side of the power fist cylinder 37
3 and also reaction/# boat 47 or 4
The pressure oil sent to 8 is sent to a reactor chamber 50 or 51.

Therefore, during high-speed driving, the pressure of the pressure oil in the reactor chamber 50 or 51 becomes relatively high in approximately proportion to the rotational speed of the oil pump 11, so that the control valve spool 49 This is a state in which the steering wheel becomes a resistance to the sliding of the steering wheel and can be steered with a relatively large operating force, i.e., the weight of the steering is heavy even when driving at low speeds, and driving stability is improved when driving at high speeds. According to the power steering used in the vehicle of the present invention, the power steering device includes an oil pump, a flow control valve, a control fist valve, and a power cylinder, and its flow control device.・Pulp power, control The internal combustion engine that drives the oil pump in the control horde provides a flow rate of pressurized oil that can properly drive the power piston of the power steering device. The power steering device transfers pressure oil from the control valve port of the flow control valve to the sliding of the control parboosol. The system is configured so that pressure oil is sent to the power cylinder according to the engine speed, and pressure oil from the rear auxiliary control port is sent to the rear auxiliary chamber, so the weight of the handle can be adjusted according to the engine speed. In other words, when driving at low speeds, light and quick steering operations are possible, reducing fatigue caused by steering operations, and
When driving at high speeds, the weight of the steering wheel is reduced compared to when driving at low speeds, improving driving stability and making it extremely practical.

[Brief explanation of the drawing]

The figure is a schematic diagram showing a specific example of the power steering system used in the vehicle of the present invention applied to a cab-over type truck. 10...Power steering used in vehicles, 1
1...Oil pump 7', 12...Flow control paper pulp, 13...Valve fist casing, 14
...Pump port, 15...Suction port, 16...Pal f-chamber, 17...Control fist valve port, 19...Oil return lI
Control spool, 29... Reaxcon control port, 30. 31... Fixed orifice, 34... Control pulp, 35... Casing, 36... Spool chamber, 37... Power Fist cylinder, 38.39... Supply port, 40.4
1... Discharge port, 42, 43... Power cylinder O port, 44... Power cylinder casing, 45° 46... Fixed type rear axicon e granger,
47゜48... Reaxon port, 49... Control 1 noclepusdale, 50, 51... Reaxon chamber pool groove, 56.57... Reaxon communication passage, 62... Power piston , 63
...butshu rod.

Claims (1)

[Claims] An oil pump, a valve chamber, a pump boat connected to the oil pump in the valve chamber, and a suction boat connected to the oil pump.
A valve casing consisting of a control boat, a control Φ/J-lube boat connected to its valve chamber, and a restriction located in its valve chamber between the pump boat and its control 1 valve fist port. In order to adjust the discharge amount of pressure oil discharged from the sonocontrol valve boat and the return amount of pressure oil returned to the suction boat, a hydraulic oil is arranged to be reciprocally slidable within the valve chamber.・Return control stool and sonooil-reaxon mirrored in its valve chamber, facing its throttle side, so that it is always released from the return control spool. Between the other 70-〇 control valve and the spool chamber, the control valve of the flow control valve, and the pair of supply boats connected to both sides of the stool chamber, respectively, and their supply ports, If that snowluchan
f a control valve consisting of a pair of discharge boats connected to the suction side of the oil pump and a pair of power cylinder boats connected to the stool chamber between the supply port and the discharge boat; a casing and a control valve spool open at each end and reciprocally slidably disposed within its stool chamber for switchingly connecting its supply port to its discharge boat and power cylinder boat; , a pair of reactor chamber bores formed in the control valve stool, and the control valve spool is configured to switch and connect the reactor chamber bores to the discharge port in response to reciprocating sliding of the control valve spool. , a pair of reactor communication passages formed in the control valve spool and the reactor converter chamber are respectively fitted into A,
A pair of fixed reactor granjats are arranged opposite each other in the spool chamber to form a pair of reactor chambers in the control valve spool.
A reactor port formed in the fixed reactor syringe and a null control valve in the casing of the control valve to allow pressure oil from the pulp reactor control hoard to be delivered to the reactor chamber. a power cylinder casing integrally formed and having a cylinder bore connected to a pair of power cylinder e-ports of the control pulp; A power piston whose cylinder is arranged so as to be able to reciprocate and slide within the cylinder gear so as to form a pair of cylinder chambers inside the cylinder gear, and an operating rod connected to the power piston.・Power steering used in vehicles including cylinders.