JPS60143181A - Control valve for power steering - Google Patents

Abstract

PURPOSE:To improve the stability of valve by forming a reaction communicating port into a hollow spool while inclining with proper angle against the axis of reaction chamber bore thereby producing vortex of pressure oil in the reaction chamber. CONSTITUTION:Reaction communicating port 19 and reaction bypass port 20 are formed into hollow spools 12 while inclining by predetermined angle against the axis of reaction chamber bore 29. pressure oil from an oil pump 42 will pass through the port 19 to produce vortex in the reaction chamber 28 where the reaction bypass port 20 is provided to be in reverse direction against the vortex. Consequently, the pressure oil will be hard to bypass through the port 20 to the suction side of pump 42 because of the vortex produced in the reaction chamber 28 resulting in prevention of vibration of spool 12 even upon abrupt function of valve 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control pulp used for /F quay steering of a vehicle. Regarding pulp.

Conventionally, in linkage-type power steering, the control valve has been configured as a vehicle speed-sensitive hydraulic reaction force type that changes the reaction force, that is, the steering force, depending on the vehicle's driving condition. Due to the valve's response (↓) and stability when operated rapidly, the structure has become complicated or compensation means have been required.

The purpose of the invention is to improve the static, dynamic and transient properties of pulp without complicating the structure, and to improve the stability of valves, especially when the steering wheel is operated suddenly. At the same time, the /l horn is used to suppress pulp motion and prevent the generation of noise due to pulp vibration.
Our goal is to provide control valves used in steering.

With these issues in mind, the control pulp used in the power steering of this invention has a reaction
The reaction chamber bore for the chamber is biased to the spool, and the pressure oil from the oil pump is controlled to flow from the oil pump to the i4 cylinder through the flow control valve. A reaction communication port leading to the reaction chamber is formed on the spool at an appropriate angle to the axis of the reaction chamber bore to create a vortex flow within the reaction chamber. I have to.

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

The figure shows a specific example 1O of the control valve of the present invention, which is applied to construct a speed-sensitive link type power steering system 40 for a cab-over type truck.

The control valve 10 is connected to a link lever (not shown) connected to a knuckle arm (not shown) via a drag link (not shown) for front wheel steering.
a cylinder 46 pivotally connected to a cylinder body 46; a power piston 48 disposed for reciprocating sliding in a cylinder bore 47 of its cylinder body 46;
M! It is assembled into a power cylinder 41 consisting of an operating rod 49 which is fixed to the nozzle piston 48 of C and whose other end is pivotally connected to the chassis side, a convenzing rod (not shown), and a pitman arm. (not shown), the steering wheel is operated via a manual steering gear 7j?tx (not shown), and in the hydraulic circuit of the power steering 40, hydraulic piping 44. 45, the pressure oil is discharged from the oil pump 42 and the flow rate is adjusted by the flow control valve 43.
power cylinder 41 and its power cylinder 4
This is to return the pressure oil worked in step 1 to the suction side of the oil pump 42, and the valve body 11 and valve body 12
and a pair of reaction shafts 13 and 13.
It includes a plunger 14, 15, a pair of pusher stoppers 16, a reaction strip ring 17, and a reaction force adjustment valve 18, and a rear connection communication port 19 and a reaction relief port 1-20 are formed in the spool 12.

The valve body 11 is assembled into the cylinder body 46 of the power cylinder 41 and opened into the spool chamber 21 . Knob port 22, a pair of power cylinders, IP-1-23゜24, a pair of tanks.
25, 26 and 27 ports.

In addition, the pressure oil whose flow rate is adjusted by the flow control valve 42 is transferred to the cylinder of the power cylinder 41.
The pump port 22 formed in the valve body 11 is on the supply side of the hydraulic line 44 for supplying the chamber 50,51, and the power cylinder port 23, 24 is on the supply side of the hydraulic line 44. .45 cylinder side, and its tank ports) 25 and 26 are respectively connected to its hydraulic piping 45.

The spool 12 is formed hollow, and the spool 12 is hollow.
It is arranged so as to be able to slide back and forth in the chamber 21, and forms a reaction chamber 28 inside.

The hollow spool 12 also has a large diameter plunger hole 30 at one end of the reaction chamber 28.
The other end of the reaction chamber 28 is formed with a small-diameter bore 31, a reaction communication port 19 connecting the pump port 22 with the reaction chamber 28, and a reaction communication port 19 connecting the reaction chamber 28 with the reaction chamber 28. - Equipped with a reaction escape port 20 that communicates with port 27.

The reaction communication 5e-zcs transfers pressure oil from the oil pump 042 to the reaction chamber 2.
formed in the spool 12 at a predetermined angle to the axis of the reaction chamber bore 29 so that when guided into the reaction chamber 28, a vortex is generated in the reaction chamber 28; This makes it difficult for the pressure oil in the reaction chamber 28 to escape through the reaction relief port 20 to the reservoir, that is, the suction side of the oil pump 042, and adds resistance to the pressure oil. Of course, the angle of the rear communication port 19 is mainly determined by the steering wheel.
It is necessary to suppress valve vibration when O is suddenly operated! ``1) Determined by the strength of the flow.

On the other hand, I missed that rear end, I? - The engine 20 is configured such that pressurized oil escapes from the reaction chamber 28 by the suction side of the oil pump 42.
It is formed in the stool 12 at a predetermined angle to the axis of the reaction chamber bore 29 in a direction opposite to the vortex flow in the reaction chamber 28 . Of course, the leak port 200
The angle is relative to the reaction communication port 19,
The steering wheel pressure is determined by the pulp vibrations that the control valve IO is intended to suppress when the valve is actuated rapidly.

Furthermore, the hollow stool 12 is the]? Ring groove 3 forming a valve oil chamber for switching and connecting pump port 22 to its power cylinder port 23,24
2.33.

The spool 13 has one end passed through the hollow spool 12, and both ends of the spool 12 are arranged so that the spool 12 is slid back and forth into the spool chamber 21. The spool 12 is fixed to a pair of spools 34, one end of which is located at one end, and the other end of which is connected to a connecting point.

Furthermore, the spool shaft 13 is fitted with a bolt fitted onto one end side of the spool shaft 13 so that the spool shaft 13 is located between the spool stoppers 34. The stool 12 is sandwiched between a pair of spool stops 34 fixed to one end side of the stool shirt 13 by a sleeve-shaped spacer 36 that can be rotated, and a nut 37 that is screwed to one end of the stool shaft 13. Attach that stool 1
Fix 2.

The spool stoppers 34 are formed into plate shapes, and have two small holes 35 opened in the stopper surface at predetermined positions and at a predetermined distance from each other.

The reaction plunger 14,15 is formed into a large diameter one and a small diameter one, and the large diameter reaction plunger 14 has a large diameter plunger bore 30 and a seat 36 on the stool 13. The small diameter reaction planter 15 is reciprocally slidably fitted to the small diameter 70 lantshear bore 31 and the spacer 36 on the stool shaft 13 and is formed within the hollow stool 12. The reaction chamber 28 is closed.

As such, the reaction plungers 14 and 15 are designed to have a large diameter and a small diameter. When the power cylinder 41 extends, the steering feels heavy, and when the power cylinder 41 extends, the driver feels the steering is light. The purpose is to equalize the forces.

That pair of plunger stones? 16 consists of two pins protruding from both inner and upper end faces of the spool chamber 21, and these pins are passed through the small holes 35 of the spool stone or 34, and are inserted into the corresponding large diameter and small diameter reaction bars. The tips of the plungers 14 and 15 are abutted to restrict the movement of the reaction plungers 14 and 15 toward the inner end surface of the spool chamber 21, and as the spool shirt 13 moves, the reaction springs 17 to give a pumping action to the reaction plungers 14 and 15 to compress the oil filled in the reaction chamber 28;
Change the reaction force felt by the stool/shirt) 13.

The reaction spring 17 is arranged between the reaction plungers 14.15 in place of the spool shaft 13, i.e. the seat 36, and imparts a pumping action to the reaction plungers 14.15; It also functions as a neutral stellium for the valve.

The reaction force W regulating valve 18 is disposed in a reactor passage 38 consisting of a pipe connecting the reactor port 27 of the valve body 11 to the hydraulic pipe 45, and the pressure oil in the reactor chamber 28 is diverted to oil. - Adjusts the amount of oil released to the suction side of the pump 42, changes the pressure in the reactor chamber 28, and controls the reaction force applied to the spool shaft 13, and the spool chamber (not shown); a valve body having a pair of ports 39,40 in communication with its spool chamber; a spool (not shown) that changes the cross-sectional area of the passageway in the stool chamber, and the spool is slid back and forth into the stool chamber to change the cross-sectional area of the passageway in the spool chamber, depending on the traveling speed of the truck. Change that port 39゜4
Adjust the flow rate of pressure oil flowing between the hollow spool 1
2 is configured to vary the reaction force generated by the pressurized oil in the reactor chamber 28 of the second reactor.

Furthermore, in the reaction force adjustment valve 18, when the truck is traveling at low speed, the cross-sectional area of the passage is widened, and when the truck is traveling at high speed, the cross-sectional area of the passage is narrowed. The spacer is also driven by an actuator, e.g., a servo motor, and the servo motor receives a signal from a vehicle speed sensor (not shown). It is configured to be driven in accordance with the signal of.

Next, the operation of the power steering 40 configured as described above and incorporating the control valve IO and its control valve IO will be described in response to the driving conditions of a cab-over type truck. If the oil pump 42 is in operation, the oil pump 42 is driven, and the flow rate of the pressure oil supplied from the oil pump 042 is adjusted by the flow control valve 43, so that a predetermined flow rate of the pressure oil is controlled by the control valve 10. Pump moon? -1-22.

If the hollow spool 12 is placed in the neutral position, the pressurized oil sent to the pump port 22 is mainly sent to the pump port 1-25, 26 through the hydraulic piping 45, as shown in the above. From oil, -1? It is returned to the suction side of the engine 42, but the steering wheel is steered, and the suction shaft 13 is moved through the manual steering gear box, pitman arm, and concentrating condo. If the hollow spool 12 is slid in the direction of the movement of the spool 13, the pressure oil will flow into the hydraulic pipe 4 according to the movement of the hollow spool 12.
4. Nokwar cylinder 41 via the cylinder side of 45
one of the cylinder chambers 50, 51, and
is sent to the reactor chamber 28.

The reaction force against the steering is generated by the reactor chamber 28.
The pressure and vortex flow within the reactor is provided by the reactor communication and relief ports 19,20 and the reactor spring 17.

In such an operation of the power steering 40,
If the truck is driven at a low speed, the servo motor is driven in response to a signal from the vehicle speed sensor, and the spool of the reaction force adjustment valve 18 is slid, so that the passage cross-sectional area in the spool chamber is relatively wide. has been done.

Therefore, the oil in the reactor chamber 28 is /
11° filtration and reaction missed, I'? ) flows into the reaction relief port 20, the reaction conduit 27, and further flows through the reaction conduit passage 38 to the suction side of the oil bonnier 42, so that the The oil does not provide much resistance to the sliding motion of the rear axicon plunger 14 or 15, and steering during low speed running is performed with a small operating force.

Of course, if the truck is steered while stopped, the traveling speed is zero and the passage cross-sectional area of the reaction force regulating valve 18 is maximized, so that the reaction force adjusting valve 18 is steered.
The internal pressure becomes close to atmospheric pressure, allowing for deep cutting, width closing,
Turning and turning can be done with a small amount of force.

Well, if the truck is traveling at high speed, the servo motor is driven in response to the signal from the vehicle speed sensor, and the spool of the reaction force adjustment valve 18 is moved to the spool.・The cross-sectional area of the passage inside the chamber is narrowed.

Therefore, the oil in the reactor chamber 28 is
A vortex or a reactor escape oriented in the opposite direction to the vortex, I? - in addition to the reaction force adjusting valve 1
8, the oil pump 42 is further returned to the suction side and becomes a hub.
The oil in the chamber 28 is transferred to the reactor plant 14.
Alternatively, there will be a large resistance to the sliding movement of 15, and as a result, steering at heavy speeds will be performed with a relatively large operating force. In this way, a relatively large operating force is required for steering during high-speed driving, and driving stability is improved.

Unfortunately, the power steering 40 operates as described above when the truck is running at low speeds, high speeds, or when the truck is stationary. Therefore, when the power cylinder 41 in the power steering 40 retracts and extends, the difference between the operating force for turning right and the operating force for turning left becomes extremely small. For example, the steering forces for turning right and turning left are equalized. As a result, this power steering 40:
This relieves the driver from the physical fatigue of steering a truck.

Furthermore, when the truck is running at low speeds, high speeds, or when the truck is stationary, when the steering wheel 40 performs the above-mentioned operation, even if the steering wheel is suddenly operated, the rear axicon chamber 28 The vibration of the hollow stool 12 is suppressed based on the resistance of the vortex flow in the hollow stool 12 due to the Reaxcon relief port 20 directed in the opposite direction to the vortex flow, and the vibration damping effect of the pulp itself provided in this way suppresses the vibration of the hollow stool 12. , the occurrence of grinding noise due to valve vibration is prevented.

In the above-mentioned specific example 1O, the reaction force adjustment valve 18 was explained as one that adjusts the throttle amount according to the traveling speed of the cab-over type truck, that is, the vehicle speed, It is also possible to configure the throttle amount to be adjusted according to the number of rotations.

In that case, the servo motor that drives the reaction force regulating valve 18 will be driven by a signal from an engine speed sensor located at the transmission.

As mentioned above, a single reactor chamber 2
The control valve 17C with reactor chambers on both sides of the spool can also be applied to the control valve 17C with reactor chambers on both sides of the spool, in which case both action
The chambers are connected to each other through a communication path, and a reaction force adjustment valve is disposed in the communication path to adjust the reaction force, so the reactor release port 20 is for the communication path. ) will be applied.

According to the above-mentioned invention, a rear axicon communication port is formed in the spool at an appropriate angle to the axis of the rear axicon chamber bore, and is connected by a jet of pressure oil introduced from an oil pump into the rear axicon chamber. A vortex is generated in the reactor chamber, which creates resistance to the oil in the reactor chamber, and when the reactor relief port is in the opposite direction to the swirl, the reactor is removed from the reactor chamber. The stool is formed at an appropriate angle to the axis of the valve, making it difficult for the oil to escape from the reactor chamber to the suction side of the pump, so the valve itself has a damping effect, and the steering wheel Therefore, even if the control or valve is suddenly operated, the vibration of the stool is suppressed, so-called pulp vibration is suppressed,
The generation of noise due to the valve vibration is prevented, and the steering force for right-hand and pressure-cutting is equalized, thus improving the static, dynamic, and transient characteristics of the pulp, and improving the stability of the pulp. As a result, the optimum reaction force is obtained and the steering is stabilized, depending on the driving condition of the vehicle.
For drivers, it goes without saying that the fatigue caused by steering operations is reduced and driving becomes safer.Furthermore, a pair of rear axicon plungers open the rear axle chamber (as in the AU). It fits into the pickled snort so that it can slide back and forth, and it has a large diameter and a small diameter, so when the power cylinder retracts and extends, the operating force for right-hand cuts and pressure cuts are reduced. In other words, the steering force of the cloth cutting 9 and the pressure cutting 9 are much more equalized, and as a result, the steering becomes more stable, and the driver is able to use his/her physical strength while steering. Freed from physical fatigue.

As mentioned above, from the specific examples of the present invention described with reference to the drawings, various design modifications and changes can be easily made by those who have ordinary knowledge in the technical field to which the invention pertains. Furthermore, the content of this invention can be easily replaced by an embodiment essentially the same as that invention that satisfies essentially the same problem as that invention and achieves the same effect as that invention. It will be done.

A general view showing a specific example of the conotrol pulp of the present invention applied to a linkeno-type power steering, FIG. 2 is a li+Ii side view taken along line 2-2 in FIG.
And Figure 3 is on line 3-3 of Figure 1? V+ shown as 9
) is an r-plane view.

lO control Pulp, 11...Pulp body,
12...Spool 0-le, 13...Spool °shaft l
-114,15...Reakunkon plunger, 16.
・Pair of plant stoppers, 17... Reaction spring, 18... Reaction force adjustment valve, 19 Reactor 7 connection i? -To, 20... Reactor release port, 4
0...power steering, 41 power cylinder,
42. Oil ponder, 43. Flow control pulp.

Claims (1)

[Claims] Preparing the action chamber bore on the spool, flow control,
In a device that controls the pressure oil that flows through the oil pump 70 to the Lapower cylinder, the pressure oil from the oil pump 70 is
Is it the reaction communication port that leads to the chamber?
to create a vortex within its reaction chamber.
A relative control valve used in power steering, characterized by being formed on its spool at an appropriate angle to the axis of its reaction chamber bore.