JPS643706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow rate regulating valve used in power steering of an automobile.

In general, this type of power steering often takes the form of a servo mechanism included in a manual steering mechanism, in which manual steering displacement is given to the servo mechanism as an input signal, and the output mechanism It is configured to be able to operate by following the displacement of.

Moreover, most of the power sources for the output mechanisms are hydraulic type, and therefore, an oil pump is usually used as the power source for the output mechanisms.

The above-mentioned flow rate regulating valve controls the flow rate of pressure oil supplied from such an oil pump, and the rotation speed of the oil pump caused by the flow rate of the supplied pressure oil changes to the rotation speed of the internal combustion engine. In idling conditions, the specified flow rate is ensured, and when the internal combustion engine is running at high speeds, unnecessary excess flow is returned to the suction side of the oil pump to reduce steering rotation. It is constructed so that the operating force required for the operation can be maintained constant.

However, since the flow rate of the pressure oil controlled by such a flow rate regulating valve is set in advance to a predetermined flow rate, the operating force required to rotate the steering wheel can be adjusted according to the driver's preference. It is difficult to adjust the weight of the steering wheel, and if the weight of the steering wheel is configured so that it can be adjusted manually by the driver, each driver may have a different sense of steering operation. However, it is possible to operate the steering wheel in an appropriate state with less fatigue. Especially in the case of trucks, the weight of the steering wheel can be adjusted according to the load capacity and the condition of the road surface. This makes it possible to drive less and safely.

The purpose of this invention is to use a power steering system that can adjust the weight of the steering wheel according to the driver's preference when operating an internal combustion engine at high speed, thereby reducing driver fatigue caused by steering operations. The purpose is to provide a flow rate regulating valve.

In view of the above problem, the flow regulating valve used in the power steering of the present invention has an inlet side port connected to the discharge side of the oil pump, and a power steering valve.
A valve casing with an outlet port connected to the reaction control valve side of the steering device and a bypass port connected to the suction side of the oil pump, and the inlet port connected to the bypass port. A valve chamber formed in the valve casing so as to communicate with each other, and a plunger formed in the valve casing so as to communicate an oil passage of the inlet side port which is upstream of the valve chamber with the outlet side port. An oil valve is reciprocally slidably disposed in the bore and in the valve chamber to adjust communication between the inlet port and the bypass port.
A return control spool, a metering orifice opened in the oil passage of the inlet port upstream of the valve chamber, and a communication passage connecting the metering orifice to the outlet port. plunger
A metering plunger is placed in the bore and is slid into the plunger bore to throttle and adjust the oil passage of the inlet port upstream of the valve chamber, and the oil return control spool. A pilot communication passage that cooperates to supply reaction control valve side pressure oil of the power steering device to a back pressure chamber formed in the valve chamber, and a return spring disposed in the back pressure chamber. It is composed of the following.

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

The figure shows a specific example 10 of the flow regulating valve used in the power steering of the present invention.

The flow rate regulating valve 10 used for the power steering may be provided independently in the hydraulic piping downstream of the oil pump (not shown), or may be integrated into the oil pump. , an inlet port 12 connected to the discharge side of the oil pump, and a reaction control port 12 of the power steering system (not shown).
A valve with an outlet port 13 connected to the valve (not shown) side and a bypass port 14 connected to the suction side of the oil pump.
A casing 11 and its inlet port 12 are connected to its bypass port 14 to connect its valve.
Valve chamber 1 formed in casing 11
5, and the oil passage of the inlet port 12 which is upstream of the valve chamber 15 is connected to the outlet port 1.
3 and a plunger bore 16 formed in its valve casing 11 in communication with its valve casing 11;
an oil return control spool 17 that is reciprocally slidably disposed in the chamber 15 and adjusts communication between the inlet port 12 and the bypass port 14; and the valve chamber 15.
A metering orifice 27 opened to the oil passage of the inlet port 12 upstream of the plunger bore 16 and a communication passage 28 connecting the metering orifice 27 to the outlet port 13 are disposed in the plunger bore 16. and a metering plunger 26 that is slid into the plunger bore 16 and throttles and adjusts the oil passage of the inlet port 12 upstream of the valve chamber 15.
and the valve chamber 1 in cooperation with the oil return control spool 17.
a pilot communication passage 32 for supplying reaction control valve side pressure oil of the power steering device to a back pressure chamber 31 formed in the engine 5;
It was manufactured including a configuration with a return spring 33 disposed in the back pressure chamber 31.

Of course, the flow regulating valve 10 used in the power steering according to the present invention shown in the figure
is integrated into the oil pump at a suitable location, for example in the lower part.

That is, the valve casing 11 corresponds to the lower part of the casing of the oil pump, and is connected to the discharge side of the oil pump and has an inlet port 12 extending upward in a substantially vertical direction. is connected to the reaction control valve (not shown) side of the power steering device (not shown), is spaced apart from the inlet side port 12 laterally at an appropriate distance, and extends downward in a substantially vertical direction. and a bypass port 14 connected to the suction side of the oil pump and extending upward in a substantially vertical direction alongside the inlet port 12. .

Of course, the outlet port 13 is connected to the reaction control valve side of the power steering device via a hydraulic pipe (not shown).

A valve chamber 15 is laterally formed in the valve casing 11 to communicate the inlet port 12 with the bypass port 14 .

Of course, the valve chamber 15 connects its inlet port 12 to its bypass port at one end.
A hole is formed laterally from one side of the valve casing 11 so as to communicate with the port 14, and the open end side is closed with a plug (not shown).

Further, a plunger bore 16 is laterally formed in the valve casing 11 at a position above the valve chamber 15 so as to communicate the inlet side port 12 with the outlet side port 13. There is.

That is, the plunger bore 16 connects the inlet port 12 to the outlet port 1 at a position corresponding to an upper position than the valve chamber 15.
3 by drilling a hole laterally from the other side of the valve casing 11.

Furthermore, a pilot communication passage 32 is formed in the valve casing 11, which communicates the inner side of the plunger bore 16 with the outer side of the valve chamber 15 described above.

Valve casing 11 so configured
An oil return control spool 17 for controlling communication between the inlet port 12 and the bypass port 14 is reciprocatably disposed in the valve chamber 15 of the valve chamber 15 .

The oil return control spool 17 has a relief valve chamber 1 inside.
9, the rear end is formed into a substantially cylindrical shape, and
A pressure oil inlet 20 and a pressure oil outlet 2 are connected to the relief valve chamber 19 on the upper outer circumferential surface.
1 is formed respectively, and a stopper 2 is provided at the tip.
5 is integrally formed with the spool body 18; a ball poppet 22 for opening and closing the pressure oil inlet 20 within the relief valve chamber 19;
It comprises a valve seat 23 and a return spring 24 disposed within the relief valve chamber 19 so as to press the ball poppet 22 against the pressure oil inlet 20.

If the oil return control spool 17 so configured is placed in the valve chamber 15 of the valve casing 11, it will cooperate with the oil return control spool 17 to control the valve.・Chayamba 1
A back pressure chamber 31 is formed in a portion closer to the outside of 5.

Of course, the back pressure chamber 31 is communicated with the inner portion of the plunger bore 16 via the pilot communication passage 32 mentioned above.

Further, a return spring 33 is arranged in the back pressure chamber 31 to press the oil return control spool 17 inward.

Therefore, the oil return control spool 17 is normally pressed inward by the return spring 33, and the stopper 25 at the tip of the spool body 18 is in contact with the inner end surface of the valve chamber 15. placed.

Of course, in such a state, the inlet port 12
Communication with bypass port 14 has been severed.

Further, a metering plunger 26 is arranged in the plunger bore 16 of the above-mentioned valve casing 11 so as to be able to slide back and forth.

The metering plunger 26 is formed into a substantially cylindrical shape with a spherical surface at the tip, a metering orifice 27 is formed at the tip, and the metering plunger 26 is formed inside. When reciprocally slidably disposed in the plunger bore 16, a communication passage 28 is formed that connects the metering orifice 27 to the outlet side port 13 and the pilot communication passage 32, respectively.

That is, the communicating passage 28 is formed in a hollow shape so that the inside of the metering plunger 26 communicates with the metering orifice 27, and downward passages 29 and 30 are provided at the front and rear ends of the hollow part. The metering orifice 27 is connected to the outlet port 1 by forming the metering orifice 27.
3 and the pilot communication path 32, respectively.

Of course, the metering plunger 26 is located at the upper end of each of the outlet side port 13 and the pilot communication passage 32.
6, always close its metering orifice 27 to its outlet port 13.
Long grooves 34 and 35 are formed along the sliding direction so as to communicate with the pilot communication passage 32 and the pilot communication passage 32, respectively.

Also, as such, its plunger bore 16
and the plunger bore 1
6 to throttle and adjust the oil passage of the inlet port 12 upstream of the valve chamber 15.
The sliding position of the valve is regulated by a lock ball 39 and a compression spring 40 built into the valve casing 11.

Therefore, on the outer circumferential surface above the metering plunger 26, there is a lock ball 3.
Ball grooves 36, 37, and 38 into which balls 9 are inserted are formed at appropriate intervals.

Of course, the metering plunger 26 is
It is configured to be able to slide back and forth within its plunger bore 16 by operation within the cab of the vehicle, such as links and cables, hydraulic or pneumatic actuators (not shown), electromagnetic actuators, etc. It is driven via a valve (not shown) or the like.

Next, to explain the operation of the above-mentioned flow rate regulating valve 10, the metering plunger 26
is the normal state as shown in the figure, i.e.
When the internal combustion engine is operated and the oil pump is driven with the lock ball 39 dropped into the ball groove 37 and the metering orifice 27 slightly protruding into the inlet port 12, the oil - Pressure oil corresponding to the rotation of the pump is sent to the inlet port 12 and passes near the metering orifice 27.

The pressure oil is the metering orifice 27.
When passing near the metering orifice 27, the flow velocity increases and the static pressure decreases, causing the pressure oil sent to the tip side of the oil return control spool 17 and passing through the metering orifice 27. A pressure difference is created between the metering plunger 26 and the pressure oil sent to the communication passage 28 in the metering plunger 26.

Therefore, a portion of the pressure oil sent into the communication passage 28 with its flow rate and static pressure reduced is transferred to the back pressure chamber 31 of the valve chamber 15 via the pilot communication passage 32. Since there is a pressure difference between the pressure oil at the tip side of the oil return control spool 17 and the pressure oil in the back pressure chamber 31, the oil return control spool 17 return·
It is slid outward (to the right in the figure) against the spring 33, and the inlet port 12 and the bypass port 14 are brought into communication.

Thus, when the inlet port 12 and its bypass port 14 are connected, the pressure oil at the tip of the oil return control spool 17 is returned to the suction side of the oil pump.

In addition, the metering plunger 26 mentioned above
The pressure oil sent with a reduced flow rate into the communication passage 28 passes through the outlet side port 13 and is supplied to the power supply
The signal is sent to the reaction control valve side of the steering device, and the steering is placed in a state where it can be rotated with a predetermined operating force.

By operating inside the cab, the metering plunger 26 is slid toward the inlet port 12,
Drop the lock ball 39 into the ball groove 38,
When the metering orifice 27 is made to protrude further toward the inlet port 12, the flow velocity near the metering orifice 27 increases and the static pressure further decreases, causing the oil return control.
An even greater pressure difference is created between the pressure oil delivered to the distal end of the spool 17 and the pressure oil passed through the metering orifice 27 and into the communication passage 28 in the metering plunger 26.

Therefore, a portion of the pressure oil sent into the communication passage 28 with the flow rate further reduced and the static pressure further reduced is transferred via the pilot communication passage 32 to the back pressure of the valve chamber 15. Pressure oil is sent into the chamber 31 at the tip side of the oil return control spool 17 and its back pressure chamber 31
Since a larger pressure difference occurs between the pressure oil inside the oil return control
The spool 17 is further slid outward (rightward in the figure) against the return spring 33, and the pressure oil at the tip side of the oil return control spool 17 returns to the suction side of the oil pump. It becomes easier.

That is, the pressure oil sent into the communication passage 28 of the metering plunger 26 with its flow rate further reduced passes through the outlet port 13 and is fed to the reaction system of the power steering device.
The signal is sent to the control valve side, and the steering is placed in a state in which the steering can be rotated with an operating force greater than the above-mentioned predetermined operating force, that is, a so-called heavy steering state.

Also, by operating inside the cab, the metering plunger 26 is slid outward (leftward in the figure), the lock ball 39 is dropped into the ball groove 36, and the metering orifice 27
When retracted into the plunger bore 16, the flow velocity near the metering orifice 27 hardly changes, and the pressure oil sent to the tip side of the oil return control spool 17 and its metering The pressure of the pressure oil that passes through the orifice 27 and is sent to the communication passage 28 in the metering plunger 26 becomes almost equal.

Therefore, the pressure oil at the tip side of the oil return control spool 17 is connected to the valve chamber 15 via the pilot communication passage 32.
Since there is almost no pressure difference between the oil return control spool 17 and the pressure oil sent into the back pressure chamber 31 of the The inlet port 12 and the bypass port 14 are disconnected from each other.

When the communication between the inlet port 12 and the bypass port 14 is cut off, the pressure oil in the inlet port 12 is removed from the metering orifice 2.
7, is sent into the communication path 28, and passes through the outlet side port 13 without reducing the flow rate,
The signal is sent to the reaction control valve side of the power steering device, and the steering is placed in a state in which the steering can be rotated with an operating force smaller than the above-mentioned predetermined operating force, that is, the steering is in a light state.

In the tenth specific example of the flow rate regulating valve used in power steering according to the present invention described above, the pilot communication passage 32 is connected to the valve casing 11.
Although the inward portion of the plunger bore 16 and the back pressure chamber 31 of the valve chamber 15 are configured to communicate with each other, the outlet port 13 and the back pressure chamber 31 of the valve chamber 15 are
It may also be configured to communicate with.

According to this invention configured as described above, the weight of the steering wheel can be adjusted according to the driver's preference when driving with a high-speed rotation of an internal combustion engine, and the weight of the steering wheel can be adjusted according to the driver's preference, thereby reducing the driver's fatigue caused by steering operation. A flow rate regulating valve used for steering is obtained.

[Brief explanation of drawings]

The figure is a longitudinal sectional view showing a specific example of a flow rate regulating valve used in power steering according to the present invention. 10...Flow control valve used for power steering, 11...Valve casing, 12...
...Inlet side port, 13...Outlet side port, 14...
...Bypass port, 15...Valve chamber, 16...Plunger bore, 17...Oil return control spool, 26...
...Metering plunger, 27...Metering orifice, 28...Communication passage, 31...Back pressure chamber, 32...Pilot communication passage, 33...Return spring.

Claims (1)

[Claims] 1. An inlet port connected to the discharge side of the oil pump, an outlet port connected to the reaction control valve side of the power steering device, and a suction side port connected to the oil pump. a valve chamber formed in the valve casing with an inlet port communicating with the bypass port; and an inlet side thereof upstream of the valve chamber. A plunger formed in the valve casing connects the oil passage of the port to the outlet port.
a bore; an oil return control spool reciprocatingly slidably disposed in the valve chamber to regulate communication between the inlet port and the bypass port; and an inlet upstream of the valve chamber. A metering orifice opened to the oil passage of the side port and a communicating passage connecting the metering orifice to the outlet side port, disposed in the plunger bore, and slid into the plunger bore. A metering plunger that throttles and adjusts the oil passage of the inlet port that is upstream of the valve chamber, and a backrest formed in the valve chamber in cooperation with the oil return control spool. A flow rate adjustment valve used in power steering, which includes a pilot communication passage that supplies reaction control valve side pressure oil of the power steering device to a pressure chamber, and a return spring arranged in the back pressure chamber.