JPS5836766A - Flow control valve used for power steering - Google Patents

Abstract

PURPOSE:To improve the operational performance of steering by controlling a flow control valve so as to make steering heavier at a high speed travel and to reduce the steering at a low speed travel although the number of engine revolutions is increased in a sloping road and so on. CONSTITUTION:A diaphragm 16 and a valve chamber that contains an oil return control spool 17 are between inlet and outlet ports 12 and 13 and between the port 12 and a bypass port 14, respectively. A throttle rod 24 that adjusts the diaphragm 16 is mounted on the spool 17. Besides, a pilot communication path 27 that connects the port 13 and the chamber 15 is provided and a short circuit valve 31 that bypasses the diaphragm 16 is arranged on the way to the communication path 27. When a low speed gear is used even if an engine is revolved at high speed, the pressure of the chamber 15 is increased. As a result, the valve 31 is opened. A great amount of oil bypasses the diaphragm 16 and is sent to a power steering unit.

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 74-power steering often takes the form of a hooker mechanism installed in a manual steering mechanism, in which manual steering displacement is given as an input signal to the servo mechanism, and the output mechanism is It is configured to operate in accordance with the displacement of the steering wheel.

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 rotational speed of the oil pump due to the flow rate of the supplied pressure oil is controlled by the internal combustion engine. Since it is proportional to the rotation speed of the oil pump, a predetermined flow rate is ensured in the idling state, and when the internal combustion engine is running at high speed, unnecessary surplus flow is returned to the suction side of the oil pump and the steering The structure is such that the operating force required for rotation of the shaft can be maintained constant.

Furthermore, in recent years, in order to stabilize the steering when an automobile is traveling at high speed, there has been a tendency to use the flow control valve to slightly increase the weight of the steering.

However, the flow rate of pressurized oil controlled by such a flow rate regulating valve is set to obtain a predetermined flow rate depending on the rotational speed of the internal combustion engine, so when a car goes down a slope, it is difficult to use engine braking. or while using
When driving on an upward slope in a low gear with the engine revving, the internal combustion engine is rotating at high speed, making the steering operation difficult, especially when driving around curves that require light and fast steering operations. It was difficult to operate the steering wheel satisfactorily on many slopes.

The purpose of this invention is to make the steering operation light during normal driving, and to slightly increase the weight of the steering wheel when driving at high speeds, thereby stabilizing the steering.
Moreover, while going downhill while using the engine brake,
Alternatively, when driving uphill using a low gear while blowing the engine, the weight of the steering becomes lighter, improving the operability of the steering and enabling safe driving. The purpose of the present invention is to provide a flow rate regulating valve used in steering.

For this purpose, the flow regulating valve used in the power steering of this invention has two ports: one on the inlet side connected to the discharge side of the oil pump, and one on the outlet side connected to the reaction fist control pulp side of the power steering linkage device. a pulp casing with a vice port connected to the suction side of the oil pump and formed in the pulp casing to communicate the inlet side port with the pi/ips port; the pulp chamber, a constriction formed between the outlet port and the pulp chamber, and the communication between the inlet port and the bypass port.
An oil return control spool disposed so as to be reciprocally slidable in the chamber, and a two-pilot communication path connecting the downstream side of the throttle near the outlet port and the outside portion of the pulp chamber. , provided within the pulp casing upstream of the throttle,
The throttle also includes a short circuit pulp that connects the upstream and downstream sides of the throttle when the oil pressure on the upstream side exceeds a predetermined pressure.

Hereinafter, preferred specific examples of the flow rate regulating valve used in /4' power steering according to the present invention will be described with reference to the drawings.

The figure schematically shows a specific example 1O of a flow regulating valve used in the /IP power steering of the present invention.

Flow control valve 1 used in the 4-way steering
0 is installed independently in the hydraulic piping downstream of the oil pump (not shown), or
An inlet integrated into a pump and connected to the discharge side of the oil pump.
l An outlet port 13 connected to the reaction control pulp (not shown) side of the power steering device (not shown), and a bino or spor port 14 connected to the suction side of the oil pump. BAI with
between the casing 11 and the pulp chamber 15 formed in the pulp casing 11 so as to communicate the inlet port 12 with the bypass port 14; and the outlet port 13 and the pulp chamber 15; is arranged to be reciprocally slidable in the pulp chamber 15 so as to control the communication between the oriice 16 as a throttle formed in the pulp chamber 15 and the inlet side port 12 and the pipe gas port 14, and , an oil φ return control spool 17 equipped with a throttle rod 24 that changes the opening area of its orifice 16, and its outlet port) 1
3 and the outer part of the pulp chamber 15. In the Ilot communication passage 27 and its Norp casing 11,
It is provided upstream of the orifice 16, and when the pressure of the oil upstream of the orifice 16 exceeds a predetermined pressure, the pilot communication passage 27 is connected between the upstream and downstream sides of the orifice 16. It is composed of a sheet circuit pulp 31 that communicates with the sheet circuit pulp 31 through the sheet circuit pulp 31.

Of course, the flow regulating valve lO used in the nosower steering according to the invention shown in the figure is integrally incorporated in a suitable position of the oil pump, for example in the lower part. - The 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 side port 12 extending upward in a substantially vertical direction, and a power port 12.・Connected to the rear axle control valve side of the steering device, and connected to the outlet side port 13 extending laterally continuously from the inlet side/port 12, and the suction side of the oil pump. It is provided with a pinoyas port (14) extending upwardly in a substantially vertical direction in line with the inlet side port (12).

Of course, the outlet port 13 is connected to hydraulic piping (not shown).
is connected to the reaction control pulp side of the stirrer steering system.

The pulp casing 11 has an inlet port) 1
2 to its bypass, If-) 14,
A pulp chamber 15 is formed laterally.

Of course, the pulp chamber 15 has, at one end,
In order to connect the inlet side/-) 12 to the bypass φ port 14, a hole is machined laterally from one side of the pulp/rung 11, and the open end side is plugged (
(not shown).

Further, in the pulp casing 11, between the outlet port 13 and the pulp chamber 15,
An orifice 16 is formed in the pulp casing 11 to communicate the downstream side of the orifice 16 near the outlet side 13 with the outer part of the pulp chamber 15. A pilot communication path 27 is formed.

The pulp chamber 15 of the pulp casing 11 so configured has controlled communication between its inlet port 12 and its pipe/espace port 14, and from its inlet port 1.2. An oil return control spool 17 that changes the opening area of the oriice 16 is arranged to be able to reciprocate and slide so as to adjust the amount of oil supplied to the outlet port 13.

In other words, the oil return control school 17ij is formed into a substantially cylindrical shape with a relief pulp chamber 19 inside, and communicates with the relief pulp chamber 19 at the rear end and upper outer periphery. a spool body 18 in which a pressure oil inlet 20 and a pressure oil outlet 21 are respectively formed, and a throttle that is attached to the tip of the spool body 18 and is passed through the orifice 16 to change the opening area of the orifice 16. - in the rod 24 and its relief pulp chamber 19;
a ball poppet 22 that opens and closes the pressure oil inlet 20;
an oil return control configured as such: a return-sgeling ring 23 disposed within the relief-pulp chamber 19 so as to press the goal poppet 22 against the pressure oil inlet 20;・The spool 17 is made of pulp casing 11
If the pulp chamber 15 is disposed in the pulp chamber 15, a back pressure chamber 26 is formed in a portion closer to the outside of the pulp chamber 15 in cooperation with the sono-oil return e-control unit 17.

Of course, the back pressure chamber 26 is connected to the pilot communication passage 2 described above.
7 via the outlet port 1 downstream of the orifice 16
3 has been contacted.

Further, a return spring 25 is arranged in the back pressure chamber 26 to press the oil return control φ susol 17 inward.

Therefore, the oil return mechanism 17 is normally pressed inward by its return spring 25, and communication between its inlet port 12 and bypass port 14 is cut off. Of course, in such a state, the tip of the throttle rod 24 in the oil return control spool 17 is separated from the orifice 16 and is connected to the exit port 1.
Since the orifice 16 is located at three points, the opening area of the orifice 16 is maximized.

Furthermore, within the pulp casing 11, at gA+1 upstream of the orifice 16 and near the inner side of the pulp chamber 15, the pressure of the oil upstream of the orifice 16 is maintained, i.e., When the pressure of the oil supplied from the oil pump exceeds a predetermined pressure, a short pump 31 is provided to connect the downstream side 1 of the orifice 16 with the downstream side via the pilot communication passage 27. It is being

That is, in the pulp casing 11, a short circuit pulp chamber 28 is formed at a position closer to the inside of the pulp chamber 15, extending downward and perpendicular to the two pilot communication passages. Within the pulp chamber 28, the short circuit pulp 31 is slidably disposed back and forth.

The short circuit pulp 31 includes a pulp body 32 formed in a cylindrical shape and a pulp body 321p.
A ring groove 33 formed around the upper side surface, a communication path 34 connecting the ring groove 33 and the upper end of the pulp body 32, and a communication path 34 connecting the pulp body 32 in the short circuit pulp chahiba 28. It is composed of a return spring 35 for pushing upward.

Accordingly, the pulp body 32 is reciprocally slidably disposed within the short circuit pulp chamber 28, and the return spring 35 is disposed below the pulp body 32 to prevent such In the condition, the short circuit pulp chamber 2
A plug 36 is fitted below 8.

Of course, since the pulp body 32 is normally pushed upward by the return spring 35, the communication between the ring groove 33 of the pulp body 32 and the pilot communication passage 27 is cut off. However, in such a state, with the short circuit pulp 31 in the center, the holes and pilot communication passages 27 on both sides
In order to communicate the
A ring groove 29 is formed that connects the l+ pyro and cross passages 27.

In other words, even when the pulp body 32 is pushed upward by the return spring 35, there is no conflict between the outlet port 13 on the downstream side of the orifice 16 and the oil return control described above. The rear end of the susol 17 (with the back pressure chamber 26 of 111) is communicated with the mother pilot passage 27 and the ring groove 29.

Of course, the short circuit pulp 31 is pushed downward against the return spring 35 when the pressure of the oil supplied from the oil pump to the inlet port 12 exceeds a predetermined pressure. The ring groove 3
3 and its pilot communication passage 27, in other words, the upstream side and downstream side of its orifice 16 are configured to communicate with each other, but the above-mentioned predetermined pressure is
It is determined by the spring constant of the spring 35.

Therefore, the spring constant of the return spring 35 is:
When a car goes downhill, it uses both the engine and the brakes.
Alternatively, when the engine speed increases extremely and the pressure of the oil supplied from the oil pump to the inlet port 12 is high, such as when driving uphill using a low gear while revving the engine, Short circuit fist pulp 31 is pushed downward and its orifice 16
The spring constant is set to a predetermined value so that the upstream side and the downstream side of the spring can be connected.

Of course, in the case of normal high-speed running, since a high gear is used, the engine speed in that case is lower than the engine speed in the above-mentioned case, and therefore, the short circuit pulp 31 is maintained in an upwardly pushed state by its return and the sgelling 35.

Next, the operation of the flow rate regulating valve IO used in the A'war steering according to the present invention will be explained.

First, when the internal combustion engine is operated and the oil pump is driven, oil corresponding to the rotation of the oil pump is sent to the inlet port (12). Since the amount of oil sent to the orifice 12 is relatively small and the pressure drop at the orifice 16 is small, the oil return control spool 17 is located on the orifice 16 side (11!l on the left in the figure). From that entrance side port) 12 and pi i4 s., j
? -) 14 is cut off, and the oil passes through its orifice 16 and exits from the outlet port 13 to the reaction control system of the nine-wheel steering system.
Sent to the pulp side.

Therefore, the oil supplied from the oil pump is routed through the bypass port 14 to the reaction control pulp side of the oil pump without being returned to the suction side of the oil pump. The steering wheel is placed in a state where it can be rotated with force, that is, with a light operating force.

In addition, during high-speed operation, the amount of oil sent to the inlet port is large, and the pressure drop at Oriice 16 is large, so the oil return control stool 1
7 is slid to the outside (on the right side in the figure) against the return spring 25, and its inlet port 12 is connected to the bypass port 14, so that some of the oil is sucked into the oil pump. Moreover, as the oil return control stool 17 slides, its orifice 16 is throttled by the throttle rod 24, further increasing the pressure drop. Since the spool 17 is further slid to the right and the bypass port 14 is opened larger, the amount of oil returned to the suction side of the oil pump increases, and the output side, j? - The amount of oil sent from port 13 to the reaction control pulp side of the nowaer steering system is reduced.

Therefore, the steering wheel is placed in a state in which the steering wheel can be rotated with a larger operating force than the above-mentioned predetermined operating force, that is, a state in which the steering wheel is heavy and stable.

Furthermore, while going downhill while using the engine brake,
Alternatively, when traveling on an upward slope using a low gear while revving the engine, the engine speed is high as in the case of high speed operation, so the rear axle of the power steering device is The amount of oil sent to the control pulp side decreases, but when turning the wheel significantly in a curve, the oil pressure increases, so the short circuit pulp 31 mentioned above resists the return spring 35. The pulp is pressed downward, and the pulp is inserted into the ring groove 33 of the main body 32 and the short circuit.
The ring groove 219 of the pulp chamber 28 is aligned,
The upstream and downstream sides of the orifice 16 are communicated via a pilot passage 27.

Therefore, since the pressure difference between the upstream and downstream sides of the orifice 16 is reduced, the oil return control pulp returns to the left side. - Since the gate 14 is closed, the amount of oil sent to the reaction control pulp side of the power steering device increases, so even when the oil pump is rotating at high speed as mentioned above, the reaction control・Pulp
The flow rate of 11K of oil is large, and the steering wheel is placed in a state where it can be rotated with a light operating force.

According to this invention having the above structure, the steering operation is light during normal driving, the weight of the steering is slightly heavy during high speed driving, the steering is stable, and the steering is stable even when driving around curves. When driving downhill while using the engine brake, or when driving uphill with a curve using the engine and using a low gear, the weight of the steering becomes lighter and the operability of the steering becomes easier. A flow regulating valve used in power steering that enables improved and safe driving is obtained.

[Brief explanation of the drawing]

The figure is a schematic diagram showing a specific example of a flow rate regulating valve used in power steering according to the present invention. 10...Flow control valve used in power steering, ll...Pulp casing, 12...Inlet side port, 13...Outlet side yt? -), 1to...ノ4ino'? Port, ll... Pulp chamber, 16...
... Orifice, 17... Oil return control-spool, 24... Throttle mouth, )',
27...Nozoirot communication passage, 31...Short
circuit. Pulp 0

Claims (1)

[Claims] An inlet side port connected to the discharge side of the oil pump, an outlet side port connected to the reaction control pulp side of the Nokwar steering device, and an outlet side port connected to the suction side of the oil pump. a pulp casing having a bypass port formed in the pulp casing to connect the inlet port to the bypass port;
a chamber and a constriction formed between its outlet II+ port and its pulp chamber; An oil return control may also be located on the spool, with a pilot passage communicating between the downstream side of the throttle near the outlet port and the outer side of the pulp chamber, and the pulp casing. Inside, the throttle is also provided on the upstream side, and when the pressure of the oil on the upstream side of the throttle increases to a predetermined pressure or higher, a short circuit Φ connects the upstream side of the throttle and the lower fM@. Flow control valve used in power steering, including power steering.