JPH06321122A - Flow control valve - Google Patents

Abstract

(57) [Abstract] [Purpose] The drive torque cross of the hydraulic pump is reduced by eliminating the places where pressure loss occurs, and
(EN) Provided is a flow control valve capable of improving the movement performance of a plunger and thus the control performance. A housing 1 having a pump port P, a sleeve 3 provided in the housing 1, a plunger 5 movably arranged in the sleeve 3 and biased in one direction by an elastic member 7, and a plunger 5 The rod 9 arranged with its tip inserted in one end side of the
A variable orifice 11 formed between the rod 9 and the rod 9, and a pressure chamber 13 formed between the plunger 5 and the sleeve 3 and communicating with the pump port P side via a passage 15 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a flow control valve used in, for example, a power steering device for a vehicle, and more particularly to a reduction in drive torque of a hydraulic pump and an improvement in control performance.

[0002]

2. Description of the Related Art A flow control valve used in a power steering apparatus for a vehicle has, for example, a structure as shown in FIG. This is disclosed in Japanese Examined Patent Publication No. 57-79069. First, there is a housing 101, and this housing 101 is connected to a pump port P connected to a hydraulic pump (not shown) and a tank (not shown). A tank port T is formed. A sleeve 103 is screwed into the left side of the housing 101 in the figure. Also, the sleeve 10 is in the housing 101.
A spool 105 is accommodated on the right side of FIG. 3 so as to be movable in the left-right direction in the figure. An end plug 107 is mounted on the right side of the spool 105 in the figure, and a coil spring 109 is mounted between the spool 105 and the end plug 107. The spool 105 is this coil spring 1
09 is urged to the left side in the figure.

A plunger 11 is provided in the sleeve 103.
1 is housed so as to be movable in the left-right direction in the drawing. A member 113 is arranged in the sleeve 103 on the left side of the plunger 111 in the figure, and an end plug 115 is screwed on the left side thereof. Plunger 111
A coil spring 117 is mounted between the member 113 and the member 113, and the plunger 111 is urged to the right side in the drawing by the coil spring 117. Sleeve 1
A passage 103a is formed at 03 to connect the pump port P side and the plunger 111 side. Also, sleeve 1
A fixed orifice 118 is provided between the housing 101 and the outer edge portion at the right end of 03 in the figure. Also, the member 113
A control orifice 113a is formed in the end plug 115, and a hole 115a is also formed in the end plug 115.

In the above structure, the pressure oil discharged from the hydraulic pump is pump port P, fixed orifice 118,
Plunger 111, control orifice 11 for member 113
It is supplied to a power steering device (not shown) through the hole 3a of the end plug 115. At that time, the differential pressure before and after the fixed orifice 118 increases in proportion to the increase in the discharge amount of the hydraulic pump. On the other hand, the fixed orifice 118
The pressure on the primary side (pressure on the pump port P side) of the passage 10
It acts on the pressure chamber 119 between the plunger 111 and the sleeve 103 via 3a. By the action of the pressure,
The plunger 111 moves to the left side in the figure against the spring force of the coil spring 117. The movement of the plunger 111 gradually narrows the control orifice 113a, and as a result, the control flow rate (flow rate supplied to the power steering device) is controlled.

[0005]

The above-mentioned conventional structure has the following problems. First, a fixed orifice 118 is required to operate the plunger 111,
When such a fixed orifice 118 is provided, there is a problem that a pressure loss occurs there and drive torque loss of the hydraulic pump occurs. Also, passage 1
The pressure acting via 03a only acts on the pressure chamber 119, and the thrust force against the plunger 111 obtained thereby is relatively small. Therefore, there is a problem that the moving performance of the plunger 111, and thus the control performance, is easily affected by friction and the like.

The present invention has been made on the basis of such a point, and an object of the present invention is to reduce the drive torque cross of the hydraulic pump and to reduce the drive torque of the hydraulic pump by reducing the number of places where pressure loss occurs. The object of the present invention is to provide a flow rate control valve capable of improving the moving performance and thus the control performance.

[0007]

To achieve the above object, a flow control valve according to the present invention is provided with a housing having a pump port, a sleeve installed in the housing, and movably arranged in the sleeve. A plunger urged in one direction by an elastic member, a rod arranged with one end of the plunger inserted at its tip, a variable orifice formed between the plunger and the rod, the plunger and the sleeve. And a pressure chamber which is formed between the pressure chamber and the pump chamber and communicates with the pump port side via a passage.

[0008]

In other words, in the case of the present invention, the fixed orifice, which was conventionally provided outside the plunger, is eliminated, and instead, the variable orifice is constituted by the plunger and the rod. Both the differential pressure across the variable orifice and the pressure acting on the pressure chamber via the passage act as thrust for the plunger.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. First, there is a housing 1, and a pump port P connected to a hydraulic pump (not shown) is formed in the housing 1. A sleeve 3 is housed inside the housing 1, and an end plug 6 is screwed into the left side of the sleeve 3 in the figure. A plunger 5 is housed in the sleeve 3 so as to be movable in the left-right direction in the figure. The plunger 5 is biased to the right side in the figure by a coil spring 7 arranged on the left side in the figure.
A rod 9 is installed inside the coil spring 7, and the right end of the rod 9 is inserted into the plunger 5. And rod 9 and plunger 5
A variable orifice 11 is formed between and.

Further, a pressure chamber 13 is formed between the plunger 5 and the sleeve 3, and the sleeve 3 is provided with a damping orifice 15 as a passage for connecting the pressure chamber 13 and the pump port P side. Has been.
The rod 9 has a small diameter portion 9a and a large diameter portion 9b.

The operation will be described based on the above configuration. The pressure oil supplied from the hydraulic pump flows into the plunger 5 via the pump port P, flows into the hole 6a of the end plug 6 via the variable orifice 11, and is supplied from there to the power steering device side (not shown). It At that time, a differential pressure is generated before and after the variable orifice 11, and the differential pressure is generated by the plunger 5.
Against the spring force of the coil spring 7 and acts as a thrust to move the coil spring 7 to the left side in the drawing. The thrust force for moving the plunger 5 in the same direction is not only the above-mentioned differential pressure but also the pressure acting in the pressure chamber 13 via the damping orifice 15.

When the plunger 5 moves to the left side in the figure, the plunger 5 moves to the large diameter portion of the rod 9,
As a result, the opening area of the variable orifice 11 is reduced and the flow rate of the pressure oil supplied to the power steering device side is controlled.

According to this embodiment, the following effects can be obtained. First, the pressure loss is reduced as compared to the conventional configuration, which can reduce the drive torque loss of the hydraulic pump. This is because the fixed orifice, which has been conventionally arranged outside the plunger, which causes pressure loss, is eliminated. still,
The variable orifice 11 functions as a conventional fixed orifice. In addition to the above-mentioned differential pressure, the thrust acting on the plunger 5 is a pressure acting in the pressure chamber 13 via the damping orifice 15, and thus the thrust becomes larger than the conventional thrust. Therefore, unlike the conventional case, the moving performance of the plunger 5 and thus the control performance are not affected by the influence of friction.

Next, a second embodiment will be described with reference to FIG. In the case of this embodiment, the taper portion 9c is provided between the small diameter portion 9a and the large diameter portion 9b of the rod 9 in the first embodiment.
Is provided. By providing such a tapered portion 9c, finer flow rate control becomes possible.

Next, a third embodiment will be described with reference to FIGS. A V-shaped notch portion 21 is provided at the end of the variable orifice 15 on the plunger 5 side, and in this case as well, finer flow rate control is possible, as in the case of the second embodiment. It is a thing.

[0016]

As described above in detail, according to the flow control valve of the present invention, the fixed orifice, which is conventionally provided outside the plunger, is eliminated, and instead the variable orifice is constituted by the plunger and the rod. Since both the pressure difference across the orifice and the pressure acting on the pressure chamber via the passage act as thrust for the plunger, pressure loss is reduced and drive torque of the hydraulic pump can be reduced. Further, since the thrust on the plunger is increased, it is less likely to be affected by friction, and thus the control performance can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a flow rate control valve showing the first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a flow rate control valve showing the second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention and is a partial cross-sectional view of a flow control valve.

FIG. 4 is a diagram showing a third embodiment of the present invention and an enlarged view of a part of FIG. 3;

FIG. 5 is a cross-sectional view of a flow rate control valve showing a conventional example.

[Explanation of symbols]

 1 Housing 3 Sleeve 5 Plunger 7 Coil Spring (Elastic Member) 9 Rod 11 Variable Orifice 13 Pressure Chamber 15 Damping Orifice (Passage)

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[Procedure amendment]

[Submission date] July 27, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art A flow control valve used in a power steering apparatus for a vehicle has, for example, a structure as shown in FIG. This is disclosed in Japanese Utility Model Laid- Open No. 57-79069. First, there is a housing 101, and this housing 101 is connected to a pump port P connected to a hydraulic pump (not shown) and a tank (not shown). A tank port T is formed. A sleeve 103 is screwed into the left side of the housing 101 in the figure. Also, the sleeve 10 is in the housing 101.
A spool 105 is accommodated on the right side of FIG. 3 so as to be movable in the left-right direction in the figure. An end plug 107 is mounted on the right side of the spool 105 in the figure, and a coil spring 109 is mounted between the spool 105 and the end plug 107. Spool 105 is this coil spring 1
09 is urged to the left side in the figure.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

In the above structure, the pressure oil discharged from the hydraulic pump is pump port P, fixed orifice 118,
Plunger 111, control orifice 11 for member 113
It is supplied to a power steering device (not shown) through the hole 3a of the end plug 115. At that time, the differential pressure before and after the fixed orifice 118 increases in proportion to the increase in the discharge amount of the hydraulic pump. On the other hand, the fixed orifice 118
Pressure on the temporary side (pressure on the pump port P side) of passage 10
It acts on the pressure chamber 119 between the plunger 111 and the sleeve 103 via 3a. By the action of the pressure,
The plunger 111 moves to the left side in the figure against the spring force of the coil spring 117. The movement of the plunger 111 gradually narrows the control orifice 113a to the end face closed state, and as a result, the control flow rate (flow rate supplied to the power steering device) is controlled.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

[0005]

The above-mentioned conventional structure has the following problems. First, a fixed orifice 118 is required to operate the plunger 111,
When such a fixed orifice 118 is provided, there is a problem that a pressure loss occurs there and drive torque loss of the hydraulic pump occurs. Also, passage 1
The pressure acting via 03a only acts on the pressure chamber 119, and the thrust force against the plunger 111 obtained thereby is relatively small. Therefore, there is a problem that the moving performance of the plunger 111, and thus the control performance, is easily affected by friction and the like. In addition, the movable orifice for the control orifice 113a is movable.
When the end face of the ranger 111 is closed, a slight plunge
The gap between the end faces that is controlled by the movement of the arm 111 is large.
Change and the change in the orifice characteristics becomes large.
It becomes unstable control.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

[Means for Solving the Problems] To achieve the above object
A flow control valve according to the present invention includes a housing and a housing.
Sleeve inside the sleeve and slide inside the sleeve.
Oil passage that is movably accommodated and penetrates along the axis
Formed on the housing and the plunger
Pump port that directly communicates with one end of the oil passage
And the oil passage is provided at the opposite end of the
The spring urging the
Formed between the leave and introduces pump port pressure
Pressure chamber and the large diameter part that is fixed to the housing side
And a rod having a small diameter portion, the small diameter portion side of this rod
Insert the tip by exposing it in the oil passage of the plunger.
A variable orifice is formed at the entrance, and this variable orifice
Action on the pressure chamber and the end face of the plunger by the hydraulic pressure before
Combined force, spring force of spring and variable orifice
Depending on the difference between the resultant hydraulic force and the resultant force, the plunger
It is moved so that the opening area of the variable orifice changes.
It has a feature in the point.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. First, there is a housing 1, and a pump port P connected to a hydraulic pump (not shown) is formed in the housing 1. A sleeve 3 is housed inside the housing 1, and an end plug 6 is screwed into the left side of the sleeve 3 in the figure. A plunger 5 is housed in the sleeve 3 so as to be movable in the left-right direction in the figure. The plunger 5 is biased to the right side in the figure by a coil spring 7 arranged on the left side in the figure.
Also, fixed to the end plug 6 inside the coil spring 7.
The rod 9 is installed, and the right end of the rod 9 is inserted into the plunger 5. A variable orifice 11 is formed between the rod 9 and the plunger 5. In addition, in the device of this embodiment
Jing shall consist of housing 1 and end plug 6.
It

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

Further, a pressure chamber 13 is formed between the plunger 5 and the sleeve 3, and the sleeve 3 is provided with a damping orifice 15 as a passage for connecting the pressure chamber 13 and the pump port P side. Has been.
The rod 9 has a small diameter portion 9a and a large diameter portion 9b. Assemble the spool 16 to the right side of the plunger 5 in the figure.
The spring chamber 18 is made to face while being inserted. This
While the spring 17 is housed in the pulling chamber 18,
This spring 17 causes the spool 16 to move leftward in the drawing.
Is urged by. Further, the spring chamber 18 has an oil passage.
The passage 22 guides pressure oil on the downstream side of the variable orifice 11.
Be done. Thus, the differential pressure across the spool 16 is variable
It becomes equal to the differential pressure before and after Liffith 11. This spool 1
Inside 6, a relief valve is provided. That is, sp
The pressure oil in the ring chamber 18 passes through the filter 19 and
The pressure of the spring 20
When the pressure becomes larger than the pressure set by 21, the ball 20
Press to open the pressure oil from the tank port T (not shown)
Put it back in the tank.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

When the plunger 5 moves to the left side in the figure, the plunger 5 moves to the large diameter portion of the rod 9,
As a result, the opening area of the variable orifice 11 is reduced and the flow rate of the pressure oil supplied to the power steering device side is controlled. The variable orifice
The differential pressure around 11 is determined by the opening of the spool 16.
It When the pump speed is low, the oil flow rate is low and
Therefore, the differential pressure before and after the variable orifice 11 is small. Also, pon
As the engine speed increases, the oil flow rate increases
Therefore, the differential pressure before and after the variable orifice 11 becomes large. the above
The differential pressure across the spool 16 is
Since it is equal to the differential pressure around 11, so if the differential pressure becomes large,
The pool 16 resists the spring force of the spring 17 and moves to the right in the figure.
Move toward. In this way, the spool 16
When moving in a row, the pump port P becomes the tank port T.
In communication, oil is returned to the tank. And the pump port
The product of the pressure on the P side and the pressure receiving area of the spool is the spring 1
7, the spring force, the pressure in the spring chamber 18 and the spool
At the position where it becomes equal to the resultant force of the products of the pressure receiving areas, the spool 16
Balance. As described above, the movement amount of the spool 16
According to the pump speed
The pressure difference before and after the valve 11 changes and is not shown
It supplies the necessary pressure oil to the power steering device.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

According to this embodiment, the following effects can be obtained. First, the pressure loss is reduced as compared to the conventional configuration, which can reduce the drive torque loss of the hydraulic pump. This is because the fixed orifice, which has been conventionally arranged outside the plunger, which causes pressure loss, is eliminated. still,
The variable orifice 11 functions as a conventional fixed orifice. In addition to the above-mentioned differential pressure, the thrust acting on the plunger 5 is a pressure acting in the pressure chamber 13 via the damping orifice 15, and thus the thrust becomes larger than the conventional thrust. Therefore, as in the past
The movement performance of the plunger 5 is impaired due to the influence of friction.
And the cylindrical variable orifice,
The change in the orifice effect due to the axial displacement of the Langer 5
It can be stabilized and control performance can be improved.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016]

As described above in detail, according to the flow control valve of the present invention, the fixed orifice which is conventionally provided outside the plunger is eliminated, and instead, the variable orifice is constituted by the plunger and the rod. Since both the pressure difference across the orifice and the pressure acting on the pressure chamber via the passage act as thrust for the plunger, pressure loss is reduced and drive torque of the hydraulic pump can be reduced. In addition, since the thrust force on the plunger is increased, it is less affected by friction, and because of the cylindrical variable orifice,
Small change in orifice due to minute vibration of runner
Therefore, compared with the conventional end face closed type,
It can be stably maintained and control performance can be improved.
It

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 12]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 13]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 14]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (1)

[Claims] 1. A housing provided with a pump port, a sleeve mounted in the housing, a plunger movably arranged in the sleeve and urged in one direction by an elastic member, and one end side of the plunger. A rod arranged with its tip inserted into the pressure chamber, a variable orifice formed between the plunger and the rod, and a pressure chamber formed between the plunger and the sleeve and communicating with the pump port side through a passage. And a flow control valve.