JP2685171B2 - Displacement control device for variable displacement pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]   The present invention relates to a displacement control device for a variable displacement pump, and an example
For example, it is effective for use in the power steering system of automobiles.
You. Power steering device requires large amount of working fluid
When increasing the discharge amount from the pump,
If the steering system requires only a small amount of working fluid,
In that case, the discharge amount from the pump is reduced. [Conventional technology]   Conventionally, various types of capacity control devices have been proposed.
Is being planned. Especially the power consumption of the drive source that drives the pump
Is determined by the product of the pump discharge pressure and discharge amount
Therefore, the product is controlled to be constant and the pump is efficiently driven.
Devices have been proposed. For example, JP-A-58-110881
There is a device described in the publication.   However, with this type, the aperture used for capacity control
Supplies the working fluid from the pump to the driven actuator
It is provided separately from the fluid passage. That is, capacity system
A service throttle is provided on a signal passage separate from the fluid passage.
Variable control of pump capacity based on flow rate in signal passage
I control Therefore, the signal passage always has a signal operation.
I had to run the fluid. Especially for this signal
The working fluid has a flow rate proportional to the working fluid flowing through the fluid passage.
Required to flow a large amount of working fluid into the fluid passage.
When necessary, a large amount of working fluid for signals is also required.
Is required. Therefore, in this conventional device, unnecessary energy is consumed.
There was a problem of consuming ghee. at the same time,
In addition to the fluid passage, a signal passage must be piped,
There is also the problem that the configuration of the entire device becomes complicated.
Was.   Further, in JP-A-58-206893, the fluid passage is
A variable throttle that is arranged in the middle to change the cross-sectional area of the fluid passage,
Equipped with pressure detection means to detect the pressure before and after this variable throttle
The variable capacitance means can be operated based on the signal from the pressure detection means.
Pump discharge so that the differential pressure before and after the variable throttle is almost constant
The capacity is varied and the variable throttle is based on the pressure upstream of the variable throttle.
The variable control is shown. But this
In the case of such a configuration, the variable throttle will be affected by the pulsation of the pump discharge pressure.
Because the pressure pulsation is relatively large on the upstream side, this pulsation causes
The opening area of the pressure type variable throttle valve vibrates slightly,
Pump capacity control may become unstable (for example, hunting may occur).
There is a risk that. [Problems to be solved by the invention]   The present invention has been devised in view of the above points, and has a special
The actual flow through a fluid path without the need for a signal path
The discharge capacity of the pump based on the working fluid volume of the
With the goal.   At the same time, in the present invention, it is guided to the driven actuator.
Control the amount of working fluid to maintain good pump efficiency.
The porpose is to do.   That is, in the present invention, the discharge pressure and the discharge amount of the pump
While keeping the product constant, change the pump discharge capacity to
Controlling the amount of working fluid introduced to a dynamic actuator
With the goal.   In addition, the present invention is designed so that it can be supplied to a driven actuator.
Pumps the amount of dynamic fluid with variable pump capacity and variable throttle
After making the control with the best efficiency,
It is further supplied to the driven actuator by the auxiliary variable diaphragm.
The purpose is to be able to adjust the amount of working fluid.   Furthermore, the present invention provides a state in which the discharge capacity of the pump is minimized.
Even if it is, the driven actuator can be controlled well.
The purpose is to do so. [Means for solving the problem and its operation]   In the present invention, the operation supplied to the driven actuator
As shown in the equation (1), the fluid quantity Q is determined by opening the fluid passage.
By the product of the mouth area S and the pressure difference ΔP before and after throttling in the fluid passage
In view of the fact that Q = S ・ ΔP^{1 ] 2}            …………………… (1) By controlling the discharge capacity of the pump,
Fluid that is kept constant and is guided to the driven actuator
Employs a configuration in which the opening area S is changed based on the pressure.
You.   That is, the present invention is a pump having variable capacity means,
Driven the fluid discharged from this pump
Fluid passage leading to the
Pressure detection means for detecting the differential pressure before and after this variable throttle
And Based on the signal from the pressure detection means, the pump
The capacity is changed so that the front-rear differential pressure ΔP becomes constant.
At the same time, the working fluid supplied to the driven actuator
Based on the pressure, that is, the working fluid pressure downstream of the variable throttle,
The variable throttle changes the opening area of the working fluid.   In the second aspect of the present invention, the auxiliary variable throttle is provided in the fluid passage.
By arranging it, it is supplied to the driven actuator.
The working fluid amount Q is controlled separately. So
Therefore, in the second invention, it is not constant based on the configuration of the first invention.
Adjusts and controls the amount of working fluid Q that has been obtained based on other auxiliary signals.
You can   In the third aspect of the present invention, the operation of the variable throttle in the fluid passage is performed.
An escape groove is provided to allow a small amount of fluid to escape. This is
It is based on the reason.   The pump determines its discharge capacity based on the signal from the pressure detection means.
Since the aperture area of the variable diaphragm is small,
In this state, the pump discharge capacity is also small. Ma
Also, the fluid discharged from the pump is
It is known that the pressure pulsates with it. And
Especially when the pump is operated with a small capacity, this discharge pressure
Pulsations will have a large impact. That is, discharge
The relative effect of pressure pulsations increases, and as a result
A relatively large pressure pulsation is applied to the actuator as well.
And the good operation of the driven actuator is impaired.
You.   Therefore, in the third aspect of the invention, even if the variable throttle restricts the fluid passage.
Even if it is closed or close to closing,
The body should be pumped out so that
The effect of pump discharge pulsation when the capacity is small is mitigated. 〔Example〕   A first embodiment of the present invention will be described below with reference to the drawings.   FIG. 1 shows the schematic configuration of the first embodiment, and in FIG.
0 is the pump, 200 is the working flow discharged from this pump 100
A fluid passage for guiding the body to the driven actuator 300.
In this embodiment, as a driven actuator,
A power cylinder of the power steering device is used.
301 is a switching of the working fluid introduced to this power cylinder
It is a switching valve that operates.   400 is a variable throttle provided in the middle of the fluid passage 200,
-Pressure of fluid supplied to cylinder 300, that is, variable
It is controlled based on the pressure Pi downstream of the throttle 400. 401 is operating pressure
This is a pressure guiding passage for guiding the force Pi to the variable throttle 400.   500 is a variable capacity means for changing the discharge capacity of the pump 100.
In this example, the first and second drive pistons 501 and 502 are provided.
You. This pressure varying means 500 is the hydraulic pressure from the pressure detecting means 600.
It is driven based on the signal. That is, from the pressure detecting means
High pressure is introduced into the first drive piston 501 and low pressure is in the second drive
When it is introduced into the moving piston 502, the variable capacity means 500 becomes a pump.
Increase the discharge capacity of 100. On the contrary, from the pressure detection means
A low pressure is introduced into the first drive piston 501 and a high pressure in the second drive piston 501.
When introduced into the moving piston 502, the variable capacity means 500
Reduce the discharge capacity of 100.   The pressure detecting means includes first and second signal pressure passages 601 and 602.
The pressure around the variable throttle 400 is introduced via this. And
The difference in pressure introduced from these signal pressure passages 601 and 602,
That is, the differential pressure around the variable throttle 400 is detected. Based on this differential pressure
As described above, the pressure supplied to the variable capacity means is controlled.
Control.   FIG. 2 shows the configuration shown in FIG. 1 in a more specific manner.
It is. The pump 100 is a
The driving force is received via the electromagnetic clutch 701 to rotate. Ma
The pump 100 sucks the working fluid from the reservoir 750 into the suction passage 75.
Inhale through 1.   The variable throttle 400 has a sliding piston 404.
The sliding piston 404 is perpendicular to the fluid passage 200 in the middle of the fluid passage 200.
It is slidably arranged in the cylinder part 403 formed in the direction.
Have been. A passage portion 405 is formed in the sliding piston 404.
Of the passage portion 405 facing the inner fluid passage 200.
The fluid passage is changed depending on the area. That is, the passage part
When there are many 405 facing the fluid passage 200, the variable throttle
The iris 400 has a small aperture. On the other hand, the passage 405 flows only a little.
When the variable diaphragm 400 does not face the body passage 200,
The amount of aperture is large.   The sliding piston 404 is located after the cylinder 403 and the piston 404.
The pressure of the working fluid introduced into the pressure chamber 406 formed by the end
Force and the spring 407 installed on the other end of the piston 404.
It slides left and right in the figure due to a constant force. The pressure chamber 406 is
The pressure Pi downstream of the variable throttle 400 is introduced via the pressure passage 401.
You. Therefore, the pressure Pi should not exceed the setting force of the spring 407.
Then, the piston 404 moves to the right in the figure based on the pressure.
However, the opening area of the fluid passage is reduced accordingly.   The pressure detection means 600 includes the pressure generated in the housing.
The chamber 610 and a switching device slidably arranged in this pressure chamber
E valve part 611, pressure guide hole 612 for introducing high pressure to the pressure chamber, pressure chamber
Pressure relief holes 613 and 614 to release pressure from 610
First pressure passage 620 in communication with the first drive piston of the metering means
And a second pressure passage 621 that communicates with the second drive piston 502.
Is provided.   Then, in the pressure chamber 610, the first pressure chamber 630 at the right end in the drawing is
Is the fluid pressure downstream of the variable throttle 400 via the first signal passage 601.
Force Pi is introduced. Also, of the pressure chamber 610, the
Variable to the second pressure chamber 631 via the second signal pressure passage 602
The pressure Pd upstream of the throttle 400 is introduced. The first pressure chamber 630
Inside, a spring 640 having a predetermined set pressure is arranged.
ing. Therefore, it is introduced through the signal paths 601 and 602.
The differential pressure ΔP before and after the variable throttle 400 and the set force of the spring 640
Causes the switching valve unit 611 to slide in the pressure chamber 610 to the left and right in the figure.
I do.   The switching valve unit 611 includes the first and second interlocking units 650 and 651.
Is formed, and by the first and second communication parts 650 and 651
Switching between the pressure guide hole 612 and the first and second pressure passages 620 and 621
And the exhaust pressure holes 613 and 614 and the first and second pressure passages 620 and 621.
And are switched.   4 and 5 show one embodiment of the pump 100.
In the figure, 101 is an automobile engine 70 via an electromagnetic clutch 701.
Shaft that rotates by the rotational force of 0, 102 is this shaft
A bearing that rotatably supports the
Supported. 104 is an O-ring 105 on the main housing 900
This pintle is oil-tightly coupled via
Cylinder between housing 900, pintle 104 and housing 103
The working space 106 is formed. 107 is located in the working space
The inner ring of the main housing 900
Outer race 108 and inner race 109 retained
And a large number of balls arranged between these races 108, 109
It consists of 110.   The pintle 104 has a central protrusion that discharges to the working space 106 side.
A portion 111 is provided, and the central protrusion 111 has a bush.
A rotor 113 is rotatably supported via a window 112.
The rotor 113 rotates integrally with the shaft 101. Rotor
Six cylinders 114 are radially formed in 113,
A piston 115 is slidably arranged in this cylinder 114.
Have been. 116 is a spur that pushes the piston 115 outward.
The tip of the piston 115 always contacts the inner race 109.
In contact.   The pintle 104 has a suction passage 120 and a discharge passage 121.
Each of the central projections 111 has a rotor 113 side.
It is open to. That is, the suction passage 120 has the suction communication groove 1
22 Open the rotor 113 at the site corresponding to the intake stroke.
On the other hand, the discharge passage 121 is low in the discharge communication groove 123.
The opening of the nozzle 113 corresponds to the discharge stroke.   The main housing 900 includes a first drive piston 501 and a first drive piston 501.
2nd drive piston 502 1st and 2nd which holds slidably
Holding portions 150 and 151 are formed. Both holding parts 150, 1
Inside the 51, springs 152 and 153 are arranged, respectively.
Both springs 152 and 153 engage the drive pistons 501 and 502.
Press to the side of the water race 108.   The first pressure passage 620 and the second pressure passage 621 described above are
Each is formed in the main housing 900, and
The tips communicate with the first and second holders 150 and 151. Also,
Both holding parts 150 and 151 are opened ends by blind screws (not shown).
Closed to form a closed space inside the main housing 900.
ing.   The pressure detecting means 600 is formed inside the main housing 900.
ing. That is, the pressure chamber 610 is provided in the main housing 900.
Is formed, and the switching valve 611 slides in this pressure chamber 610.
It is located there. The pressure chamber 610 is attached by the blind screw 170.
Closed to form a closed space. In addition, the first
Not only the second pressure passages 620 and 621 but also the pressure guiding passage 612 and
2nd signal passage 602 which leads signal pressure to 2 pressure chamber 631 is also main
It is formed in the housing 900. Exhaust pressure passage 613 and 61
4 is also formed inside the main housing 900,
The passage communicates with the working space 106.   In addition, at the left end of the switching valve portion 611 in the figure, the one shown in FIG.
The projection 645 is formed so that
Fits into the receiving portion 646 formed on the main housing 900
Is formed. Tip of protrusion 645 is tapered
Formed, so that the protrusion 645 fits into the receiving portion 646.
The working fluid in the receiving part 646
Then, it flows out to the first pressure chamber 630 side. At this outflow, the working flow
Body flow has a narrow gap between the taper and the receiver 646.
And the flow of the working fluid is blocked. Therefore,
It is said that the switching valve portion 611 suddenly fits into the receiving portion 646.
The situation is prevented.   In addition, in the example shown in FIG. 6, the tapered portion is the tip of the protrusion 645.
However, as shown in FIG. 7, a tape is formed on the receiving portion 646 side.
You may form a super part. Furthermore, as shown in FIG.
A ring 648 having a large number of pores 647 is arranged on the protrusion 645.
May be. In this case, as shown in FIG.
The fluid in 6 flows to the first pressure chamber 630 side through the pores 647.
At this time, it is cut off by the diaphragm effect of the pores 647.
The abrupt movement of the transfer valve unit 611 is prevented. The ninth
In the illustrated embodiment, the spring 640 is located within the first pressure chamber 630.
Instead, it is disposed in the receiving portion 646.   A variable diaphragm 400 is arranged in the pintle 104. You
That is, as shown in FIG. 4, the discharge passage in the pintle 104 is
The passage 121 simultaneously forms the fluid passage 200, and thus this discharge
The variable throttle 400 is arranged in the exit passage 121. Therefore, the figure
Although not shown, the pressure passage 401 for guiding the pressure Pi downstream of the variable throttle 400
Is also formed in the pintle 104.   The opening area of the variable throttle 400 is equal to the pressure Pi downstream of the throttle.
Accordingly, it changes as shown in FIG. That is, the pressure Pi
If the load is smaller than the set load Po of the pulling 407,
404 does not displace, so the passageway 405 maintains a maximum open area.
I have (between AB in the figure). Pressure Pi is larger than set load Po
, The piston 404 moves to the right in FIG.
The opening area of the passage 405 decreases with the movement of
while).   Depending on the diaphragm amount of this variable diaphragm 400, the operation of the diaphragm 400 downstream
The dynamic fluid flow rate also changes as shown in FIG. The tenth
The discharge amount increases between KL in the figure, but this is due to the variable diaphragm 400
It is not based on the change in the opening area of
This is based on the change in the ejection amount at the time of rising. Sand
When the discharge pressure is low, the first drive piston 501 and
And the pressure of the working fluid applied to the second drive piston 502
The force is smaller than the load applied by the springs 152 and 153.
You. This is due to the balance of the loads on the springs 152 and 153.
The position of the rotary ring 107 to the side of the pump 100 where the capacity is small.
Because it is located. In addition, setting of spring 152
The load is larger than that of the spring 153. The result
The amount of fruit discharged is reduced.   Here, the characteristics of Fig. 3 and Fig. 10 are similar.
This is due to the following reasons.   As described above, the flow of the working fluid flowing through the variable throttle 400.
The quantity Q is obtained from the opening area S and the differential pressure ΔP across the
You.   Cd is the flow coefficient and ρ is the working fluid density
Therefore, it is considered to be almost constant. Also, the differential pressure across the pump
The discharge capacity of 100 is variable and controlled so that it is always constant.
ing. Therefore, according to the equation (2), the flow rate Q is the variable throttle 400
The mouth area S indicates that it is almost uniquely determined.   And in this example, the operating efficiency of the pump 100 is optimized.
Therefore, the product of the discharge flow rate (flow rate Q) and the discharge pressure P (P ×
The shape of the passage portion 405 of the variable throttle 400 so that Q) becomes constant.
Is stipulated.   FIG. 11 is a graph showing the shape of the passage portion 405,
The horizontal axis represents the moving direction of the piston 404. Therefore,
When the shape of the passage portion 405 is expressed as Y = f (x),
The opening area of the passage portion 405 is obtained by the following equation.  This equation (3) and the above condition, that is, P × Q is constant
The shape of the passage portion 405 is determined by the above.   As shown in FIG. 11, the tip of the passage 405 is
It is not the shape obtained from the formula but the arcuate part 480
You. This is the passage part 4 when the piston 404 has moved the maximum amount.
This is to sharply reduce the opening area of 05. In Fig. 3
The space between CDs and the space between NOs in FIG. 10 correspond to this arc-shaped portion 480.
You.   In addition, the shape shown in FIG. 11 minimizes the power consumption of the pump 100.
It is the most desirable for the above, but other shapes are also acceptable
Of course. Figure 12 shows the curve shown in Figure 11 as a straight line.
It is an approximation. As a result, the shape shown in FIG.
The molding of the road portion 405 becomes easy. Incidentally, FIG. 3 and FIG.
The characteristic shown by the middle broken line b is the passage part of the shape shown in FIG.
This is an example using 405.   Further, as shown in FIG. 13, the passage portion 405 is formed into one straight line.
May be molded.   On the other hand, the tip of the passage portion 405 has an arc shape as shown in FIG.
Even if it is not part 480, the shape as shown in FIGS. 14 and 15
It may be. In this case, the discharge amount characteristics as shown in Fig. 16
Is obtained. The solid line 1 in FIG. 16 is shown in FIGS. 11 to 13.
The characteristics of the arc-shaped portion 480, the solid line m shows the tip portion 481 in FIG.
In the example shown and the solid line n, the tip portion 481 is shown in FIG.
It is an example of a state.   Next, the operation of the device configured as described above will be described. Engine
Shaft 101 inside housing 103
When rotated, the rotor 113 also rotates in synchronization with the shaft 101.
You. At this time, the rotor 113 is surrounded by the rotating ring 107.
The center line of the rotating ring 107 and the center line of the rotor 113 are eccentric.
As the rotor 113 rotates, the piston 115
Reciprocates in the cylinder 114. This piston 115
Is the amount of eccentricity between the rotor 113 and the rotating ring 107.
It is twice as much.   As the piston 115 reciprocates, the piston 115 and the cylinder
The volume of the pressure chamber space 190 surrounded by the da 114 increases and decreases.
You. In the suction stroke where the pressure chamber 190 expands in volume, the suction passage 120
The working fluid sucked from the pressure is applied through the suction communication groove 122.
Introduced into room 190. Then, the volume of the pressure chamber 190 decreases.
In the discharge stroke, the working fluid in the pressure chamber 190 is discharged through the discharge communication groove 1
It is discharged to the discharge passage 121 via 23.   As described above, the piston 115 is connected to the rotary ring 107 and the low ring.
The reciprocating stroke is variable according to the amount of eccentricity with the motor 113.
In this example, the first and second drive pistons are provided on both ends of the rotary ring 107.
Tons 501, 502 are arranged, and both pistons 501, 5
As the 02 moves, the rotating ring 107 also moves to the left and right in FIG.
Displace. Rotation ring 107 moved to the right in the figure
In the state shown in Fig. 5, the amount of eccentricity is the largest, and
Therefore, the volume variation of the pressure chamber 190 is also maximum. Therefore, this
In the state, the discharge amount from the pump 100 becomes maximum. vice versa,
When the rotary ring 107 moves to the left in FIG.
The amount of eccentricity decreases with the movement, and therefore the discharge amount of pump 100
Decrease.   In this example, the pressure detecting means 600 and the variable capacitance means 5
With 00, the discharge amount of the pump 100 is the differential pressure across the variable throttle 400.
Is controlled so that it is always constant. That is, variable aperture
The pressure Pi downstream of 400 is detected via the first signal pressure passage 601.
The discharge means is introduced into the first pressure chamber 630, and the upstream of the variable throttle 400
The pressure Pd is applied to the inside of the second pressure chamber 631 via the second signal pressure passage 602.
Will be introduced. The first pressure chamber 630 and the second pressure chamber 631 face each other.
Therefore, the differential pressure (Pd-Pi) is applied to the switching valve 611.
available. Then, the switching valve unit 611 is arranged to
It moves by the set force of the ring 640.   If the differential pressure is less than the set force of spring 640,
The switching valve is pressed to the right in Fig. 5 by the ring 640.
Is done. Therefore, the operation of the pressure discharged from the pressure chamber 190
The fluid flows from the pressure guiding hole 612 to the first pressure passage 62 via the passage portion 651.
Supplied to 0, which is high on the back of the first drive piston
Apply pressure. At the same time, the back pressure of the second drive piston 502
Flows from the second pressure passage 621 to the communication portion 650, and
Is returned to the space 106 side of the pump 100. Therefore, the rotating phosphorus
Gu 107 increases its eccentricity by the first drive piston
Pushed in the direction. Therefore, when the differential pressure is small, the pump
The discharge amount of the pump 100 is increased.   As the pump displacement increases, the result is a variable throttle 400
The differential pressure before and after becomes large. Differential pressure set with spring 640
When the pressure exceeds the pressure, the switching valve unit 611 resists the spring 640.
Move to the left in FIG. Then, the discharge of pump 100
The output pressure is from the pressure guide hole 612 via the communication part 650 to the second pressure passage.
Flow to the back of the second drive piston to direct high pressure. Also,
The back pressure of the first drive piston 501 is the first pressure passage 620, the communicating portion.
Escape to the space 106 side of pump 100 through 651 and pressure relief hole 613.
Is done. Therefore, the rotating ring 107 is
Is pressed in the direction in which the amount of eccentricity decreases. Follow
If the differential pressure across the variable throttle 400 increases, the pump 100
Reduces the discharge rate.   By repeating the above operation, the pump 100 is always variable
Adjust the discharge capacity so that the differential pressure across the throttle 400 is constant.
Variable control.   Therefore, when the pump discharge flow rate is controlled, the pressure
As shown in FIG. 1, the detecting means 600 is in the neutral position,
Roads 612, 613, 614, 620, 621 are in a state where communication is cut off.
Become. Here, the rotating ring 107 is vibrated by the piston 115.
Although a force acts, according to the configuration of the present invention, the pipelines 620 and 621 are
Since the communication with the other pipeline is blocked, it becomes oil-tight and
The damping force acts on the vibration force, and the rotating ring
The advantage of preventing vibration of 107 and enabling stable control is
is there.   The variable throttle 400 has its opening area due to the pressure Pi downstream of the throttle.
Is variably controlled. Here, the pressure Pi downstream of the throttle is the power
Flow supplied to the power cylinder 300 of the steering device
Indicates body pressure. Especially in power steering systems
A state where a large amount of working fluid is required, such as when operating a ring
Then, the working fluid pressure need not be so high. However
While steering, keep the state by steering the steering to the limit.
Hold the steering wheel strongly when holding it or when driving on rough roads
High pressure is required, but fluid volume
Does not need much.   In other words, the working flow supplied to the power cylinder 300
The characteristics of the body are shown in Fig. 10. Many at normal discharge pressure
When a large discharge amount is required but a high discharge pressure is required
Therefore, the required discharge amount is reduced. Especially the maximum required discharge pressure
In such a state, almost no discharge amount is required anymore.   In this example, the flow supplied to the power cylinder 300
The variable throttle restricts the opening area of the fluid passage 200 based on the body pressure Pi.
Therefore, the above-mentioned characteristics can be satisfactorily obtained. Only
However, in this example, the variable throttle 400 is the flow discharged from the pump 100.
Opening area so that the product of body pressure P and flow rate Q is constant
The pump 100 operates at the best
Will be retained.   Here, due to the influence of the pump discharge pressure pulsation,
Pressure pulsation is relatively large on the upstream side, but below the variable throttle 400
The pressure pulsation is attenuated by the variable throttle 400 on the flow side.
Therefore, as in the present invention, the variable throttle 400 is set to the pressure Pi downstream of the throttle.
If the opening area is variably controlled, the pump discharge pressure pulsation
The advantage of being able to perform stable control that is less susceptible to
is there.   17 and 18 show an embodiment according to the second invention of the present invention.
Is shown.   In this embodiment, the auxiliary variable diaphragm 8 is further provided downstream of the variable diaphragm 400.
00 is provided, and other configurations are similar to those of the above-described embodiment.
You. The variable throttle 400 is a fluid pressure Pi downstream of the auxiliary variable throttle 800.
Is introduced through the pressure guiding passage 401. Also, the pressure detection means 6
00 is auxiliary variable throttle 800 Fluid pressure Pi downstream and variable throttle 400
The upstream pressure Pd is passed through the first and second signal pressure passages 601 and 602.
And introduce.   Therefore, in this embodiment as well, the pump 100 has both variable throttles.
So that the differential pressure across 400 and 800 is constant
Volume is controlled, and variable throttle 400 is the discharge pressure of pump 100.
The product of P and the discharge flow rate Q is controlled to be constant.   In this example, an auxiliary variable aperture 800 is further provided on top of the above configuration.
Therefore, this auxiliary variable aperture 800 enables power cylinder
The flow rate supplied to the DA300 can be controlled more precisely.
Wear. The auxiliary variable aperture 800 is operated by an electromagnetic solenoid 801.
The diaphragm amount is changed, and the electromagnetic solenoid 801 is
It drives based on the electric signal of. The control unit 802 displays the vehicle speed
Sensor 803, steering angle sensor 804, etc.
Flow supplied to the power cylinder 300 based on the signal of
Calculate optimal body flow. Based on this calculation result, electricity
The signal is supplied to the electromagnetic solenoid, which causes the auxiliary variable diaphragm.
Control the aperture of 800.   19 and 20 show an embodiment according to the third invention of the present invention.
Will be explained. In this embodiment, the relief portion 4 of the variable diaphragm 400 is
One provided with a relief groove 451 that connects the passage 50 and the passage 405.
The other structure is similar to that of the above-described embodiment.   As described above, in the present invention, the discharge flow rate Q of the pump 100
To the characteristics of the working fluid supplied to the power cylinder 300.
The working fluid pressure is maximized because it is controlled together.
In such a state (N in Fig. 10), the pump 100 is required.
The discharge rate is almost zero. This is the variable capacity means 500
To make the eccentricity of the rotating ring 107 almost zero.
Can be achieved.   However, the pump has a volume variation of multiple pressure chambers 190.
Since the fluid is compressed and discharged by the
Discharge pulsation inevitably occurs. The discharge capacity of Popun 100
If there is enough, this discharge pulsation is not a problem,
As mentioned above, when the discharge capacity of the pump 100 is extremely small
The influence of this discharge pulsation becomes relatively large.   Therefore, in this example, the relief groove 451 operates a predetermined amount.
For the fluid, even if the passage portion 405 of the variable throttle 400 is the fluid passage 200
Flows to the relief section 450 side even when the
Like that. That is, the relief groove portion allows the pump 10
The minimum discharge capacity of 0 is compensated. The escape groove
The working fluid discharged to the escape section 450 by the section 451 is then
It is released to the space 106 of the pump 100 or the reservoir tank side.
You.   The escape groove 451 is a sliding pin in the embodiment shown in FIG.
It is formed on the outer circumference of the stone 404 and is shown in Figs. 21 and 22.
Alternatively, it may be formed on the pintle 104 side of the pump 100.
Even in this case, the relief groove portion 451 does not pass through the variable aperture 400.
The flow passage 405 restricts the fluid passage to the maximum
It is formed at a position leading to the escape portion 450 side.   In the above example, the pump 100 is a so-called radius.
I used a le plunger pump, but use another type of pump.
Of course, it is okay. Equipped with variable capacitance function
Basically, what kind of pump
It can also be used in At the same time, the drive source of the pump 100
Is not only the engine 700 for car running described above, but
Data may be used.   The pressure detection means 600 also receives the pressure in the above example.
It was introduced directly through the No. pressure passages 601 and 602, but other pressure
Is converted into an electric signal using a pressure sensor, etc.
It may be configured to detect and compare signals.   Similarly, the variable diaphragm 400 is also mechanically equipped with a spring 407.
Not only the variable throttle but also the electromagnetic solenoid
It may be a diaphragm that can be controlled physically.   Furthermore, the device of the present invention is based on the above-described power steering device.
It goes without saying that there are various uses other than the storage. 〔The invention's effect〕   As described above, in the device of the present invention, the driven actuator is
Pump discharge rate control using the working fluid supplied to
Requires special fluid passages for pump control.
Absent. Therefore, the whole fluid piping is easy and
The work efficiency of the pump is also improved.   In addition, in the present invention, the pump efficiency is almost optimized.
Since the discharge capacity of the pump can be variably controlled, the pump efficiency is
It is always in good condition.   The variable throttle has an opening area that corresponds to the pressure downstream of the throttle.
Variable control of the pump reduces the influence of pump discharge pressure pulsation
Stable control is possible. And, the discharge amount of the pump is limited.
When controlled, pipelines 620 and 621 are oiltight.
Reduce the vibration force acting on the rotating ring of the pump.
Stable control where force acts to prevent vibration of the rotating ring
There is an advantage that is possible.   Further, in the second aspect of the present invention, the discharge efficiency of the pump is improved.
Supply to the driven actuator while keeping it in good condition
The flow rate of the working fluid can be adjusted arbitrarily.   In the third aspect of the present invention, the discharge capacity of the pump is reduced.
Even if the pump is in a dead state, the influence of the pump discharge pulsation can be suppressed.
Can be. Therefore, the driven actuator is always good.
Can be controlled.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view showing an embodiment of the device according to the first invention of the present invention, FIG. 2 is a schematic explanatory view of the device shown in FIG. 1, and FIG. 1 is an explanatory view showing the characteristics of the switching valve shown in FIG. 1, FIG. 4 is a sectional view of the pump shown in FIG. 1, and FIG.
FIG. 6 is a sectional view taken along line VV in FIG. 6, FIG. 6 is a sectional view showing an essential part of the pressure detecting means shown in FIG. 1, and FIG. 7 is a sectional view showing another example of the pressure detecting means shown in FIG. FIG. 9 is a front view showing a main part of still another example of the pressure detecting means, FIG. 9 is a sectional view showing the pressure detecting means using the ring shown in FIG. 8, and FIG. 10 is a discharge amount of the pump shown in FIG. Explanatory diagram showing the relationship between the discharge pressure and
FIG. 11 is an explanatory view showing the shape of the passage portion of the variable throttle shown in FIG. 1, FIGS. 12 to 15 are explanatory views showing other shapes of the passage portion, and FIG. 16 is the above-mentioned FIGS. 11 to 15. FIG. 17 is an explanatory view showing the characteristics of the passage portion shown in FIG. 17, FIG. 17 is a schematic explanatory view showing an embodiment of the device according to the second invention of the present invention, and FIG. 18 is a schematic explanatory view showing the device of FIG. FIGS. 19 and 20 are sectional views showing a variable diaphragm of an apparatus according to the third invention of the present invention, and FIGS. 21 and 22 are sectional views showing other examples of the variable diaphragm shown in FIG. 100 …… Pump, 200 …… Fluid passage, 300 …… Driven actuator, 400 …… Variable throttle, 500 …… Variable capacity means, 600…
... Pressure detection means.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yasuhiro Horiuchi               1-1 1-1 Showacho, Kariya City Nippondenso Co., Ltd.               In the formula company (72) Inventor Masatoshi Kuroyanagi               1-1 1-1 Showacho, Kariya City Nippondenso Co., Ltd.               In the formula company (72) Inventor Kenji Nakamura               1-1 1-1 Showacho, Kariya City Nippondenso Co., Ltd.               In the formula company (72) Inventor Koichi Moriguchi               1-1 1-1 Showacho, Kariya City Nippondenso Co., Ltd.               In the formula company                (56) References JP-A-57-102587 (JP, A)                 JP 58-206893 (JP, A)                 JP-A-58-222989 (JP, A)                 JP-A-50-160807 (JP, A)                 JP-A-58-32985 (JP, A)                 Actual development Sho 48-34121 (JP, U)                 58-158180 (JP, U)                 Actual public Sho 49-11471 (JP, Y1)                 Actual public Sho 43-31492 (JP, Y1)

Claims (1)

(57) [Claims] A pump for compressing and discharging the working fluid, a variable capacity means for controlling the discharge capacity of the pump, a fluid passage for guiding the working fluid discharged from the pump to a driven actuator, and a fluid disposed in the middle of the fluid passage. A variable throttle for varying the passage area and a pressure detecting means for detecting the pressure before and after the variable throttle are provided, and the variable capacity means always has a substantially constant differential pressure before and after the variable throttle based on a signal from the pressure detecting means. The discharge capacity of the pump is varied so that the variable throttle reduces the fluid passage area when the pressure increases based on the pressure downstream of the variable throttle, and increases the fluid passage area when the pressure decreases. The variable displacement means comprises a first drive piston and a second drive piston, and the pressure detection means drives the first drive piston to generate a drive signal. And a second signal pressure passage for deriving a drive signal to the second drive piston, a pressure guiding passage for introducing high pressure, and a discharge passage for discharging high pressure. In addition, the displacement control device for a variable displacement pump is characterized in that the pressure downstream of the variable throttle and the pressure upstream of the variable throttle are detected, and the switching is performed according to the differential pressure before and after the variable throttle. 2. The pressure detecting means derives a signal for reducing the discharge capacity of the pump to the second drive piston when the differential pressure before and after the variable throttle is a predetermined value or more, and when the differential pressure is a predetermined value or less, the second The signal for increasing the discharge capacity of the pump is derived to the drive piston, and when the differential pressure is a predetermined value, the signal to the first drive piston and the second drive piston is cut off. Displacement control device for variable displacement pump. 3. The pump has a rotating ring, a rotor eccentrically arranged in the rotating ring, a cylinder radially formed in the rotor, and a slidably arranged inside the cylinder, the tip of which is the inner surface of the rotating ring. And a piston that abuts against, and the piston reciprocally slides in the cylinder in accordance with the rotation of the rotor to compress and discharge a working fluid, and the first drive piston and the second drive piston include:
The displacement control device for a variable displacement pump according to claim 1 or 2, wherein the displacement control devices are arranged at opposite positions so as to move the rotary ring. 4. A pump for compressing and discharging the working fluid, a variable capacity means for controlling the discharge capacity of the pump, a fluid passage for guiding the working fluid discharged from the pump to a driven actuator, and a fluid disposed in the middle of the fluid passage. A variable throttle for varying the passage area, an auxiliary variable throttle arranged in series in the fluid passage downstream of the variable throttle and controlled based on the operating conditions of the pump, and pressures before and after the variable throttle are detected. Pressure detecting means, the variable capacity means varies the discharge capacity of the pump based on a signal from the pressure detecting means so that the differential pressure before and after the pressure detecting means is always substantially constant, and the variable throttle restricts the discharge capacity. When the pressure becomes high based on the pressure downstream of the variable throttle, the fluid passage area is decreased, and when the pressure becomes low, the fluid passage area is increased. The variable displacement means is configured to change the passage area of the fluid passage to adjust the amount of working fluid guided to the driven actuator, and the variable displacement means includes a first driving piston and a second driving piston. The detection means discharges a first signal pressure passage for deriving a drive signal to the first drive piston, a second signal pressure passage for deriving a drive signal to the second drive piston, a pressure guide passage for introducing a high pressure, and a high pressure. It is configured by a four-way valve for switching to the discharge passage, detects the pressure downstream of the variable throttle and the pressure upstream of the variable throttle, and performs the switching according to the differential pressure before and after the variable throttle. Control device for variable displacement pump. 5. The pressure detecting means derives a signal for reducing the discharge capacity of the pump to the second drive piston when the differential pressure before and after the variable throttle is a predetermined value or more, and when the differential pressure is a predetermined value or less, the second The signal for increasing the discharge capacity of the pump is derived to the drive piston, and when the differential pressure is a predetermined value, the signal to the second drive piston and the second drive piston is cut off. Displacement control device for variable displacement pump. 6. The pump has a rotating ring, a rotor eccentrically arranged in the rotating ring, a cylinder radially formed in the rotor, and a slidably arranged inside the cylinder, the tip of which is the inner surface of the rotating ring. And a piston that abuts against, and the piston reciprocally slides in the cylinder in accordance with the rotation of the rotor to compress and discharge a working fluid, and the first drive piston and the second drive piston include:
The displacement control device for a variable displacement pump according to claim 4 or 5, wherein the displacements are arranged at opposite positions so as to move the rings. 7. A pump for compressing / discharging the working fluid, a variable capacity means for controlling the protruding capacity of the pump, a fluid passage for guiding the working fluid discharged from the pump to a driven actuator, and a fluid disposed in the middle of the fluid passage. A variable throttle for varying the passage area; and a pressure detecting means for detecting the pressure before and after the variable throttle, the variable throttle being slidably arranged in a direction crossing the fluid passage, A passage portion formed in the sliding piston, a relief portion for escaping the working fluid in the fluid passage to the outside, and a relief groove connecting the relief portion and the passage portion are provided. Along with this, the passage area variably controls the opening area of the fluid passage, and the variable capacity means always makes the differential pressure across the pressure detection means substantially constant based on the signal from the pressure detection means. The discharge capacity of the pump is varied, and the variable throttle is configured to decrease the fluid passage area when the pressure becomes higher based on the pressure downstream of the variable throttle, and increase the fluid passage area when the pressure becomes lower. Displacement control device for variable displacement pump. 8. 8. The variable throttle according to claim 7, wherein the variable throttle restricts the working fluid in the fluid passage to the relief portion when the passage portion makes the opening area of the fluid passage equal to or smaller than a predetermined value. Capacity control device for capacity pumps. 9. 9. The displacement control device for a variable displacement pump according to claim 8, wherein the variable throttle allows the working fluid in the fluid passage to escape to the escape portion when the passage portion closes the fluid passage. .