JP3657784B2 - Variable displacement pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a variable displacement vane pump used in a pressure fluid utilizing device such as a power steering device that reduces the steering force of an automobile.
[0002]
[Prior art]
Conventionally, a displacement type vane pump that is directly driven to rotate by an automobile engine has been used as a power steering device pump. Such a displacement pump increases or decreases the discharge flow rate according to the engine speed, so that the steering assist force is increased when the automobile is stopped or traveling at low speed, and the steering assist force is decreased when traveling at high speed. It has a characteristic that contradicts the steering assist force required for the device. Therefore, it is necessary to use a large-capacity pump that can secure a discharge flow rate that can obtain a necessary steering assist force even when traveling at a low speed with a low rotation speed. In addition, a flow rate control valve that controls the discharge flow rate to a certain amount or less is essential for high-speed traveling at a high rotational speed. For this reason, in the capacity type pump, the number of components increases, the structure and the passage configuration are complicated, and it is inevitable that the whole is increased in size and cost.
[0003]
In order to solve such a problem of the displacement pump, a variable displacement vane pump capable of decreasing the discharge flow rate per rotation (cc / rev) in proportion to the increase of the rotation speed is disclosed in, for example, No. 56-143383, Japanese Utility Model Publication No. 63-14078, Japanese Patent Laid-Open No. 7-243385, and the like. These variable displacement pumps do not require a flow rate control valve like the displacement type, prevent waste of driving horsepower and are excellent in energy efficiency, and do not return to the tank side. In addition, it is possible to prevent problems such as leakage inside the pump and a decrease in volumetric efficiency.
[0004]
An example of a vane type oil pump 10 serving as a hydraulic pressure generation source of a power steering apparatus as such a variable displacement vane pump will be briefly described with reference to FIGS. 3 and 4. A front body 11 and a rear body 12 are provided. As is apparent from FIG. 4, the front body 11 has a substantially cup shape as a whole, and a storage space 14 for storing and arranging a pump component 13 as a pump cartridge is formed in the front body 11. The rear body 12 is combined and integrated so as to close the open end. The front body 11 has bearings 16a, 16b, and 16c (16b on the rear body 12 side) in a state where a drive shaft 16 for rotating the rotor 15 that is a rotor of the pump component 13 from the outside passes therethrough. 16c is rotatably supported by a pressure plate 20 (to be described later).
[0005]
Reference numeral 17 denotes a cam ring that has an inner cam surface 17 a that is fitted on the outer periphery of the rotor 15 having the vane 15 a and that forms a pump chamber 18 between the inner cam surface 17 a and the rotor 15. As will be described later, the cam ring 17 is disposed so as to be swingable and displaceable in an adapter ring 19 provided in a fitted state on the inner wall of the storage space 14 so as to vary the volume of the pump chamber 18. .
The adapter ring 19 is used to hold the cam ring 17 in the housing space 14 of the body 11 so that the cam ring 17 can be swung. The adapter ring 19 is omitted, and the cam ring 17 is swung directly into the body 11. It can also be held displaceably.
[0006]
Reference numeral 20 denotes a pressure plate that is arranged in pressure contact with the front body 11 side of the pump cartridge (pump component 13) constituted by the rotor 15, the cam ring 17 and the adapter ring 19 described above. The end surface of the rear body 12 also serving as a side plate is pressed against the opposite side surface of the pump cartridge, and a required assembly state is obtained by integrally assembling the front body 11 and the rear body 12. The pump component 13 is constituted by these members.
[0007]
The pressure plate 20 and the rear body 12 also serving as a side plate stacked on the cam plate 17 are a swing support pin, which will be described later, that functions as a pivot support, positioning pin, and seal pin for swing displacement of the cam ring 17. 21 and an appropriate non-rotating means (not shown) are integrally assembled and fixed in a state of being positioned in the rotational direction.
[0008]
Reference numeral 23 denotes a pump discharge side pressure chamber formed on the bottom side of the storage space 14 of the front body 11, and the pump discharge side pressure acts on the pressure plate 20 by the pressure chamber 23. Reference numeral 24 denotes a pump discharge side opening formed in the pressure plate 20 so as to open the pump discharge side pressure chamber 23 to the pump discharge side region 18B of the pump chamber 18 and guide pressure oil from the pump discharge side region 18B.
[0009]
4 is a pump suction port provided in a part of the front body 11 as shown in FIG. 4, and the suction side fluid flowing in from the suction port 25 passes through a valve hole 30a of the control valve 30 described later and passes through the front side. The pump suction side passage 25a formed in the body 11 and the passages 25b and 25c formed continuously in the rear body 12 through the pump suction side passage 25a and the pump suction side opening 26 opening in the end surface of the rear body 12 through the pump suction side opening 26 It is supplied to the suction side region 18A.
[0010]
Reference numeral 28 denotes a discharge port that is opened by a plug 28 a provided on the side of the front body 11. The discharge port 28 includes a pump discharge side passage 24, a pump discharge side pressure chamber 23, a fluid passage hole 29 formed in a different position of the pressure plate 20, a second fluid pressure chamber 37 described later, A pump that is fed through a spring chamber 42 a by a plug 42 that houses a spring 41 that biases the cam ring 17, a notch groove 43 formed in the front body 11, and passage holes 44, 45, 28 b formed in the body 11. The discharge side fluid pressure is fed to a hydraulic device such as a power steering device (indicated by PS in the figure) (not shown).
[0011]
In the above-described pump discharge side passages (24, 23, 29, 42a, 43, 44, 45, 28b), the opening area is defined by the fluid passage hole 29 that opens to the second fluid pressure chamber 37 and the side surface portion of the cam ring 17. A variable metering orifice 40 that can increase or decrease the angle is formed. The variable metering orifice 40 is configured by opening and closing the passage hole 29 at the side wall portion with the swinging displacement of the cam ring 17. If the orifice 40 is formed in an appropriate shape whose opening and closing amount is controlled in accordance with the fluid pressure on the pump discharge side, the swing displacement of the cam ring 17 can be controlled to a desired state, and the flow rate characteristic can be improved. Diversification is possible.
[0012]
Reference numeral 30 denotes a control valve disposed substantially orthogonally above the storage space 14 in the front body 11. The control valve 30 includes a variable metering orifice 29 provided in the middle of the pump discharge side passage (24, 23, 29, 42a, 43, 44, 45, 28b) in a valve hole 30a formed in the body 11. A spool 32 that slides by the pressure difference between the upper and downstream sides and the biasing force of the spring 31 is provided. The control valve 30 performs fluid pressure control for swinging and displacing the cam ring 17 with respect to the rotor 15 in the pump body 11 (adapter ring 19) by a variable metering orifice 40 described later.
[0013]
In the control valve 30, the variable metering orifice is provided in one chamber (left chamber in FIG. 3) 32a of the spool 32 via fluid passages 46 and 47 extending from the pressure chamber 23 on the pump discharge side. 40 upstream fluid pressure is introduced. In the figure, reference numeral 33 denotes a plug for closing the valve hole 30a having a rod 33a for locking the position of the spool 32 to the left in the valve hole 30a at a position where the opening end of the fluid passage 47 is not closed.
[0014]
In the other chamber (right chamber in FIG. 3) 32b of the spool 32, a spring 31 is disposed and the fluid pressure downstream of the variable metering orifice 40 described above is in the middle of the passage leading to the discharge port 28, that is, The second fluid pressure chamber 37 is led through a fluid passage 19 a formed between the body 11 and the adapter ring 19 and a fluid passage 34 formed in the body 11.
As described above, the pump suction side passage 25a that continues to the suction port 25 is formed in the substantially central portion of the valve hole 30a. The pump suction side passage 25a passes through the annular space formed by the annular groove 32c of the spool 32 and passes through the suction side. Fluid is fed.
[0015]
A first fluid pressure chamber 36 (described later) formed between the adapter ring 19 and the cam ring 17 is connected between the opening of the suction side passage 25a and the opening of the discharge side fluid passage 47. As shown in FIG. 3, the fluid passage 19b of the adapter ring 19 and the fluid passage 35 formed in the body 11 are always open and communicated with the pump suction-side passage 25a by the land portion 32d. Is introduced into the first fluid pressure chamber 36. When the spool 32 moves rightward by a predetermined amount or more, the spool 32 is disconnected from the pump suction side, and the fluid pressure on the pump discharge side is supplied to the first fluid pressure chamber 36.
In the figure, 34a is a damper orifice part.
[0016]
Reference numerals 36 and 37 denote the left and right sides of the rocking fulcrum pin 21 and the sealing material 38 provided at the substantially axially symmetrical position between the outer peripheral portion of the cam ring 17 and the inner peripheral wall portion of the body 11 (adapter ring 19). In the first and second fluid pressure chambers formed in a divided manner, the pump suction side upstream of the variable metering orifice 40 or the pump discharge side upstream of the variable metering orifice 40 in accordance with the operation of the control valve 30 described above. The fluid pressure is introduced into the second fluid pressure chamber 37 by the pump discharge side fluid pressure downstream of the variable metering orifice 40.
Here, on the outer peripheral wall portion of the cam ring 17, a concave groove or the like of about a half circumference is provided along the circumferential direction so that the first fluid pressure chamber 36 can be secured even when contacting the adapter ring 19. Good.
[0017]
The fluid passage hole 29 constituting the variable metering orifice 40 is started up so as to obtain a predetermined flow rate when the rotational speed is low due to an opening area that is changed by being blocked by the cam ring 17, and becomes higher than a certain level. In this case, the flow rate is reduced, and a flow rate of about half of the initial flow rate is obtained at a predetermined rotation speed or higher. Such a flow rate characteristic is shown in FIG.
In the vane type variable displacement pump 10 as described above, configurations other than those described above are well known in the art, and a specific description thereof will be omitted here.
[0018]
According to the vane pump 10 having the above-described configuration, the drive shaft 16 rotates the rotor 15 while moving the vane 15a in and out, so that the pressure oil as the working fluid from the suction port 25 is supplied to the passages 25a, 25b, The air is sucked into the pump chamber 18 through the opening 25c and sent to the pump discharge side pressure chamber 23 from the discharge side passage 24, and then discharged from the discharge port 28 and fed to the power steering device PS and the like.
[0019]
The control valve 30 described above is operated by the differential pressure on the upstream side and the downstream side of the variable metering orifice 40 provided in the middle of the pump discharge side passage, and fluid pressure corresponding to the flow rate on the pump discharge side is supplied to the cam ring 17. By introducing it into the first and second fluid pressure chambers 36 and 37 at the outer side, the cam ring 17 is oscillated and displaced, and the volume of the pump chamber 18 is maintained at a required size.
[0020]
For example, when the rotational speed of the engine is small, the cam ring 17 is kept displaced to the left in FIG. 3, and the pump chamber 18 is kept at the maximum volume. As a result, the discharge flow rate from the pump 10 increases as the rotational speed increases in FIG. When the rotational speed increases and the pump discharge flow rate exceeds a certain amount, the cam ring 17 is oscillated and displaced to the right in FIG. 3 by the action of the control valve 30, and the volume of the pump chamber 18 is reduced. Keep the discharge flow rate constant.
Further, the variable metering orifice 40 is gradually closed as the cam ring 17 swings, so that the displacement amount of the cam ring 17 is controlled and the pump discharge flow rate is reduced. The flow rate is about half.
[0021]
[Problems to be solved by the invention]
In the conventional variable displacement vane pump 10 as described above, the cam ring 17 that is swingably displaceable in the pump body (adapter ring 19) is provided with the rear body 12 and the pressure as shown in FIGS. It was supported by rocking fulcrum pins 21 provided by fitting both ends into holes (a perfect circular hole having a diameter substantially equal to the outer diameter of the pin 21) 12a, 20a. The cam ring 17 is loaded by engaging the swinging fulcrum pin 21 with a recess 17 d formed on the outer peripheral wall of the cam ring 17.
[0022]
A recess 19d is also formed in the inner peripheral wall portion of the adapter ring 19 corresponding to the swing fulcrum pin 21 described above. However, as described above, the recess 19d is pivotally supported in the holes 12a and 20a of the rear body 12 and the pressure plate 20. A gap is formed between the outer periphery of the pin 21 and the groove bottom of the recess 19d as shown in FIG.
[0023]
The rocking fulcrum pin 21 has a positioning function for positioning the rear body 12 and the pressure plate 20 in the rotational direction. However, if the concentricity of the holes 12a and 20a formed in these pins is shifted, the pin 21 is in a normal posture. Further, the cam ring 17 supported by the pin 21 may fall down in the axial direction at the other end corresponding to the posture of the pin 21 as indicated by an arrow in FIG.
[0024]
When the cam ring 17 is in such a tilted state, when the cam ring 17 is about to swing by the variable metering orifice 30 and the control valve 30, a part of the cam ring 17 comes into contact with the rear body 12 and the pressure plate 20 to be caught. As a result, the cam ring 17 may not swing smoothly. In such a state, as shown by the wavy line in FIG. 5B, the discharge flow rate from the pump 10 intermittently increases and decreases, and so-called flow rate jumping may occur.
[0025]
Further, in the swing fulcrum pin 21 as described above, since the portions other than the shaft support portions at both ends are opposed to the recess portion 19d of the adapter ring 19 via a gap, when a load acts on the cam ring 17 from the inside, There is also a possibility that the outer peripheral wall portion of the cam ring 17 is curved as shown by an imaginary line in FIG. When deformed in this way, a part of the swing fulcrum pin 21 comes into sliding contact with the inner walls and edges of the holes 12a and 20a of the rear body 12 and the pressure plate 20, and the movement of the swing fulcrum pin 21 and the cam ring 17 is hindered. There was also a risk of being
Further, according to such a swing fulcrum pin 21, there is a problem that the pin 21 and the holes 12a and 20a are worn.
[0026]
Further, according to the swing fulcrum pin 21 described above, since all the loads acting on the cam ring 17 are received, there are space restrictions on the rear body 12 and the holes 12a and 20a of the pressure plate 20, so this portion Insufficient strength is liable to occur, the shaft support portion of the swing fulcrum pin 21 may be damaged, and the pressure of the pump cannot be increased.
[0027]
Furthermore, according to the variable displacement pump 10 described above, the cam ring 17 is supported so as to be swingable with respect to the rotor 15, and the pump chamber 18 is formed at a biased position closer to one side of the rotor 15. Therefore, the load acting on the rocking fulcrum pin 21 via the cam ring 17 often acts in an unbalanced manner from a plurality of directions, and there is a fluctuation range, so that the cam ring 17 is supported and the cam ring 17 is smoothly swung. There was also a problem that it was difficult to obtain.
[0028]
The present invention has been made in view of such circumstances, and in a variable displacement pump using a swinging fulcrum pin as a swinging fulcrum of a cam ring, the jumping phenomenon of the flow rate that has conventionally occurred when necessary is prevented, and the flow rate from the pump It is an object of the present invention to provide a variable displacement pump capable of improving the characteristics and improving the processing and assembling in the support portion of the swing fulcrum pin.
[0029]
[Means for Solving the Problems]
  In order to meet such a demand, the variable displacement pump according to the present invention is:Have vanesIt is fitted so as to form a pump chamber between a rotor that is rotatable in the pump body and an outer peripheral portion closer to one side of the rotor, and is disposed in the pump body so as to be swingable and displaceable by a swinging fulcrum pin. And a cam ring that is urged in the direction in which the pump chamber volume is maximized, and first and second fluid pressure chambers that are divided and formed between the outer periphery of the cam ring and the pump body. In the variable displacement pump that varies the pump discharge flow rate by moving and moving the cam ring according to the fluid pressure difference between the fluid pressure chambers, the swing fulcrum pin is formed by a recess formed on the inner wall of the cam ring housing portion of the pump body.DirectlyWhile supportingA plate member for sandwiching a pump component composed of the inner wall of the cam ring storage portion, the cam ring and the rotor from both sides is formed with a substantially oval shaped elongated hole into which the end of the swing fulcrum pin is inserted in a loosely fitted state.It is characterized by that.
[0030]
  Further, according to the present inventionThe variable displacement pump has a roughly oval shape.The outer diameter of the swing fulcrum pinInAnd a shape having a parallel portion substantially parallel to the direction of the load acting on the inner peripheral portion of the cam ring.
  Further, in the variable displacement pump according to the present invention, a recess for supporting the swing fulcrum pin is formed in an inner peripheral wall portion of an adapter ring provided in the pump body, or both ends of the swing fulcrum pin are engaged. A substantially oblong slot to be inserted is provided on the end face of the pump body and the pressure plate for sandwiching the pump components from both sides.
  Furthermore, the variable displacement pump according to the present invention includes a pump body, a drive shaft supported by the pump body, a rotor provided in the pump body and driven to rotate by the drive shaft, and the rotor A vane provided so as to be movable in and out in a radial direction, a cam ring that is provided in a freely swingable manner in the pump body, is formed in an annular shape, and forms a pump chamber together with the rotor and vane on the inner peripheral side; A plate member having a pump suction side opening that opens to a region in which the volume in the pump chamber increases; a pump discharge side opening that opens to a region in which the volume in the pump chamber decreases; a recess formed in the pump body; A swing fulcrum pin provided between the cam ring and for swingably supporting the cam ring; A seal member provided on the circumferential side and separating the outer circumferential side space of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber, wherein the first fluid pressure chamber and the second fluid pressure chamber In the vane pump in which the cam ring is swung by the fluid pressure guided to the fluid pressure chamber to change the volume of the pump chamber, the plate member is a hole into which the end of the swing fulcrum pin is inserted in a loosely fitted state. The load applied to the swing fulcrum pin from the cam ring is received only by the recess. The hole is formed in a long hole shape that is long in the direction of the load applied to the cam ring.
  In addition, the variable displacement pump according to the present invention includes a pump body, a drive shaft that is pivotally supported by the pump body, an adapter ring that is provided in the pump body and is formed in an annular shape, and the adapter ring. A rotor that is rotationally driven by the drive shaft, a vane that is provided in the rotor so as to be movable in and out in a radial direction, and is provided in a swingable manner in the adapter ring, and is formed in an annular shape, A cam ring that forms a pump chamber together with the rotor and vane on the inner peripheral side, and a recess formed on the inner peripheral side of the adapter ring and the cam ring, and directly supports the cam ring in a freely swingable manner. A swing fulcrum pin, a pump suction side opening that opens in a region where the volume in the pump chamber increases, and a volume in the pump chamber. Provided on the outer peripheral side of the cam ring, provided on the outer peripheral side of the cam ring, and provided on the outer peripheral side of the cam ring. And a seal member that separates the first fluid pressure chamber and the second fluid pressure chamber, and the cam ring is driven by hydraulic pressure guided to the first fluid pressure chamber and the second fluid pressure chamber. Oscillates to change the volume of the pump chamber.
[0031]
According to the present invention, most of the longitudinal direction of the swing fulcrum pin that supports the cam ring so as to be swingably displaceable is supported by the recesses provided in the inner wall of the cam ring storage portion in the pump body, and both end portions of the swing fulcrum pin are It will escape and hold | maintain by the oblong hole of the substantially oval shape formed in the plate member of the both sides which pinch | interpose a pump component.
[0032]
The variable displacement pump is a vane-type oil pump that discharges hydraulic pressure, and is used as, for example, a hydraulic pressure source in a power steering apparatus of an automobile, but is not limited thereto.
The cam ring is supported by a swing fulcrum pin, a part of which is a support shaft portion, in a space provided in the pump body so as to be swingable. First and second cam rings are provided on both sides of a line segment passing through the swing fulcrum pin. The fluid pressure chamber 2 swings by the fluid pressure in the fluid pressure chamber 2 and the urging means attached to the fluid pressure chamber on the low pressure side.
[0033]
Although the case of using a control valve that performs fluid pressure control for swinging the cam ring has been described, the present invention is not limited to this, and this control valve is omitted, for example, in response to the load pressure associated with the operation of the pressure fluid utilizing device. The cam ring may be configured to be oscillated and displaced.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show one embodiment of a variable displacement pump according to the present invention. In these figures, the same or corresponding parts as those in FIG. Detailed description is omitted. 1A, 1B, and 1C are enlarged views of the portion of the cam ring 17 provided with the swing fulcrum pin 21, as in FIG. 6 described above. It is drawn exaggerated than the actual so that the relationship becomes clear.
[0035]
According to the present invention, in the variable displacement vane pump 10 described above, the swing fulcrum pin 21 for supporting the cam ring 17 so as to be swingably displaceable in the pump body (adapter ring 19) is provided inside the adapter ring 19. While supporting by the recessed part 51 formed in the surrounding part, the hole part which engages the both ends of this rocking | fluctuation fulcrum pin 21 is made into the plate member (rear body 12 which also serves as a side plate) which sandwiches the pump component 13 in the pump body. Are formed by substantially oblong elongated holes 52, 52 formed in the end face and the pressure plate 20).
[0036]
That is, the conventional swing fulcrum pin 21 is supported by a circular hole formed in the inner surface of the rear body 12 on both sides of the pump component 13 and the pressure plate 20, and is received in the recess on the adapter ring 19 side. However, in the present invention, on the contrary, the swinging fulcrum pin 21 is directly received and supported by the recess 51 of the adapter ring 19 and both ends are configured to be movable.
[0037]
According to such a configuration, the rocking fulcrum pin 21 is almost held in the longitudinal direction by the groove bottom 51 a of the recess 51, and the rocking fulcrum of the cam ring 17 and between the first and second fluid pressure chambers 36 and 37. The seal pin functions as a positioning pin for the rear body 12 and the pressure plate 20.
[0038]
The long holes 52 and 52 into which both ends of the swing fulcrum pin 21 are engaged are swing fulcrum pin against a load due to discharge pressure or the like in the discharge side region 18B in the pump chamber 18 acting via the cam ring 17. It is formed as a long hole that allows the movement of the end portion of 21. In addition, what is shown by the arrow in FIG.2 (b) is the action direction of the load which acts on this rocking | fluctuation fulcrum pin 21, and it acts with a slight fluctuation range.
For example, it has been confirmed that when the diameter of the swing fulcrum pin 21 is 3φ, the long diameter portion of the oblong oblong hole 52 should be 3.3 mm.
[0039]
Of course, the substantially oblong elongated holes 52, 52 are parallel portions 52a facing each other with a gap corresponding to the outer diameter of the swing fulcrum pin 21 so that the rear body 12 and the pressure plate 20 can be positioned in the rotational direction. , 52b, and the dimension in the short side direction is determined.
These parallel portions 52 a and 52 b extend in the direction in which the discharge pressure in the discharge side region 18 B of the pump chamber 18 acts on the cam ring 17.
[0040]
According to such a configuration, most of the longitudinal direction of the swing fulcrum pin 21 can be supported by the recess 51 of the adapter ring 19, so that the function as the swing fulcrum of the cam ring 17 can be ensured. The pin 21 does not fall down due to the influence of the fluid pressure that fluctuates in the pump discharge side region 18B in the pump chamber 18 that was a problem in the related art, and the cam ring 17 is not tilted. Since the rocking can be smoothly displaced, the flow rate jumping phenomenon can be prevented.
[0041]
Even in the flow rate adjustment range in which the pump discharge flow rate is adjusted by the swing displacement of the cam ring 17 described above, since the cam ring 17 swings smoothly, the flow rate characteristic of the pump can be stabilized.
In addition, according to the above-described configuration, the holes into which the both ends of the swing fulcrum pin 21 are engaged are formed by the elongated holes 52 and 52 that are elongated in the direction of the load applied to the cam ring 17. As compared with the above, it is possible to solve the problem of strength in the pin support portion in the rear body 12 and the pressure plate 20. Furthermore, in addition to this, the support strength of the swing fulcrum pin 21 is also increased, so that the pressure of the pump 10 can be increased.
[0042]
In addition, this invention is not limited to embodiment structure mentioned above, It is free to change and change the shape of each part, a structure, etc. suitably, A various modification example can be considered. For example, in the above-described embodiment, the pump body of the variable displacement pump 10 is exemplified by the front body 11 and the rear body 12. However, the present invention is not limited to this, and the pump has a three-body structure having an intermediate body. It may be a body.
[0043]
Further, in the above-described embodiment, the case where the annular gap space that holds the cam ring 17 so as to be swingable and displaceable is formed between the adapter ring 19, but the present invention is not limited to this, and the adapter ring 19 may be omitted, and the cam ring 17 may be directly held on the inner peripheral wall portion of the front body 11 or the inner peripheral wall portion of the intermediate body so as to be swingable and displaceable in the pump body.
[0044]
Furthermore, in the above-described embodiment, the case where the rotor 15, the cam ring 17, and the adapter ring 19 (pump body) are interposed between the rear body 12 provided as the pump body and the pressure plate 20 facing the rear body 12 has been described. The present invention is not limited to this, and a side plate may be interposed inside the rear body 12 as a separate member.
[0045]
In the above-described embodiment, the case where the rear body 12 and the pressure plate 20 are positioned in the rotational direction by the swing fulcrum pin 21 has been described. However, the present invention is not limited to this, and an appropriate positioning pin is separately provided. It may be provided.
[0046]
Furthermore, in the above-described embodiment, the variable displacement pump 10 has been described as having a structure in which the swing displacement of the cam ring 17 is controlled using the control valve 30, but the present invention is not limited to this, and the control valve 30. Is also applicable to a type in which the cam ring is swung by the load pressure on the pressure fluid utilization device side.
Further, the vane type variable displacement pump 10 having the above-described configuration is not limited to the structure in the above-described embodiment, and various devices other than the power steering device described in the above-described embodiment, You may apply to an apparatus.
[0047]
【The invention's effect】
As described above, according to the variable displacement pump according to the present invention, the oscillating fulcrum pin can be reliably supported, and the oscillating fulcrum pin has fallen or bent due to the load acting from the cam ring side, which has been a problem in the past. It is possible to eliminate the problem of the cam ring swing displacement due to the cam ring falling.
In addition, according to the present invention as described above, it is possible to ensure a smooth rocking displacement of the cam ring, to eliminate the flow rate jumping phenomenon as in the prior art, and to stabilize the flow rate characteristics.
[0048]
In addition, according to the present invention, it is possible to eliminate the problem of strength at the support portion of the swing fulcrum pin in the plate members on both sides sandwiching the pump component, and the pressure of the pump can be increased.
According to the present invention, the cam ring can be oscillated and displaced smoothly so that the flow rate characteristic of the pump can be improved.
[Brief description of the drawings]
FIG. 1 shows an embodiment of a variable displacement pump according to the present invention, and FIG. 1 (a) is an enlarged cross-sectional view exaggerating the support structure of a swing fulcrum pin characterizing the present invention. (B), (c) is a sectional view taken along line Ib-Ib, Ic-Ic in (a).
2A is a transverse sectional view of a variable displacement pump adopting the present invention, and FIG. 2B is an enlarged view of a main part thereof.
FIG. 3 is a cross-sectional view showing the main structure of a conventional variable displacement pump.
4 is a sectional view taken along line IV-IV in FIG. 3 in a conventional variable displacement pump.
5A is a characteristic diagram showing a flow rate characteristic of a variable displacement pump, and FIG. 5B is a characteristic diagram for explaining a conventional defect.
FIG. 6 is an enlarged cross-sectional view of a conventional variable displacement pump exaggerating the actual support portion that supports the cam ring so as to be swingable and displaceable.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Vane type variable displacement pump, 11 ... Front body (pump body), 12 ... Rear body (pump body, side plate, plate member), 13 ... Pump component, 14 ... Storage space, 15 ... Rotor, 15a ... Vanes, 16 ... drive shaft (rotating shaft), 17 ... cam ring, 17a ... cam surface, 18 ... pump chamber, 19 ... adapter ring, 20 ... pressure plate (plate member), 21 ... oscillating fulcrum pin, 23 ... pump discharge Side pressure chamber, 24 ... passage serving as pump discharge side opening, 25 ... suction port, 25a, 25b ... pump suction side passage, 26 ... pump suction side opening, 28 ... pump discharge port, 28a, 28b ... pump discharge side passage, 29 ... Hole portion constituting variable metering orifice, 30 ... Spool type control valve, 31 ... Spring, 32 ... Spool 32a ... one chamber, 32b ... the other chamber, 34 ... fluid passage, 34a ... damper orifice, 35 ... fluid passage, 36, 37 ... first and second fluid pressure chambers, 40 ... variable metering orifice, 51 ... recessed part, 52 ... substantially oblong slot, 52a, 52b ... parallel part.

Claims (6)

A rotor having a vane and rotatable within the pump body;
A direction in which the pump chamber volume is maximized while being fitted to form a pump chamber between the rotor and an outer peripheral portion closer to one side of the rotor so as to be swingable and displaceable by a swing fulcrum pin in the pump body. A cam ring biased by
A first fluid pressure chamber and a second fluid pressure chamber formed separately between the outer periphery of the cam ring and the pump body;
In the variable displacement pump that varies the pump discharge flow rate by moving and moving the cam ring due to the fluid pressure difference between the two fluid pressure chambers,
While directly supporting the rocking fulcrum pin by a recess formed in the inner wall of the cam ring storage portion of the pump body,
A plate member for sandwiching a pump component composed of the inner wall of the cam ring storage portion, the cam ring and the rotor from both sides is formed with a substantially oval shaped elongated hole into which the end of the swing fulcrum pin is inserted in a loosely fitted state. A variable displacement pump characterized by that. The variable displacement pump according to claim 1, wherein
Characterized in that the elongated hole of the substantially oval shape, and formed in a shape having a parallel portion substantially parallel to the direction of the load acting on the inner periphery of Oite opposite vital cam ring to the outer diameter of the rocking fulcrum pin Variable displacement pump. The variable displacement pump according to claim 1 or 2,
A variable displacement pump characterized in that a recess for supporting the swing fulcrum pin is formed in an inner peripheral wall portion of an adapter ring provided in the pump body. A pump body;
A drive shaft pivotally supported by the pump body;
  A rotor provided in the pump body and driven to rotate by the drive shaft;
A vane provided in the rotor so as to be movable in and out in a radial direction;
A cam ring that is swingably provided in the pump body, is formed in an annular shape, and forms a pump chamber together with the rotor and vane on the inner peripheral side;
A plate member having a pump suction side opening that opens to a region in which the volume in the pump chamber increases, and a pump discharge side opening that opens to a region in which the volume in the pump chamber decreases;
A swing fulcrum pin provided between the recess formed in the pump body and the cam ring, and supporting the cam ring in a swingable manner;
A seal member provided on the outer peripheral side of the cam ring and separating the outer peripheral side space of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber;
In the vane pump in which the cam ring is swung by the hydraulic pressure guided to the first fluid pressure chamber and the second fluid pressure chamber, and the volume of the pump chamber is changed.
The plate member includes a hole portion into which an end portion of the swing fulcrum pin is inserted in a loose fit state,
  A variable displacement pump characterized in that a load applied to the swing fulcrum pin from the cam ring is received only by the recess. 5. The variable displacement pump according to claim 4, wherein the hole is formed in a long hole shape that is elongated in a direction in which a load is applied to the cam ring. A pump body;
A drive shaft pivotally supported by the pump body;
An adapter ring provided in the pump body and formed in an annular shape;
A rotor provided in the adapter ring and driven to rotate by the drive shaft;
A vane provided in the rotor so as to be movable in and out in a radial direction;
A cam ring that is swingably provided in the adapter ring, is formed in an annular shape, and forms a pump chamber together with the rotor and vane on the inner peripheral side;
A swing fulcrum pin provided between the recess formed on the inner peripheral side of the adapter ring and the cam ring, and directly supporting the cam ring so as to freely swing;
A pump suction side opening that opens to a region in which the volume in the pump chamber increases, a pump discharge side opening that opens to a region in which the volume in the pump chamber decreases, and a hole into which the swing fulcrum pin is inserted in a loose fit state A plate member comprising:
A seal member provided on the outer peripheral side of the cam ring and separating the outer peripheral side space of the cam ring into a first fluid pressure chamber and a second fluid pressure chamber;
2. A variable displacement pump according to claim 1, wherein the cam ring is swung by a hydraulic pressure guided to the first fluid pressure chamber and the second fluid pressure chamber to change a volume of the pump chamber.

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