JP2005337199A - Variable displacement pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable displacement pump capable of stabilizing delivery amount of fluid by eliminating a clearance between a housing and an outer case. <P>SOLUTION: This variable displacement pump has the housing 12 forming a recessed part, the outer case 16 forming a storage space part 15 between a space part and a recessed part inside it, a rotor 38 having a vane 40, a cam ring 28 forming a suction region 42 for sucking fluid or a delivery region 44 for delivering fluid between the rotor 38 and it and forming a first pressure chamber 32 and a second pressure chamber 34 between the outer case 16 and it, first flow passages 24, 54 for letting fluid flow into the first pressure chamber 32, second flow passages 26, 56 for letting fluid flow into the second pressure chamber 34, and a pressing means 60 for preventing occurrence of a clearance between the outer case 16 and a recessed part by deforming the outer case 16 elastically. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a variable displacement pump used in a pressure fluid utilizing device such as a power steering device that reduces the steering force of an automobile.

  As shown in FIG. 10, the variable displacement pump 100 includes a housing 102. The housing 102 has a recess (not shown), and a cylindrical outer case 104 is attached to the recess. A storage space 106 is formed by the recess of the housing 102 and the space inside the outer case 104. A cam ring 108 is stored in the storage space 106. The cam ring 108 is disposed so as to be swingable between the outer case 104 and the pin 110. A first pressure chamber 112 and a second pressure chamber 114 are formed between the housing 102 and the cam ring 108, respectively. A drive shaft 116 that is rotated by a rotational driving force from the outside is disposed inside the cam ring 108 in the radial direction. A rotor 120 having a plurality of vanes 118 is disposed outside the drive shaft 116 in the radial direction, and rotates with the rotation of the drive shaft 116. Further, between the cam ring 108 and the rotor 120, a suction region 122 for sucking fluid from a drain chamber (not shown) described later, and a discharge for discharging the sucked fluid to a third flow path (not shown) described later. Each region 124 is formed.

The housing 102 is provided with a control valve 126. The control valve 126 includes a spool 128 that slides in a valve hole 130 formed in the housing 102 due to a pressure difference between a fluid pressure in the valve hole 130 and a biasing force of a spring 132. The valve hole 130 and the first pressure chamber 112 are connected by a first flow path 134. Further, the valve hole 130 and the second pressure chamber 114 are connected by a second flow path 136. A discharge chamber 138 is formed in the housing 102. The discharge chamber 138 communicates with the second pressure chamber 114, and a coil spring 140 that biases the cam ring 108 in a predetermined direction through a circular hole 142 formed in the outer case 104 inside the discharge chamber 138. It is stored.
The control valve 126 is connected to a drain chamber (not shown) through which fluid flows from the reservoir tank, and the control valve 126 includes a relief valve (not shown). The control valve 126 is connected to a third flow path (not shown) communicating with the discharge region 124 and the second pressure chamber 114. The other components of the variable displacement pump 100 are the same as those of the conventional variable displacement pump, and thus the description thereof is omitted.
JP-A-7-243385

  Here, a slit communicating with the circular hole is formed in advance in the outer case of the variable displacement pump. As a result, the outer case can be elastically deformed to reduce its diameter and assembled to the housing, and the assembling property of the outer case to the housing can be greatly improved.

However, if a slit is formed in the outer case, the outer case itself is elastically deformed to reduce the diameter, and the outer case is enlarged after assembly, a gap is formed between the outer case and the inner wall surface of the recess of the housing. There is a fear. For this reason, conventionally, a correction jig is inserted into the circular hole of the outer case so that no gap is generated, and a part of the outer case is attached so that no gap is generated between the outer case and the inner wall surface of the recess of the housing. It was corrected by pressing against the housing side.
However, even with correction using a correction jig, a slight gap still occurred between the outer case and the inner wall surface of the recess of the housing.
When a slight gap is generated between the outer case and the inner wall surface of the recess of the housing, the fluid that has passed through the first flow path or the second flow path passes through the gap and enters the second flow path or the first flow path. Since it flows in and may flow into the second pressure chamber or the first pressure chamber, the pressure in the second pressure chamber or the first pressure chamber may increase. When the pressure in the second pressure chamber or the first pressure chamber rises, the balance of the pressure acting on the cam ring is lost, the cam ring moves to the first pressure chamber side or the second pressure chamber side, and the discharge chamber from the second pressure chamber. The discharge amount of the fluid discharged to the nozzle changes. Further, there is a problem that vibration is generated by changing the discharge amount of the fluid discharged into the discharge chamber, and noise is further generated due to the vibration.

  In view of the above circumstances, an object of the present invention is to provide a variable displacement pump that can stabilize the fluid discharge rate by eliminating the gap between the housing and the outer case.

  The invention according to claim 1 is a housing in which a recess is formed, a cylindrical outer case that is attached to the recess and forms a storage space portion by an internal space portion and the recess portion, and rotates in the storage space portion. A rotor having a vane that can be stored, and a storage region that is movably stored in the storage space, and forms a suction region for sucking fluid or a discharge region for discharging fluid between the rotor and the outer case. A cam ring that forms a first pressure chamber and a second pressure chamber therebetween, a first flow path that is formed from the housing to the outer case and allows fluid to flow into the first pressure chamber, and from the housing to the outer A second flow path formed over the case and allowing fluid to flow into the second pressure chamber; and the outer case by elastically deforming the outer case. And having a pressing means for preventing the occurrence of a gap between the over scan and the recess, the.

According to the first aspect of the present invention, for example, the cam ring moves in the storage space along with the rotation of the rotor due to the differential pressure between the first pressure chamber and the second pressure chamber according to the rotational speed of the engine. The movement of the cam ring changes the center-to-center distance between the center of the cam ring and the center of the rotor, and the center-to-center distance changes to change the volumes of the suction region and the discharge region. Thereby, the discharge amount per rotation of the rotor changes.
Here, the outer case is elastically deformed by the pressing means, and the outer case is pressed against the recess. Thereby, a clearance gap does not arise between an outer case and the recessed part of a housing. For this reason, the fluid flowing through the first flow path or the second flow path does not flow into the second flow path or the first flow path through the gap between the outer case and the recess of the housing, and the first pressure The pressure in the chamber and the second pressure chamber does not change unnecessarily.

  According to a second aspect of the present invention, in the variable displacement pump according to the first aspect, the fluid discharged from the second pressure chamber communicates with one of the first pressure chamber or the second pressure chamber to the outside. A discharge chamber that discharges; and a biasing means that is housed in the discharge chamber and biases the cam ring in a predetermined direction. The slit extends in the axial direction in the outer case, and communicates with the slit. An opening for passing the biasing means is formed, and the pressing means is a diameter expanding means that is inserted into the opening to expand the diameter of the outer case.

According to the second aspect of the present invention, when the diameter expanding means as the pressing means is inserted into the opening formed in the outer case, the slit is pushed radially outward and the outer case is expanded. . When the diameter of the outer case is increased, the outer case is pressed against the inner wall surface of the recess of the housing, and a gap can be prevented from being generated between the outer case and the inner wall surface of the recess. As a result, the fluid that has flowed through the first flow path or the second flow path does not flow into the second flow path or the first flow path through the gap between the outer case and the recess of the housing, and the first pressure The pressure in the chamber and the second pressure chamber does not change unnecessarily. As a result, the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber into the discharge chamber can be stabilized. In addition, by stabilizing the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber to the discharge chamber, it is possible to prevent the occurrence of vibrations and thus the generation of noise.
In particular, the opening for inserting the diameter expanding means is formed in advance in the outer case so as to pass the urging means for urging the cam ring in a predetermined direction. Therefore, the opening can be used as it is. Thereby, it is not necessary to separately form an opening for inserting the diameter expanding means into the outer case.

  According to a third aspect of the present invention, in the variable displacement pump according to the second aspect, an inclined portion that is inclined downward toward an insertion direction of the opening is formed at an end portion of the diameter expanding means. It is characterized by.

  According to the third aspect of the present invention, the end of the diameter expanding means is formed with an inclined portion that is inclined downward toward the direction of insertion of the opening, so that the diameter expanding means can be easily inserted into the opening. be able to. Thereby, the diameter expansion means can be easily inserted into the opening manually.

  According to a fourth aspect of the present invention, in the variable displacement pump according to the second or third aspect, the diameter-expanding means is formed in a hollow shape.

  According to the fourth aspect of the present invention, since the diameter expanding means is formed in a hollow shape, another component member (for example, an urging means) can be accommodated inside the diameter expanding means. Thereby, even when the diameter expanding means is accommodated in the discharge chamber and another component member is accommodated, the limited space of the discharge chamber can be used effectively, and the discharge chamber does not need to be enlarged.

  According to a fifth aspect of the present invention, in the variable displacement pump according to any one of the second to fourth aspects, the diameter-expanding means is a cylindrical shape having a diameter larger than the diameter of the opening. The elastic member is characterized in that a notch groove or a slit is formed in the elastic member and opens on the end side in the axial direction of the elastic member.

According to the fifth aspect of the present invention, the diameter of the cylindrical elastic member as the diameter expanding means is larger than the diameter of the opening, and the elastic member is opened to the axial end portion side of the elastic member. Since a notch groove or slit is formed, when an elastic member is inserted into the opening, stress concentration occurs at the notch groove or slit due to the pressure from the opening acting on the elastic member, and elasticity is generated. The member is elastically deformed at the notch groove or slit. When the elastic member is elastically deformed, pressure acts on the opening from the elastic member as a reaction. For this reason, it is possible to prevent the outer case from being enlarged in diameter, and the outer case being pressed against the inner wall surface of the recess of the housing, thereby generating a gap between the outer case and the inner wall surface of the recess. As a result, the fluid that has flowed through the first flow path or the second flow path does not flow into the second flow path or the first flow path through the gap between the outer case and the recess of the housing, and the first pressure The pressure in the chamber and the second pressure chamber does not change unnecessarily. As a result, the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber into the discharge chamber can be stabilized. In addition, by stabilizing the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber to the discharge chamber, it is possible to prevent the occurrence of vibrations and thus the generation of noise.
In particular, since the diameter expanding means is a cylindrical elastic member, another component member (for example, an urging means) can be accommodated in the space portion inside. Thereby, even when the diameter expanding means is accommodated in the discharge chamber and another component member is accommodated, the limited space of the discharge chamber can be used effectively, and the discharge chamber does not need to be enlarged.

  According to a sixth aspect of the present invention, in the variable displacement pump according to any one of the second to fourth aspects, the diameter expanding means is configured by a cylindrical elastic member, and the elastic member includes the A notch groove or slit is formed which allows elastic deformation of the elastic member by pressure from the opening when inserted into the opening.

According to the sixth aspect of the present invention, since the cylindrical elastic member as the diameter expanding means is formed with a notch groove or slit, when the elastic member is inserted into the opening, it acts on the elastic member. Due to the pressure from the opening, stress concentration occurs at the notch groove or slit, and elastic deformation of the elastic member is allowed at the notch groove or slit. When the elastic deformation of the elastic member is allowed, the elastic member elastically deforms at the notch groove or slit, and pressure acts on the opening from the elastic member as a reaction. For this reason, it is possible to prevent the outer case from being enlarged in diameter, and the outer case being pressed against the inner wall surface of the recess of the housing, thereby generating a gap between the outer case and the inner wall surface of the recess. As a result, the fluid that has flowed through the first flow path or the second flow path does not flow into the second flow path or the first flow path through the gap between the outer case and the recess of the housing, and the first pressure The pressure in the chamber and the second pressure chamber does not change unnecessarily. As a result, the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber into the discharge chamber can be stabilized. In addition, by stabilizing the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber to the discharge chamber, it is possible to prevent the occurrence of vibrations and thus the generation of noise.
In particular, since the diameter expanding means is a cylindrical elastic member, another component member (for example, an urging means) can be accommodated in the space portion inside. Thereby, even when the diameter expanding means is accommodated in the discharge chamber and another component member is accommodated, the limited space of the discharge chamber can be used effectively, and the discharge chamber does not need to be enlarged.

  According to a seventh aspect of the present invention, in the variable capacity pump according to any one of the second to sixth aspects, the diameter-expanding means is pressed against the outer case to press the diameter-expanding means at the opening. It has an insertion maintaining means for maintaining the inserted state.

  According to the invention described in claim 7, the diameter expanding means is pressed by the insertion maintaining means and pressed against the outer case. Thereby, the state where the diameter expanding means is inserted into the opening is maintained. As a result, the diameter expanding means does not fall out of the opening, and a gap can be prevented from being generated between the outer case and the inner wall surface of the recess.

  According to an eighth aspect of the present invention, in the variable displacement pump according to any one of the third to seventh aspects, an end of the inclined portion is formed in a curved shape.

  According to the eighth aspect of the invention, since the end portion of the inclined portion is formed in a curved shape, the end portion of the inclined portion becomes an opening when the diameter expanding means is inserted into the opening of the outer case. It becomes easy to insert.

  According to the first aspect of the present invention, the outer case is elastically deformed by the pressing means, so that no gap is generated between the outer case and the recess of the housing. For this reason, the fluid flowing through the first flow path or the second flow path does not flow into the second flow path or the first flow path through the gap between the outer case and the recess of the housing, and the first pressure The pressure in the chamber and the second pressure chamber does not change unnecessarily.

According to the second aspect of the present invention, the outer case is pressed against the inner wall surface of the concave portion of the housing by inserting the diameter expanding means into the opening formed in the outer case, so that the outer case is pressed between the inner wall surface of the concave portion and the outer case. Therefore, the fluid flowing through the first flow path or the second flow path passes through the gap between the outer case and the concave portion of the housing and enters the second flow path or the first flow path. There is no flow, and the pressure in the first pressure chamber and the second pressure chamber does not change unnecessarily. As a result, the discharge flow rate of the fluid discharged from one of the first pressure chamber and the second pressure chamber to the discharge chamber can be stabilized, the generation of vibration can be prevented, and the generation of noise can be prevented.
In particular, since the opening for inserting the diameter-expanding means is formed in the outer case in advance to pass the biasing means for biasing the cam ring in a predetermined direction, the opening can be used as it is, There is no need to separately form an opening for inserting the diameter expanding means into the outer case.

  According to the third aspect of the present invention, since the inclined portion inclined downward toward the insertion direction of the opening is formed at the end of the diameter expanding means, the diameter expanding means can be easily inserted into the opening. Thereby, the diameter expansion means can be easily inserted into the opening manually.

  In the fourth aspect of the invention, since the diameter expanding means is formed in a hollow shape, another component member (for example, urging means) can be accommodated inside the diameter expanding means. Thereby, even when the diameter expanding means is accommodated in the discharge chamber and another component member is accommodated, the limited space of the discharge chamber can be used effectively, and the discharge chamber does not need to be enlarged.

According to a fifth aspect of the present invention, the diameter of the cylindrical elastic member is larger than the diameter of the opening, and the elastic member is formed with a notch groove or slit that opens on the axial end side of the elastic member. Therefore, when the elastic member is inserted into the opening, the elastic member is elastically deformed at the notch groove or the slit due to the pressure from the opening acting on the elastic member, and as a reaction, the pressure acts on the opening from the elastic member. Thus, the diameter of the outer case is increased. As a result, the outer case can be prevented from being pressed against the inner wall surface of the concave portion of the housing, and a gap is generated between the outer case and the inner wall surface of the concave portion, and has flowed through the first flow path or the second flow path. The fluid does not flow into the second flow path or the first flow path through the gap between the outer case and the recess of the housing, and the pressure in the first pressure chamber and the second pressure chamber does not change unnecessarily. . As a result, the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber into the discharge chamber can be stabilized. In addition, by stabilizing the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber to the discharge chamber, it is possible to prevent the occurrence of vibrations and thus the generation of noise.
In particular, since the diameter expanding means is a cylindrical elastic member, another constituent member (for example, an urging means) can be accommodated in the space inside. Thereby, even when the diameter expanding means is accommodated in the discharge chamber and another component member is accommodated, the limited space of the discharge chamber can be used effectively, and the discharge chamber does not need to be enlarged.

In the invention according to claim 6, since the notched groove or slit is formed in the cylindrical elastic member, when the elastic member is inserted into the opening, the notch groove or slit is caused by the pressure from the opening acting on the elastic member. The elastic member is allowed to be elastically deformed at the portion, and the elastic member is elastically deformed. As a reaction, pressure is applied from the elastic member to the opening, and the outer case is expanded in diameter. As a result, the outer case can be prevented from being pressed against the inner wall surface of the concave portion of the housing, and a gap is generated between the outer case and the inner wall surface of the concave portion, and has flowed through the first flow path or the second flow path. The fluid does not flow into the second flow path or the first flow path through the gap between the outer case and the recess of the housing, and the pressure in the first pressure chamber and the second pressure chamber does not change unnecessarily. . As a result, the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber into the discharge chamber can be stabilized. In addition, by stabilizing the discharge flow rate of the fluid discharged from one of the first pressure chamber or the second pressure chamber to the discharge chamber, it is possible to prevent the occurrence of vibrations and thus the generation of noise.
In particular, since the diameter expanding means is a cylindrical elastic member, another constituent member (for example, an urging means) can be accommodated in the space inside. Thereby, even when the diameter expanding means is accommodated in the discharge chamber and another component member is accommodated, the limited space of the discharge chamber can be used effectively, and the discharge chamber does not need to be enlarged.

  According to the seventh aspect of the present invention, since the insertion maintaining means is provided, the state in which the diameter expanding means is inserted into the opening can be maintained. As a result, the diameter expanding means does not fall out of the opening, and a gap can be prevented from being generated between the outer case and the inner wall surface of the recess.

  In the invention according to claim 8, since the end portion of the inclined portion is formed in a curved shape, the end portion of the inclined portion can be easily inserted into the opening when the diameter expanding means is inserted into the opening of the outer case.

  Next, a variable displacement pump according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the variable displacement pump 10 of this embodiment includes a housing 12. A recess (not shown) is formed in the housing 12, and a metal outer case 16 is inserted into the recess. As shown in FIG. 3, the outer case 16 is formed in a cylindrical shape as a whole. From the viewpoint of improving the assemblability to the housing 12, a part of the outer peripheral surface has its axial direction (arrow in FIG. 3). A slit 18 extending along the (A direction) is formed. For this reason, the outer case 16 is not continuous along the circumferential direction, and is discontinuous at the portion where the slit 18 is formed. The slit ends 18A and 18B of the outer case 16 are separated by a predetermined distance D. The outer case 16 is formed with a circular hole (opening) 20 that communicates with the slit 18. The circular hole 20 is formed through the outer case 16 in the thickness direction. As shown in FIG. 1, a spring pin (diameter expanding means, pressing means) 60 is inserted into the circular hole 20 and a coil spring 22 passes through the circular hole 20 as will be described later. Further, the outer case 16 is formed with a first through hole (first flow path) 24 communicating with a first passage (first flow path) 54 described later. Further, the outer case 16 is formed with a second through hole (second flow path) 26 communicating with a second passage (second flow path) 56 described later.

A storage space 15 is formed by the recess of the housing 12 and the space inside the outer case 16. A cam ring 28 is stored in the storage space 15. The cam ring 28 is disposed so as to be swingable between the outer case 16 and the pin 30. Further, a first pressure chamber 32 and a second pressure chamber 34 are formed between the housing 12 and the cam ring 28, respectively.
Further, a drive shaft 36 that is rotated by a rotational driving force from the outside is disposed inside the cam ring 28 in the radial direction. A rotor 38 having a plurality of vanes 40 is arranged outside the drive shaft 36 in the radial direction, and rotates with the rotation of the drive shaft 36. Further, between the cam ring 28 and the rotor 38, a suction area 42 for sucking fluid from a drain chamber (not shown) described later, and a discharge for discharging the sucked fluid to a third flow path (not shown) described later. Each region 44 is formed.

The housing 12 is provided with a control valve 46. The control valve 46 includes a spool 50 that slides in a valve hole 48 formed in the housing 12 due to a pressure difference between the fluid pressure in the valve hole 48 and the biasing force of the spring 52.
Further, a first passage (first flow path) 54 is formed in the housing 12. The first passage 54 communicates with the first through hole 24 formed in the outer case 16, and the valve hole 48 and the first pressure chamber 32 are connected by the first passage 54 and the first through hole 24. It has become. Further, a second passage (first flow path) 56 is formed in the housing 12. The second passage 56 communicates with the second through hole 26 formed in the outer case 16, and the valve hole 48 and the second pressure chamber 34 are connected by the second passage 56 and the second through hole 26. It has become.
A discharge chamber 58 is formed in the housing 12. The discharge chamber 58 communicates with the second pressure chamber 34, and a cap 66 is fitted in the discharge chamber 58. A storage hole 67 is formed in the cap 66, and the coil spring 22 that biases the cam ring 28 in a predetermined direction is stored in the storage hole 67.
The control valve 46 is connected to a drain chamber (not shown) through which fluid flows from the reservoir tank, and the control valve 46 incorporates a relief valve (not shown). The control valve 46 is connected to a third flow path (not shown) communicating with the discharge region 44 and the second pressure chamber 34.
Also, the other variable displacement pump components are the same as the components of the conventional variable displacement pump, and the description thereof is omitted.

  Next, the main part of the present invention will be described.

As shown in FIGS. 1 and 2, a metal spring pin 60 is inserted into the circular hole 20 formed in the outer case 16. The spring pin 60 is formed of a cylindrical elastic member, and the elastic member includes a hypotenuse 60A inclined downward toward the insertion direction into the circular hole 20, and a radially outer side of the elastic member (in the direction of arrow B in FIG. 2). A projecting portion 60C that projects substantially vertically toward the horizontal direction, and a horizontal portion 60B that is positioned between the oblique side portion 60A and the projecting portion 60C and extends along the axial direction of the elastic member (the direction of arrow C in FIG. 2); have. The diameter of the oblique side portion 60 </ b> A is set to be larger than the diameter of the circular hole 20.
The oblique side portion 60A, the horizontal portion 60B, and the protruding portion 60C are integrally formed so as to be continuous.
Further, a notch groove 61 that extends in the axial direction of the elastic member and opens on one end side is formed in a portion extending from the projecting portion 60C constituting the elastic member to a part of the oblique side portion 60A. . It is sufficient that at least one notch groove 61 is formed, and a plurality of notch grooves 61 may be formed.
Further, the end portion R1 of the oblique side portion 60A is R-processed and formed in a smooth curved shape.
In the state where the spring pin 60 is inserted into the circular hole 20, the protruding portion 60 </ b> C is in contact with the end of the cap 66 disposed in the discharge chamber 58, and the spring pin 60 comes out of the circular hole 20. Is preventing.

  Next, the operation of the variable displacement pump 10 of this embodiment will be described.

  When the variable displacement pump 10 is assembled, the outer case 16 is inserted into the recess of the housing 12. At this time, an external force is applied to the outer case 16, and the outer case 16 is inserted into the recess of the housing 12 in a state where the diameter of the outer case 16 is reduced by a substantially distance D between the slit ends 18A and 18B. When the outer case 16 is inserted into the recess, the acting external force is released. Thereby, even if the outer case 16 is expanded in diameter by the elastic force, it returns to the original state. At this time, the outer peripheral surface of the outer case 16 comes into contact with the inner wall surface 14A of the recess.

Next, as shown in FIG. 4, the spring pin 60 is inserted into the circular hole 20 formed in the outer case 16. At this time, it is inserted into the circular hole 20 from the tip end portion R1 of the oblique side portion 60A. Here, the oblique side portion 60A is inclined by a predetermined angle α (see FIG. 2), and the distal end portion R1 of the oblique side portion 60A is formed in a curved shape, so that the spring pin 60 can be easily formed in the circular hole 20. Can be inserted.
As shown in FIG. 5, when the oblique side portion 60A of the spring pin 60 is inserted into the circular hole 20, the inner peripheral surface 21 of the circular hole 20 moves on the oblique side portion 60A in the direction of increasing the inclination. At this time, pressure acts on the oblique side portion 60 </ b> A from the inner peripheral surface 21 of the circular hole 20. When pressure acts on the oblique side portion 60A from the inner peripheral surface 21 of the circular hole 20, since the notch groove 61 is formed in the spring pin 60, stress concentration occurs at the notch groove 61, and the spring pin 60 It is elastically deformed at the part of the notch groove 61. When the spring pin 60 is elastically deformed at the notch groove 61, a pressure is applied from the spring pin 60 to the inner peripheral surface 21 of the circular hole 20 as a reaction. For this reason, a force is applied to the outer case 16 from the oblique side portion 60A in the direction in which the slit ends 18A and 18B are separated from each other, and the separation distance D between the slit ends 18A and 18B is increased. Expand the diameter. As a result, the outer peripheral surface of the outer case 16 is pressed against the inner wall surface 14 </ b> A of the recess and is brought into close contact with each other.
In addition, since the protruding portion 60C of the spring pin 60 is in contact with the end portion of the cap 66 in a state where the spring pin 60 is inserted into the circular hole 20, the spring pin 60 is prevented from coming out of the circular hole 20. It is possible to maintain the insertion state of the spring pin 60 into the circular hole 20.

Further, by positioning the outer case 16 on the horizontal portion 60B of the spring pin 60, no pressure acts on the spring pin 60 from the outer case 16 in the direction in which the spring pin 60 comes out of the circular hole 20, and the circle of the spring pin 60 is reduced. The insertion state with respect to the hole 20 can be maintained.
Furthermore, if the spring pin 60 is inserted into the circular hole 20 more than necessary, the outer case 16 will eventually come into contact with the projecting portion 60C, and no further spring pin 60 can be inserted. It is possible to prevent the circular hole 20 from penetrating through.

  As described above, according to the variable displacement pump 10 of the present embodiment, the spring pin 60 is inserted into the circular hole 20 of the outer case 16, and the slit 18 is radially outward (the arrow X1 in FIGS. 1 and 5). X2 direction side) and the outer case 16 is expanded in diameter. When the outer case 16 is enlarged in diameter, it is possible to prevent the outer case 16 from being pressed against the inner wall surface 14A of the recess of the housing 12 and a gap between the outer case 16 and the inner wall surface 14A of the recess. Thereby, the fluid flowing through the first passage 54 or the second passage 56 passes through the gap between the outer peripheral surface of the outer case 16 and the inner wall surface 14 </ b> A of the recess of the housing 12, and thus the second passage 56 or the first passage 54. The pressure in the first pressure chamber 32 and the second pressure chamber 34 does not change unnecessarily. As a result, the discharge flow rate of the fluid discharged from the second pressure chamber 34 to the discharge chamber 58 can be stabilized. In addition, by stabilizing the discharge flow rate of the fluid discharged from the second pressure chamber 34 to the discharge chamber 58, it is possible to prevent the occurrence of vibrations and thus the generation of noise.

  In particular, the circular hole 20 into which the spring pin 60 is inserted is formed in the outer case 16 in advance so as to pass the coil spring 22 that urges the cam ring 28 in a predetermined direction. be able to. Thereby, it is not necessary to separately form the circular hole 20 for inserting the spring pin 60 into the outer case 16.

  In addition, since the spring pin 60 is formed of a cylindrical elastic member, the internal space can be used effectively, and other structural members (such as the coil spring 22) are accommodated in the space. Can be made. Thereby, even when the spring pin 60 is accommodated in the discharge chamber 58 and another component is accommodated, the limited space of the discharge chamber 58 can be used effectively, and the discharge chamber 58 needs to be enlarged. Absent.

  The inner peripheral surface 21 of the circular hole 20 formed in the outer case 16 used in the variable displacement pump 10 of the above embodiment may be configured to be inclined upward toward the radially outer side of the outer case 16. Good. In this case, the inclination angle of the inner peripheral surface 21 of the circular hole 20 is preferably substantially the same as the inclination angle α of the oblique side portion 60A. By inclining the inner peripheral surface 21 of the circular hole 20 formed in the outer case 16 toward the radially outer side of the outer case 16, the spring pin 60 can be further easily inserted into the circular hole 20, and the spring Assembly of the pin 60 to the outer case 16 is facilitated.

  In addition, the outer case 16 and the spring pin 60 used in the variable displacement pump 10 of the above embodiment have been described by taking a metal one as an example. It is not limited to manufacturing.

  Next, a modified example of the spring pin will be described.

As shown in FIGS. 6 and 7, the spring pin 70 includes an annular pin body 72 as a whole. The pin main body 72 is made of metal, and both end portions in the axial direction are formed so as to incline downward toward the outer side in the axial direction (arrow S1 and S2 direction side in FIG. 7).
Further, both end portions R2 and R3 in the axial direction of the pin main body 72 are R-processed and formed so as to have a smooth curved shape.
The pin body 72 is formed with a notch groove 74 that extends in the axial direction of the pin body 72 and opens on one end side. It is sufficient that at least one notch groove 74 is formed, and a plurality of notch grooves 74 may be formed.
Further, the diameter of the pin body 72 is formed to be larger than the diameter of the circular hole 20.
Even when this spring pin 70 is used, the spring pin 70 is inserted into the circular hole 20 (in this case, it may be inserted into the circular hole 20 from the end R2 side, or the circular hole 20 from the end R3 side). The inner peripheral surface 21 of the circular hole 20 moves on the outer peripheral surface of the pin main body 72. At this time, pressure acts from the inner peripheral surface 21 of the circular hole 20 on the outer peripheral surface. To do. When pressure is applied to the outer peripheral surface from the inner peripheral surface 21 of the circular hole 20, the notch groove 74 is formed in the spring pin 70, so stress concentration occurs at the notch groove 74, and the spring pin 70 is cut off. Elastic deformation occurs at the portion of the notch groove 74. When the spring pin 70 is elastically deformed at the portion of the notch groove 74, pressure is applied from the spring pin 70 to the inner peripheral surface 21 of the circular hole 20 as a reaction. For this reason, a force is applied to the outer case 16 in the direction in which the slit ends 18A and 18B are separated from each other, and the separation distance D between the slit ends 18A and 18B is increased, and the outer case 16 is gradually expanded in diameter. Go. As a result, the outer peripheral surface of the outer case 16 is pressed against the inner wall surface 14 </ b> A of the recess and is brought into close contact with each other.
Note that one axial end of the spring pin 70 is in contact with the end of the cap 66 in a state where the spring pin 70 is inserted into the circular hole 20, so that the spring pin 70 comes out of the circular hole 20. Can be prevented.

  Next, another modification of the spring pin will be described.

As shown in FIGS. 8 and 9, the spring pin 80 includes a cylindrical pin body 82. An enlarged diameter portion 84 having a diameter larger than the diameter of the pin body 82 is integrally formed on the outer peripheral surface in the vicinity of the axial end portion of the pin body 82. The outer peripheral surfaces of the pin main body 82 and the enlarged diameter portion 84 are formed horizontally along the axial direction.
Further, the enlarged diameter portion 84 is formed with a notch groove 86 extending in the axial direction of the spring pin 80 and opening on one end side. It is sufficient that at least one notch groove 86 is formed, and a plurality of notch grooves 86 may be formed.
Furthermore, the diameter of the enlarged diameter portion 84 is formed to be larger than the diameter of the circular hole 20.
Also when this spring pin 80 is used, when the spring pin 80 is inserted into the circular hole 20 from the enlarged diameter portion 84 side, the outer case 16 is gradually enlarged in diameter as described above, and the outer case 16 Are pressed against the inner wall surface 14 </ b> A of the recess and are brought into close contact with each other.
Further, in a state where the spring pin 80 is inserted into the circular hole 20, the pin body 82 of the spring pin 80 is stored in the storage hole 67 of the cap 66, and the enlarged diameter portion 84 is in contact with the end portion of the cap 66. Therefore, the spring pin 80 can be prevented from coming out of the circular hole 20.

  In addition, although the description has been given by taking as an example the configuration in which the respective spring pins 60, 70, 80 are formed with notched grooves 61, 74, 86, each spring is replaced with each spring 61, 74, 86. Slits (not shown) that penetrate the pins 60, 70, 80 in the axial direction may be formed in the spring pins 60, 70, 80, respectively.

It is a schematic sectional drawing which shows the principal part structure of the variable displacement pump which concerns on 1st Embodiment of this invention. It is sectional drawing of the press means used for the variable displacement pump which concerns on one Embodiment of this invention. It is a schematic side view of the outer case used for the variable displacement pump which concerns on one Embodiment of this invention. It is the fragmentary sectional view which showed the state before the press means used for the variable displacement pump which concerns on one Embodiment of this invention is inserted in the opening of an outer case. It is the fragmentary sectional view showing the state where the press means used for the variable capacity type pump concerning one embodiment of the present invention was inserted in the opening of the outer case. It is a schematic sectional drawing which shows the principal part structure of the variable displacement pump used as the modification of the variable displacement pump which concerns on one Embodiment of this invention. It is sectional drawing of the press means used for the variable displacement pump used as the modification of the variable displacement pump which concerns on one Embodiment of this invention. It is a schematic sectional drawing which shows the principal part structure of the variable displacement pump used as the modification of the variable displacement pump which concerns on one Embodiment of this invention. It is sectional drawing of the press means used for the variable displacement pump used as the modification of the variable displacement pump which concerns on one Embodiment of this invention. It is a schematic sectional drawing which shows the principal part structure of the conventional variable displacement pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Variable displacement pump 12 Housing 15 Storage space part 16 Outer case 18 Slit 20 Circular hole (opening)
22 Coil spring (biasing means)
24 1st through-hole (1st flow path)
26 Second through hole (second flow path)
28 Cam ring 32 First pressure chamber 34 Second pressure chamber 38 Rotor 40 Vane 42 Suction area 44 Discharge area 54 First passage (first flow path)
56 Second passage (second flow path)
58 Discharge chamber 60 Spring pin (pressing means, diameter expanding means)
60A oblique side (inclined part)
61 Notch groove 66 Cap (insertion maintaining means)
70 Spring pin (pressing means, diameter expanding means)
74 Notch groove 80 Spring pin (pressing means, diameter expanding means)
86 Notch groove

Claims (8)

A housing in which a recess is formed;
A cylindrical outer case which is attached to the recess and forms a storage space with an internal space and the recess;
A rotor having a vane rotatably housed in the housing space;
A suction region for sucking fluid or a discharge region for discharging fluid is formed between the housing and the rotor, and the first pressure chamber and the second pressure are formed between the outer case and the outer case. A cam ring forming each chamber;
A first flow path formed from the housing to the outer case and allowing fluid to flow into the first pressure chamber;
A second flow path formed from the housing to the outer case and allowing fluid to flow into the second pressure chamber;
Pressing means for preventing the occurrence of a gap between the outer case and the recess by elastically deforming the outer case;
A variable displacement pump characterized by comprising: A discharge chamber communicating with one of the first pressure chamber or the second pressure chamber and discharging the fluid discharged from the second pressure chamber to the outside;
Biasing means housed in the discharge chamber and biasing the cam ring in a predetermined direction;
The outer case is formed with a slit extending in the axial direction and an opening communicating with the slit and passing the biasing means, respectively.
2. The variable displacement pump according to claim 1, wherein the pressing means is a diameter-expanding means that is inserted into the opening and expands the diameter of the outer case.   The variable displacement pump according to claim 2, wherein an inclined portion that is inclined downward toward an insertion direction of the opening is formed at an end portion of the diameter expanding means.   4. The variable displacement pump according to claim 2, wherein the diameter expanding means is formed in a hollow shape. The diameter expanding means is composed of a cylindrical elastic member formed to have a diameter larger than the diameter of the opening,
The variable displacement pump according to any one of claims 2 to 4, wherein the elastic member is formed with a notch groove or a slit that opens toward an axial end portion of the elastic member. . The diameter expanding means is composed of a cylindrical elastic member,
5. A notch groove or a slit that allows elastic deformation of the elastic member by pressure from the opening when inserted into the opening is formed in the elastic member. The variable displacement pump according to any one of claims.   7. The apparatus according to claim 2, further comprising an insertion maintaining unit that presses the diameter expanding unit and presses the diameter increasing unit against the outer case to maintain the state in which the diameter expanding unit is inserted into the opening. The variable displacement pump as described.   The variable displacement pump according to any one of claims 3 to 7, wherein an end portion of the inclined portion is formed in a curved shape.

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