JP2023015422A - Manufacturing method for variable displacement pump, and variable displacement pump - Google Patents

Abstract

To improve the processing work efficiency of the whole storage recessed part of a pump body and to suppress a tool from having a shorter lifetime.SOLUTION: There is provided a manufacturing method for a variable displacement pump that has first to third outward recessed parts 40 to 42 provided on an inner peripheral surface 3b of a pump accommodation chamber 3 of a pump body and arcuately recessed radially outward about a drive shaft, and a fourth outward recessed part 43 at an end part of a spring accommodation chamber 16, and comprises: a first process of processing inner peripheral surfaces and bottom surfaces of the first to fourth outward recessed parts with an end mill tool 50 respective from the axial direction of the pump body; and a second process of processing the inner peripheral surface and bottom surface of the pump accommodation chamber in a peripheral direction except radially outermost regions (deepest parts P1 to P4) of inner peripheral surfaces and bottom surfaces of the first to fourth outward recessed parts processed in the first process.SELECTED DRAWING: Figure 5

Description

The present invention relates to a variable displacement pump manufacturing method and a variable displacement pump.

As a conventional variable displacement pump, for example, one described in Patent Document 1 below is known.

In this variable displacement pump, a cam ring housed in a housing recess of a pump body is rocked via a rocking mechanism in directions in which the eccentricity is increased and decreased. By swinging the cam ring, the amount of change in volume of the plurality of pump chambers is increased or decreased, and the pump discharge pressure is variably controlled according to the engine speed.

Further, on the inner peripheral surface of the housing recess, a plurality of arcuate shapes forming part of the first control oil chamber and the second control oil chamber and formed continuously with the first and second seal sliding contact surfaces are provided. is formed with an outer recess.

The entire surface including the inner bottom surface and the inner peripheral surface of the housing recess and the bottom surface and the inner peripheral surface of each of the outer recesses is finished by milling with one end mill tool.

JP 2017-72035 A

By the way, processing of the housing recess of the variable displacement pump requires highly accurate finish processing in order to ensure the hydraulic characteristics of the pump chamber, and shortening of the processing time is desired.

However, in the conventional variable displacement oil pump, as described above, when cutting the entire surface of each bottom surface and each inner peripheral surface of the housing recess and each outer recess with one end mill tool, The end mill tool once enters the deepest part of each outer recess, and then makes a U-turn to perform machining.

In this way, the end mill tool enters from the inner peripheral surface of the housing recess to the deepest part of each outer recess, and then makes a U-turn to turn back. to stop. Therefore, the processing time for each outer concave portion is longer than that for other portions.

As a result, the entire machining time including the housing recess is lengthened, resulting in a decrease in work efficiency, and an increase in the load on the end mill tool, which may lead to a decrease in tool life.

The present invention has been devised in view of the technical problems of the above-described conventional variable displacement pump manufacturing method, and aims to improve the efficiency of the entire machining work including the housing recess of the pump body and reduce the tool life. It is an object of the present invention to provide a method of manufacturing a variable displacement pump and a variable displacement pump that can be suppressed.

One aspect of the present invention is a pump body having a housing recess, and a plurality of pump chambers arranged in the housing recess and being rotationally driven to change the volumes of a plurality of pump chambers to discharge hydraulic fluid sucked from a suction portion. a pump structure for discharging from a portion; a movable member that accommodates the pump structure inside and swings to vary the amount of volume change of the plurality of pump chambers; A method for manufacturing a variable displacement pump having an outer recess that is recessed radially outward about the rotation axis of the pump structure, the method comprising:
A first step of processing the inner peripheral surface and the bottom surface of the outer recess from the axial direction of the pump body; a second step of processing the inner peripheral surface and the bottom surface of the housing recess from the circumferential direction while avoiding the radially outermost portion;
have.

ADVANTAGE OF THE INVENTION According to one aspect of this invention, it becomes possible to improve the working efficiency of the entire pump body, including the housing recess, and to suppress the decrease in tool life.

FIG. 4 is a front view of the variable displacement pump with the cover member removed; FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 with a cover member attached; It is a front view which shows a pump body simple substance. 4 is a cross-sectional view taken along the line BB of FIG. 3; FIG. A shows the procedure of cutting the inner surface of the pump storage chamber with an end mill tool, and B is an enlarged view of the C part of A. FIG. A is a front view of a pump housing chamber showing a state in which residual portions are formed during cutting in the first step and the second step of the present embodiment, and B is an enlarged view of the D portion of A. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a variable displacement pump and embodiments of a variable displacement pump according to the present invention will be described in detail below with reference to the drawings.

In the following embodiments, the variable displacement pump is used to supply lubricating oil to a valve timing controller (VTC) that controls the opening and closing timing of engine valves and sliding parts of an internal combustion engine for automobiles. An example of application to an oil pump is shown. Further, since the main technique of the present invention is the manufacturing method of the pump body of the variable displacement pump, a detailed description of the pump as a whole is omitted.
[First embodiment]
FIG. 1 is a front view showing the variable displacement pump with the cover member removed, FIG. 2 is a cross-sectional view along line AA of FIG. 1 with the cover member attached, and FIG. 3 is the pump body. FIG. 4 is a front view showing a single unit, and FIG. 4 is a sectional view taken along line BB of FIG.

This variable displacement pump is provided, for example, at the lower end of a cylinder block of an internal combustion engine (not shown), and as shown in FIGS. a pump body 1 provided with a cover member 2 for closing one end opening of the pump body 1; and a drive shaft 4 that is rotationally driven via a gear 24 .

In addition, a movable pump is housed in the pump housing chamber 3 so as to be able to swing, and cooperates with first and second control oil chambers 21 and 22 and a coil spring 23 to be described later to change the amount of volumetric change of the plurality of pump chambers 13 . A cam ring 5, which is a member, is housed on the inner peripheral side of the cam ring 5, and is formed between the cam ring 5 and the cam ring 5 by being rotated clockwise (arrow direction) in FIG. 1 by the drive shaft 4. and a pump structure that performs a pumping action by increasing or decreasing the volume of the plurality of pump chambers 13 .

The pump body 1 is integrally formed of an aluminum alloy material, and in FIG. 1, is formed in a rectangular shape that is elongated in the horizontal direction and whose vertical width is smaller than its horizontal length. It is 2, the pump body 1 has a bearing that rotatably supports one end portion 4a of the drive shaft 4 at a substantially central position of the end wall 1a that constitutes the bottom wall including the bottom surface 3a of the pump housing chamber 3. A hole 1b is provided. Further, at a predetermined position of the inner peripheral surface 3b of the pump accommodating chamber 3, as shown in FIG. A notch is formed.

Further, an arc-shaped first outward concave portion 40 forming a part of a first control oil chamber 21, which will be described later, is formed in a portion of the inner peripheral surface 3b of the pump accommodating chamber 3. As shown in FIG. The first outer concave portion 40 is provided with the first seal-constituting portion 5c, which is a protrusion provided on the outer peripheral portion of the cam ring 5, and is a sliding contact portion provided on the first seal-constituting portion 5c. A first seal sliding contact surface 3c with which the first seal member 10a is in sliding contact is formed.

The first seal sliding contact surface 3c is located on the left half side in FIG. is formed in

The first seal sliding contact surface 3c is formed in an arcuate shape having a predetermined radius r1 from the center of the support groove 1c, and the first seal member 10a can always be in sliding contact within the range in which the cam ring 5 eccentrically swings. It is set to the length in the circumferential direction.

Further, in another portion of the inner peripheral surface 3b of the pump accommodating chamber 3, an arc-shaped second outward recess 41 forming part of a second control oil chamber 22, which will be described later, is formed. The second outward concave portion 41 is provided with a second seal-constituting portion 5d, which is a protrusion provided on the outer peripheral portion of the cam ring 5, and is a sliding contact portion provided on the first seal-constituting portion 5d. A second seal sliding contact surface 3d with which the second seal member 10b is in sliding contact is formed.

The second seal sliding contact surface 3d is formed on the right half side in FIG. is set to have a length in the circumferential direction that allows the second seal member 10b to always slide in the range of eccentric oscillation.

An arc-shaped third outward concave portion 42 forming a low-pressure chamber 25, which will be described later, is formed between the support groove 1c and the first seal sliding contact surface 3c on the inner peripheral surface 3b of the pump accommodating chamber 3. there is

A third seal member 10c, which is a sliding contact portion provided on a third seal-constituting portion 5e, which is a protrusion provided on the outer peripheral portion of the cam ring 5, slides on the inner surface of the third outer recess portion 42, which will be described later. A contacting third seal sliding contact surface 3e is formed.

The third seal sliding contact surface 3e is formed in the shape of an arcuate surface having a predetermined radius r3 from the center of the support groove 1c, and the third seal member 10c can always be slidably contacted within the range in which the cam ring 5 eccentrically swings. It is set to the length in the circumferential direction.

In addition, the relationship of the circumferential lengths of r1, r2, and r3 is r1>r2>r3.

As shown in FIGS. 1 and 3, the third outer recess 42 is formed on the left side of the support groove 1c in the drawing, and is entirely arcuate from the inner peripheral surface 3b of the pump accommodating chamber 3 along the vertical longitudinal direction. is formed in

Further, as shown in FIGS. 1 to 4, on the inner surface of the end wall 1a of the pump body 1, that is, on the bottom surface 3a of the pump housing chamber 3, there is provided an outer peripheral area of the bearing hole 1b for the pump action of the pump structure. A suction port 11a, which is an arc-shaped concave suction portion, is formed in a region (hereinafter referred to as a "suction side region") where the volume of each pump chamber 13 increases accordingly. A discharge port 12a, which is an arc-shaped concave discharge portion, is formed in a region where the volume of each pump chamber 13 is reduced (hereinafter referred to as a "discharge side region"). The intake port 11a and the discharge port 12a are formed by notches so as to face each other substantially vertically with the bearing hole 1b interposed therebetween.

As shown in FIG. 1, the discharge side region in this embodiment is formed between the starting end and the terminal end of the discharge port 12a in the rotational direction of the drive shaft 4 (rotor 6).

As shown in FIG. 3, the suction port 11a has an introduction portion 11b, which is one of the outward concave portions formed so as to bulge toward the spring accommodating chamber 16, which will be described later, at the position on the starting end side in the circumferential direction. are integrated. In the vicinity of the boundary between the introduction portion 11b and the suction port 11a, a suction port 11c is formed through the end wall 1a (bottom surface 3a) of the pump body 1 to open to the outside. Therefore, the oil stored in the oil pan of the internal combustion engine is sucked into each pump chamber 13 related to the suction area through the suction port 11c and the suction port 11a based on the negative pressure generated by the pump action of the pump assembly. It's like

The discharge port 12a has a discharge port 12b extending through the end wall 1a (bottom surface 3a) of the pump body 1 and opening to the outside. Therefore, the oil pressurized by the pumping action of the pump structure and discharged to the discharge port 12a flows from the main oil gallery through the discharge passage (not shown) provided inside the cylinder block from the discharge port 12b into the engine. It is supplied to each sliding part, VTC, and the like. An oil cooler and an oil filter are provided downstream of the discharge passage.

As shown in FIG. 3, the bottom surface 3a of the pump housing chamber 3 is formed with a communication groove 15 for communicating the discharge port 12a and the bearing hole 1b. By supplying oil from the discharge port 12a to the bearing hole 1b through the communication groove 15 and also to the side portions of the rotor 6 and each vane 7, good lubrication of each sliding portion is ensured. there is

As shown in FIGS. 1 and 2, the pump assembly is rotatably accommodated on the inner peripheral side of the cam ring 5, and includes a rotor 6 whose central portion is coupled to the outer periphery of the drive shaft 4, and an outer peripheral portion of the rotor 6. A pair of ring members which are smaller in diameter than the rotor 6 and are arranged on both sides of the rotor 6 on the inner peripheral side of the rotor 6. 8, 8 and .

As shown in FIG. 1, the rotor 6 has a plurality of slits 6a formed radially outward from the center thereof, and a back pressure chamber 6b having a substantially circular cross section for introducing the discharge oil into the inner base end portion of the plurality of slits 6a. is provided.

Each vane 7 is pushed outward by the centrifugal force accompanying the rotation of the rotor 6 and the pressure in the back pressure chamber 6b, so that the tip surface of each vane is in sliding contact with the inner peripheral surface of the cam ring 5, and the base end surface of each vane is It is adapted to be in sliding contact with the outer peripheral surface of each ring member 8 , 8 .

As shown in FIG. 2 , the cover member 2 has a substantially plate-like shape and is formed in a rectangular shape elongated in the left-right direction following the outer shape of the pump body 1 . The cover member 2 is attached to the mounting surface 1g of the pump body 1 on the side of the opening of the pump accommodating chamber 3 by means of a plurality of bolts (not shown). A bearing hole 2a for rotatably supporting the large-diameter end portion 4b of the drive shaft 4 is formed through the pump body 1 at a position facing the bearing hole 1b. Similarly to the pump body 1, the inner surface 2b of the cover member 2 also has a suction port 11a', a discharge port 12a', and communication grooves that correspond to the suction port 11a, the discharge port 12a, and the communication groove 15 of the pump body 1. They are arranged facing each other.

The suction port and the discharge port may be formed on either the pump body 1 side or the cover member 2 side.

Further, the cover member 2 is provided with a pilot valve (not shown) which is a control mechanism for controlling the supply and discharge of hydraulic pressure to the second control oil chamber 22 to be described later, or cutting off the supply of the hydraulic pressure. A control pressure introduction passage (not shown) formed between the pilot valve and the discharge passage is provided with a switching mechanism for switching and controlling the introduction of discharged hydraulic oil to the pilot valve side. An external solenoid valve is provided.

As shown in FIG. 2, the drive shaft 4 has one end 4a with a small diameter supported by a bearing hole 1b in the end wall 1a of the pump body 1, and the other end 4b with a large diameter in the bearing of the cover member 2. It is bearing in the hole 2a. A driven gear 24 that meshes with a driving gear provided on a crankshaft (not shown) is provided on the distal end side of the drive shaft 4 . Therefore, the drive shaft 4 rotates the rotor 6 clockwise (in the direction of the arrow) in FIG. 1 based on the rotational force transmitted from the crankshaft via the gears that are in mesh with each other.

As shown in FIGS. 1 and 2, the cam ring 5 is integrally formed in a cylindrical shape from a so-called sintered alloy. A groove-shaped pivot portion 5a is formed. The cam ring 5 has an arm portion 5b projecting radially from the pivot portion 5a on the opposite side across the center of the cam ring 5. As shown in FIG.

As shown in FIGS. 1 and 3, a spring accommodating chamber 16 is provided at the inner lower end of the pump body 1 so as to face the support groove 1c. A coil spring 23 to which a predetermined set load is applied is elastically mounted in the spring accommodating chamber 16 between one end wall thereof and one side surface of the arm portion 5b. The other end wall of the spring accommodating chamber 16 is configured as a restricting surface 16a that restricts the movement range of the cam ring 5 in the eccentric direction. Further movement (rocking) in direction is restricted. Further, in the spring accommodating chamber 16, the axial end portion facing the introduction portion 11b and the restricting surface 16a serve as the fourth outward recessed portion 43, which is the end point of the machining path of the tool during machining, which will be described later.

In this manner, the cam ring 5 is constantly urged in a direction (clockwise direction in FIG. 1) in which the eccentricity thereof increases via the arm portion 5b by the urging force of the coil spring 23. As shown in FIG. As shown in FIG. 1, when the pump is not in operation, the cam ring 5 is in a state where the other side surface of the arm portion 5b is pressed against the regulating surface 16a, and is regulated at a position where the amount of eccentricity is maximized. It has become so.

The cam ring 5 has three first, second and third seal projections at positions corresponding to the first, second and third seal sliding contact surfaces 3c, 3d and 3e of the pump body 1 on the outer circumference. Constituent portions 5c, 5d, and 5e are provided so as to protrude. Each of the seal-constituting portions 5c to 5e is formed in an arc concentric with each of the seal sliding contact surfaces 3c, 3d and 3e. Seal members 10a, 10b, and 10c are housed and held.

Each of the first to third seal members 10a to 10c is linearly elongated along the axial direction of the cam ring 5 and is made of a fluorine-based resin material having low friction characteristics. In addition, the first to third seal members 10a to 10c are pressed against the seal sliding contact surfaces 3c to 3e by the elastic force of the rubber elastic members provided at the bottoms of the respective seal holding grooves. Liquid-tight seals are provided between the respective seal sliding contact surfaces 3c to 3e. That is, when the cam ring 5 is eccentrically oscillated, the first to third seal members 10a to 10c are in sliding contact with the respective seal sliding contact surfaces 3c to 3e, and the first and second control oil chambers 21 and 22 and the low pressure chamber, which will be described later. 25 is sealed.

Further, between the outer peripheral surface of the cam ring 5 and the inner peripheral surface of the pump body 1, as shown in FIG. 2 control oil chamber 22 and the low pressure chamber 25 are formed.

Specifically, the first control oil chamber 21 is provided between the first seal member 10a and the third seal member 10c, and the second control oil chamber 22 is provided between the pivot pin 9 and the second seal member 10b. is set between Furthermore, the low pressure chamber 25 is provided between the pivot pin 9 and the third seal member 10c.

Therefore, of the outer peripheral surface of the cam ring 5, the first pressure receiving surface 5f facing the first control oil chamber 21 is formed small due to the presence of the low pressure chamber 25 between the pivot pin 9 and the pressure from the pivot pin 9 in the circumferential direction. The second pressure-receiving surface 5g facing the second control oil chamber 22, which extends wide, is formed larger. Therefore, when the same oil pressure (discharge pressure) acts on both the first and second control oil chambers 21 and 22, the cam ring will move in a direction (clockwise in FIG. 1) to increase the eccentricity as a whole. 5 is biased.

The pump discharge pressure is introduced to the first and second control oil chambers 21 and 22 via control pressure introduction passages branched from the discharge passage. That is, the pump discharge pressure is supplied to the first control oil chamber 21 through the first introduction passage, which is one of the branch passages branched from the control pressure introduction passage. On the other hand, the pump discharge pressure is supplied to the second control oil chamber 22 through the second introduction passage, which is the other branch passage, through an electromagnetic switching valve and a pilot valve.

These hydraulic pressures act on the first and second pressure-receiving surfaces 5f and 5g of the cam ring 5 facing the first and second control oil chambers 21 and 22, respectively. ) will be given.

Therefore, in the oil pump, when the biasing force based on the internal pressure of both the control oil chambers 21 and 22 is small with respect to the set load of the coil spring 23, the cam ring 5 is in the maximum eccentric state as shown in FIG. When the biasing force based on the internal pressure of both control oil chambers 21 and 22 exceeds the set load of the coil spring 23 as the pressure rises, the cam ring 5 moves in the concentric direction according to the discharge pressure.

1 to 3, the low-pressure chamber 25 is formed between the outer peripheral surface of the cam ring 5 by the third outer concave portion 42, and is formed through the cover member 2 (not shown). It communicates with the oil pan while being open to the atmosphere through the communication hole. In other words, the low-pressure chamber 25 contains oil leaked from the sliding surfaces (side clearances) between the axial end faces 5h and 5i (see FIG. 2) of the cam ring 5 and the pump body 1 and the cover member 2 due to the operation of the pump. So-called contaminants mixed in the oil flow in, and the oil and contaminants are discharged into the oil pan through the communication holes.

Also, one end of the communication passage is always formed at a position that communicates with the low-pressure chamber 25 without being blocked by the cam ring 5 at any pivotal position of the cam ring 5 .

As shown in FIG. 2, between the first control oil chamber 21 and the second control oil chamber 22 and each pump chamber 13, both axial end surfaces 5h and 5i of the cam ring 5 slide against the axial end surfaces 5h and 5i. A so-called side clearance between the bottom surface 3a of the pump housing chamber 3 of the pump body 1 and the other inner side surface 2b of the cover member 2, which are in contact with each other, seals.

The low-pressure chamber 25 is also sealed from each pump chamber 13 by side clearances between both end surfaces 5 h and 5 i of the cam ring 5 and the bottom surface 3 a of the pump housing chamber 3 and the inner surface 2 b of the cover member 2 .

As shown in FIGS. 1 and 2, the cam ring 5 has a first sealing surface that seals between the first control oil chamber 21 and each of the pump chambers 13 on both end surfaces 5h and 5i that form side clearances. A portion that seals between the second control oil chamber 22 and each pump chamber 13 is defined as a second sealing surface. Further, a portion that seals between the low-pressure chamber 25 in the discharge side region and each pump chamber 13 is configured as a third sealing surface.

Since the pilot valve 30 and the solenoid valve are not directly related to the present invention, they will be briefly described without any particular drawings.

As shown in FIG. 2, the pilot valve 30 includes a cylindrical valve body 31 extending to the outside of the cover member 2, a plug 32 closing the bottom opening of the valve body, and an inner axial direction of the valve body 31. Hydraulic pressure is supplied to and discharged from the second control oil chamber 22 by a pair of first and second lands which are slidably accommodated in a valve accommodation hole formed in the valve body 31 and are in sliding contact with the inner peripheral surface of the valve body 31 . A spool valve body (not shown) used for control is elastically mounted with a predetermined set load between the plug 32 and the spool valve body on the inner circumference of the other end side of the valve body 31, and the spool valve body is moved to the one end side of the valve body 31. It is mainly composed of a valve spring (not shown) that always biases.

The solenoid valve is housed in a valve housing hole (not shown) interposed in the middle of the control pressure introduction passage, and is composed of a cylindrical valve body through which an oil passage is formed along the internal axial direction, and a tip side of the oil passage. A ball valve which is fixed to the inside and has an introduction port, and which is removably attached to a valve seat formed at the opening edge of the inner end of the seat member and serves to open and close the introduction port (not shown). and a solenoid provided at the other end of the valve body.
[Cutting method of pump body]
FIG. 5A shows a procedure for cutting the inner surface of the pump housing chamber with an end mill tool, and B is an enlarged view of part C of A. FIG.

Below, the bottom surface 3a and the inner peripheral surface 3b of the pump housing chamber 3, the four first to fourth outer recesses 40 to 43 (the first to third seal sliding contact surfaces 3c to 3e and the regulating surfaces of the spring housing groove 16) (including each inner peripheral surface and each bottom surface on the side of 16a) will be described with reference to FIGS. 5A and 5B.

The pump body 1 is formed by aluminum die-casting in advance using a casting mold, after which the bottom surface 3a and the inner peripheral surface 3b of the pump housing chamber 3 are cut.

As a processing tool, a general end mill tool 50 (a two-dot chain line in FIGS. 5A and 5B) is used. The end mill tool 50 has a diameter of, for example, 14 mm. Only this single end mill tool 50 is used for machining. The diameter of the end mill tool 50 can be arbitrarily changed according to the size of the pump body 1 (pump housing chamber 3).

As for the processing procedure, as shown in FIG. 5A, first, an end mill tool 50 is used to axially cut four locations of the first to fourth outer recesses 40 to 43 . That is, as shown by the circular dashed lines in the drawing, there are pump housings at a total of four positions: three positions where the first to third outer recesses 40 to 42 are formed and one position of the fourth outer recess 43. Cutting is performed from the axial direction of the chamber 3, that is, from the vertical direction (first step).

Through this first step, the bottom surfaces and inner peripheral surfaces of the first to fourth outer recesses 40 to 43 are machined (first machined surfaces). These first machined surfaces are subjected to finish machining in which the surface roughness and the like are finished with high accuracy.

Next, as shown in FIG. 5A, the position where the bearing hole 1b at the center position of the pump housing chamber 3 is formed is set as the processing start point S of the same end mill tool 50, and the bottom surface 3a is first cut here (second processing). surface). From here, the end mill tool 50 is moved by a predetermined distance in the right-hand horizontal direction indicated by the arrow X1 in the figure, and is rotated about S in the arrow R1 (left) direction while being rotated once for cutting. Subsequently, from the position where the end mill tool 50 has been rotated once, as indicated by the arrow X2, it is further moved in the right horizontal direction by a predetermined distance. From here, it is turned around S again in the direction of the arrow R2 (left) and cut by making one rotation. As a result, most of the inner peripheral portion of the bottom surface 3a of the pump accommodating chamber 3 is finished.

Next, the end mill tool 50 is continuously moved slightly to the right in the drawing from the arrow X2. Subsequently, the end mill tool 50 is rotated leftward by one rotation as indicated by an arrow R3 to cut the bottom surface 3a and the inner peripheral surface 3b of the pump housing chamber 3. As shown in FIG.

Next, the end mill tool 50 is moved to the second seal sliding contact surface 3 d side, and is not moved to the deepest portion P 1 that is the outermost portion in the radial direction of the second outer recess 41 . Before the portion P1, that is, from the second seal sliding contact surface 3d, it is continuously rotated at an angle of about 90 degrees and the angle of the movement trajectory is a circular arc, so that the bottom surface 3a and the inner peripheral surface 3b are cut. process. In other words, since the bottom surface and the inner peripheral surface of the entire circular arc portion of the second outward recess 41 have already been cut in the first step, there is no need for further cutting. Therefore, from here the end mill tool 50 can be moved continuously without stopping the movement.

Further, from here, the end mill tool 50 is moved in the direction of arrow R4, that is, moved along the inner peripheral surface 3b of the pump housing chamber 3 to cut the bottom surface 3a and the inner peripheral surface 3b while cutting the third outer concave portion 42 side. move to Again, the end mill tool 50 is not moved to the deepest part P2 of the third outer recess 42, and is continuously moved at a V-shaped angle of about 80 degrees before the deepest part P2 and the corner of the movement locus is an arc. to cut the bottom surface 3a including the third seal sliding contact surface 3e and the inner peripheral surface 3b (second processed surface).

Subsequently, the end mill tool 50 is moved along the inner peripheral surface 3b of the pump housing chamber 3 as indicated by an arrow R5 to cut the bottom surface 3a and the inner peripheral surface 3b, and is moved to the first outward concave portion 40. Let Again, as shown in FIG. 6, the end mill tool 50 is not moved to the deepest point P3 of the circular arc portion of the first outward recess 40, and the angle of the movement locus is about 120 degrees before the deepest point P3. is continuously moved and rotated at an arc-shaped V-shaped angle, and the bottom surface 3a and the inner peripheral surface 3b thereof are cut.

Further, the end mill tool 50 is similarly moved along the inner peripheral surface 3b as indicated by an arrow R6 to cut the bottom surface 3a and the inner peripheral surface 3b, and toward the fourth outer recess 43 of the spring accommodating chamber 16. move. Again, without moving the end mill tool 50 to the deepest part P4 of the fourth outer recess 43 of the spring housing chamber 16, the bottom surface and the restricting surface 16a are cut just before the deepest part P4. This is the end point E of the cutting by the end mill tool 50 (second step). The bottom surface 3a and the inner peripheral surface 3b processed in the second step are the second processed surfaces.

As described above, in the present embodiment, the cutting of the entire inner surface of the pump housing chamber 3 by the end mill tool 50 is divided into the first step of machining from the axial direction and the second step of machining in the circumferential direction. I tried to do it.

That is, in the first step, the end mill tool 50 is axially moved with respect to the arc-shaped first to fourth outer concave portions 40 to 42 including the seal sliding surfaces 3c to 3d to cut each portion.

In the next second step, the end mill tool 50 is continuously moved in the circumferential direction with respect to the bottom surface 3a and the inner peripheral surface 3b of the pump housing chamber 3 to perform cutting. In such circular arc portions, the end mill tool 50 is not moved to the respective deepest portions P1 to P4, but is continuously bent and moved in a V shape with arcuate corners of the movement locus in front of them.

Therefore, the end mill tool 50 can be moved continuously without stopping at the outer concave portions 40 to 43 in the second step, so that the machining speed is faster than in the conventional method. Therefore, it is possible to shorten the entire cutting time including the bottom surface 3a and the inner peripheral surface 3b of the pump housing chamber 3.

As a result, the flatness and parallelism of the bottom surface 3a and the inner peripheral surface 3b of the pump housing chamber 3 can be maintained with high accuracy, and the working efficiency can be improved.

In addition, as described above, the end mill tool 50 can suppress a decrease in tool life because the load is reduced by shortening the machining operation time.

Moreover, since the same end mill tool 50 is used for the machining operations of the first step and the second step, continuous machining operations can be performed without changing the machining tool in the middle. Time saving is facilitated.

FIG. 6A is a front view of a pump housing chamber showing a state in which residual portions are formed during cutting in the first and second steps of this embodiment, and FIG. 6B is an enlarged view of part D of A. FIG.

During the second step, when the end mill tool 50 is moved from the second outward recess 41 side to the V-shape from the turning movement along the arrow R3, as shown in FIGS. 6A and 6B, the first step A residual portion 33, which is a processing residue, is formed between the cut portion in step 1 and the cut portion in the second step. The residual portion 33 is formed as a projection of several microns as a trajectory mark of the end mill tool 50 and is basically visible. However, the remaining portion 33 is tactile, even if it cannot be visually recognized.

The residual portion 33 is also formed in the first outward recess 40 and the third outward recess 42 as shown in FIG. 6A.

Further, each remaining portion 33 is formed at a position where it does not come into contact with the first to third seal forming portions 5c to 5e while the cam ring 5 is swinging. Therefore, the remaining portion 33 does not affect the pump performance such as the swingability and sealing performance of the cam ring 5 .

The remaining portions 33 are formed in the vicinity of the seal sliding contact surfaces 3c to 3e, but are formed at positions where they do not contact the seal members 10a to 10c in the axial direction within the swinging range of the cam ring 5. there is Therefore, the remaining portions 33 do not affect the sealing performance of the seal sliding contact surfaces 3c to 3e of the seal members 10a to 10c while the cam ring 5 is swinging.

The present invention is not limited to the configuration of the above embodiment, and for example, the size of the pump storage chamber 3 can be arbitrarily changed according to the pump capacity.

Also, although the end mill tool 50 is used as the processing tool, other tools may be used.

Furthermore, in this embodiment, the remaining portion 33 is formed after processing, but depending on the processing method, it is possible to adopt a method in which the remaining portion is not formed.

As the manufacturing method of the variable displacement pump and the variable displacement pump based on the embodiment described above, for example, the following aspects are conceivable.

In one aspect, a pump body having a housing recess, and a plurality of pump chambers arranged in the housing recess and being rotationally driven to change the volumes of the plurality of pump chambers to pump the hydraulic fluid sucked from the suction portion to the discharge portion. a pump structure for discharging, a movable member that accommodates the pump structure inside and swings to vary the amount of volumetric change of the plurality of pump chambers, and a movable member that is provided in the housing recess and comprises the pump structure. A method for manufacturing a variable displacement pump having an outer concave portion that is concave radially outward about the rotation axis of the body, the method comprising:
A first step of processing the inner peripheral surface and the bottom surface of the outer recess from the axial direction of the pump body; and a second step of processing the inner peripheral surface and the bottom surface of the housing recess from the circumferential direction, avoiding the radially outermost portion.
According to this aspect of the present invention, for example, in a rough material of a pump body formed by casting, in the first step, the inner peripheral surface and the bottom surface of the outer recess are machined with a machining tool from the axial direction of the pump body. . Next, in the second step, the inner peripheral surface and the bottom surface of the housing recess are machined from the circumferential direction of the processing tool. instead of moving it to the deepest part of the housing and returning it, it is moved to the vicinity of the entrance of the outer recess on the side of the accommodation recess, and then it is turned in an arc shape from there. As a result, the flatness and parallelism of the bottom surfaces and inner peripheral surfaces of the housing recess and the outer recess can be maintained with high accuracy, and the life of the tool can be extended.

More preferably, the first step and the second step use the same working tool.

According to this aspect of the present invention, by using the same machining tool, continuous machining can be performed without exchanging the machining tool, so that the machining time can be shortened.

More preferably, the machining tool in the first step and the machining tool in the second step are end mills having the same diameter.

More preferably, the movable member includes an annular main body that accommodates the pump structure therein, and a radially outward protruding portion from the outer periphery of the main body to enter the outer concave portion and enter the outer concave portion. and a protrusion having a sliding contact portion that slides on a portion of the inner peripheral surface.

More preferably, the bottom surface of the outer recess is formed between the processed surface formed in the first step and the processed surface formed in the second step by the first step and the second step. It has a protrusion-like machining residue that is not visible.

More preferably, the unprocessed portion is formed at a position that does not come into axial contact with the protrusion within the swinging range of the movable member.

According to this aspect of the present invention, although there is an unprocessed portion, since it is formed at a position that does not come into contact with the protrusion during swinging of the movable member, it is possible to improve the sealing performance and the mobility of the movable member. No impact on performance.

More preferably, the slidable contact portion is a seal member that is in slidable contact with the inner peripheral surface of the housing recess, the projecting portion of the movable member has a seal recess into which the seal member is received, and the processing residue is , at a position where it does not come into contact with the seal member in the axial direction within the swinging range of the movable member.

According to this aspect of the present invention, although there is an unprocessed portion, it is formed at a position where it does not come into contact with the sealing member, so that it does not affect the sealing performance of the sealing member.

More preferably, a plurality of outer recesses are formed on the inner peripheral surface of the accommodation recess.

Another preferred aspect is a pump body having a housing recess,
a pump structure arranged in the accommodation recess and being rotationally driven to change the volumes of a plurality of pump chambers to discharge the hydraulic fluid sucked from the suction part from the discharge part; and a protrusion projecting radially outward from the outer circumference of the main body and having a sliding contact portion that slides in contact with the accommodating recess. a movable member that varies the amount of change in volume; A variable displacement pump comprising a recess,
The outer recess has a first processed surface that is a processed surface of the bottom surface and the inner peripheral surface of the outer recess, and the housing recess has a second processed surface that is a processed surface of the bottom surface and the inner peripheral surface of the storage recess. It has a machined surface, and a machining residue is formed between the bottom surface of the first machined surface of the outer recess and the bottom surface of the second machined surface of the housing recess.

More preferably, the unprocessed portion is formed at a position that does not come into axial contact with the protrusion within the swinging range of the movable member.

More preferably, the sliding contact portion is constituted by a seal member that is in sliding contact with the inner peripheral surface of the outer concave portion, and the projecting portion of the movable member has a seal concave portion on the outer surface of which the seal member is held. , the unprocessed portion is formed at a position where it does not come into contact with the seal member in the axial direction within the swinging range of the movable member.

DESCRIPTION OF SYMBOLS 1... Pump body (pump housing) 3c to 3e... First seal sliding contact surface (outer concave portion) 2... Cover member (pump housing) 3... Pump accommodating chamber (accommodating concave portion) 3a... Bottom surface 3b... Inner peripheral surface 3c to 3e First to third seal sliding contact surfaces 4 Drive shaft 5 Cam ring (movable member) 5c to 5e Seal component (projection) 6 Rotor (pump component) ), 7... Vane (pump structure), 9... Pivot pin (oscillating fulcrum), 10a to 10c... First to third seal members (sliding contact portion), 11a... Suction port (suction portion), 12a... Discharge Port (discharge portion) 13 Pump chamber 16 Spring housing chamber 16a Restriction surface 21 First control oil chamber 22 Second control oil chamber 23 Coil spring 33 Remaining portion (unprocessed) ), 40... First outer recess, 41... Second outer recess, 42... Third outer recess, 43... Fourth outer recess, P1 to P4... Deepest portion (outermost portion in radial direction) .

Claims (11)

a pump body having a housing recess;
a pump structure that is arranged in the accommodation recess and is rotationally driven to change the volumes of the plurality of pump chambers and discharge the hydraulic fluid sucked from the suction part from the discharge part;
a movable member that accommodates the pump structure therein and swings to vary the amount of volume change of the plurality of pump chambers;
an outer recess that is provided in the housing recess and is recessed radially outward about the rotation axis of the pump component;
A method for manufacturing a variable displacement pump having
a first step of processing the inner peripheral surface and the bottom surface of the outer recess from the axial direction of the pump body;
Among the machined surfaces of the inner peripheral surface and the bottom surface of the outer recess that have been machined in the first step, the inner peripheral surface and the bottom surface of the housing recess are machined from the circumferential direction while avoiding the radially outermost portion. a second step;
A method of manufacturing a variable displacement pump, comprising: In the manufacturing method of the variable displacement pump according to claim 1,
A method of manufacturing a variable displacement pump, wherein the same processing tool is used in the first step and the second step. In the manufacturing method of the variable displacement pump according to claim 1,
A method of manufacturing a variable displacement pump, wherein the machining tool in the first step and the machining tool in the second step are end mills having the same diameter. In the manufacturing method of the variable displacement pump according to claim 1,
The movable member includes an annular main body that accommodates the pump structure therein, and protrudes radially outward from the outer periphery of the main body, enters the outer concave portion, and extends to the inner peripheral surface of the outer concave portion. and a projecting portion having a sliding contact portion that is in sliding contact with a portion of the variable displacement pump. In the method for manufacturing a variable displacement pump according to claim 4,
On the bottom surface of the outer recess, between the processed surface formed in the first step and the processed surface formed in the second step, a projecting shape that is not processed in the first step and the second step is provided. 1. A method of manufacturing a variable displacement pump, characterized by having a machining residue. In the method for manufacturing a variable displacement pump according to claim 5,
A method of manufacturing a variable displacement pump, wherein the machining residue is formed at a position that does not abut against the protrusion in the axial direction within the swinging range of the movable member. In the method for manufacturing a variable displacement pump according to claim 5,
The sliding contact portion is a sealing member that slides on the inner peripheral surface of the housing recess, and the projecting portion of the movable member has a sealing recess into which the sealing member is received,
A method of manufacturing a variable displacement pump, wherein the unprocessed portion is located at a position where it does not come into contact with the seal member in the axial direction within the swinging range of the movable member. In the manufacturing method of the variable displacement pump according to claim 1,
A method of manufacturing a variable displacement pump, wherein a plurality of said outer recessed portions are formed on the inner peripheral surface of said accommodating recessed portion. a pump body having a housing recess;
a pump structure that is arranged in the accommodation recess and is rotationally driven to change the volumes of the plurality of pump chambers and discharge the hydraulic fluid sucked from the suction part from the discharge part;
A ring-shaped main body that accommodates the pump structure therein, and a protruding portion that protrudes radially outward from the outer periphery of the main body and has a sliding contact portion that is in sliding contact with the accommodating recess, and is swung. a movable member that varies the volume change amount of the plurality of pump chambers by
an outer recess that is provided on the inner peripheral surface of the housing recess, is recessed radially outward about the rotation axis of the pump assembly, and is capable of receiving the protrusion;
A variable displacement pump comprising
The outer recess has a first processed surface that is a processed surface of the bottom surface and the inner peripheral surface of the outer recess,
The housing recess has a second processed surface that is a processed surface of the bottom surface and the inner peripheral surface of the housing recess,
A variable displacement pump, wherein a machining residue is formed between the bottom surface of the first machined surface of the outer recess and the bottom surface of the second machined surface of the housing recess. In the variable displacement pump according to claim 9,
The variable displacement pump according to claim 1, wherein the unprocessed portion is formed at a position that does not axially abut against the protrusion within a swinging range of the movable member. In the variable displacement pump according to claim 10,
The sliding contact portion is configured by a sealing member that is in sliding contact with the inner peripheral surface of the outer concave portion,
the projecting portion of the movable member has a sealing recess in which the sealing member is held on the outer surface;
The variable displacement pump according to claim 1, wherein the unprocessed portion is formed at a position that does not abut against the seal member in the axial direction within the swinging range of the movable member.

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