JP3672975B2 - Aluminum pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a suction connector in an aluminum pump for connecting a hydraulic oil supply pipe from an external tank and a pump suction port.
[0002]
[Prior art]
A vehicle such as an automobile is equipped with a power steering device using hydraulic pressure, and a vane pump is adopted as a hydraulic pressure supply source. In order to reduce the weight of such a vane pump, the body is cast and molded with a light alloy such as aluminum. As the suction connector for connecting the suction port of the pump and the hydraulic oil supply pipe from the external tank, there are those shown in FIGS.
[0003]
This is because a suction port 104 is formed in the upper surface of the body 107 made of a light alloy such as aluminum in the drawing, and a suction pipe 102 having a flange 101 is fastened to the body 107, so that the suction port 104 and the suction pipe 102 are connected. Is connected to an external hydraulic oil supply pipe.
[0004]
The flange 101 is welded or brazed to the outer periphery of the end of the suction pipe 102, and the bolt 118 penetrating the flange 101 is screwed into a bolt hole 116 formed in the body 107, whereby the suction pipe 102 is coupled to the body 107. The
[0005]
A seal groove 120 is formed around the suction port 104 in the body 107 facing the flange 101, and a joint between the suction pipe 102 and the suction port 104 is sealed by a seal member 119 interposed in the seal groove 120. Stopped, preventing leakage of hydraulic fluid.
[0006]
This pump constitutes a vane pump in which a pump cartridge 103 composed of a rotor, a vane, and a cam ring is housed in a body 107 and a cover 106, and hydraulic oil discharged from the pump cartridge 103 by rotating the drive shaft 110 Is guided to the flow control valve 105 from a high pressure chamber 111 formed by the side plate 108 and the body 107 through a passage (not shown), and only a required flow rate is supplied to the power steering device, while an excessive flow rate is a suction port 104. Together with the hydraulic oil from the bypass passage 109 through the passage 112 formed inside the cover 106 and sucked into the pump cartridge 103.
[0007]
Further, as disclosed in Japanese Patent Publication No. 61-46668, a suction port is mechanically formed in a cast molded body, and the suction port is threaded to provide a hydraulic oil supply pipe from outside. Also known are screwed connections.
[0008]
[Problems to be solved by the invention]
However, in the former conventional example, since the suction pipe 102 and the flange 101 are joined by welding, there is a problem in that, in addition to an increase in the number of processing steps, oil leakage occurs depending on poor welding or poor brazing. During welding or brazing, a scale (metal oxide film) is formed on the flange 101 and the suction pipe 102 by heating, and a post-treatment step such as pickling is required to remove the scale. Corrosion may occur in the flange 101 and the suction pipe 102, and it is difficult to stabilize the quality. In addition to the assembly of the flange 101 and the suction pipe 102, processing of the seal groove 120 and a seal member 119 are required. As a result, the number of parts and the number of processing steps increase, resulting in increased manufacturing costs Which was.
[0009]
Further, in the latter conventional example, since the threading process is performed after the suction port is mechanically perforated, there is a problem that the manufacturing cost increases correspondingly.
[0010]
Therefore, an object of the present invention is to provide an aluminum pump that can reduce the manufacturing cost by eliminating the machining after casting.
[0011]
[Means for Solving the Problems]
A first aspect of the present invention is an aluminum pump body provided with a shaft hole of a drive shaft that couples a rotor of a pump cartridge to one end, and a suction for connecting piping for introducing hydraulic oil from a tank into the pump cartridge in the pump body. In an aluminum pump in which a connector projects from the pump body, the suction connector is disposed so as to be positioned in a plane perpendicular to the drive shaft, and is cast into aluminum integrally with the pump body. A suction passage connected to the inside of the pump body is formed by a core pin or a core hole in the aluminum casting.
[0012]
Further, a second invention is the above-mentioned first invention, wherein the suction passage and the drain hole extending from the lower end thereof toward the drive shaft hole inside the pump body are arranged at the time of the aluminum casting molding. It is formed by a cored pin or stepped core hole.
[0013]
[Action]
Therefore, when molding the pump body by casting aluminum die casting or the like, the core pin or core that forms the suction passage of the suction connector part is placed in a plane that is orthogonal to the axis of the shaft hole of the drive shaft. As a result, it is possible to perform die-cutting at the time of casting without any hindrance, and it is possible to directly use a punching hole such as a casting pin at the time of casting as a suction passage, and the suction passage formed on the inner periphery of the suction connector It can be used as it is as a hydraulic oil passage without machining.
[0014]
Embodiment
1 to 4 show an embodiment when the present invention is applied to a vane pump.
[0015]
1 to 4, reference numeral 1 denotes a body of a vane pump that supports a drive shaft 9 and accommodates a flow control valve 5, and this body 1 includes a cam ring 8 and the like in which a rotor 6 is rotatably accommodated. A cover 2 serving as a second body for housing the pump cartridge 3 and the side plate 4 is coupled, and the pump cartridge 3 includes, for example, a vane 7, a rotor 6, a cam ring 8, and the like.
[0016]
A drive shaft 9 is pivotally supported via a bearing metal 16 disposed in a shaft hole 17 penetrating substantially the center of the body 1, and a hydraulic pressure (not shown) is applied to the suction connector 10 that is integrally cast from the top of the body 1. Piping is joined. A pulley or the like (not shown) is coupled to the right end of the drive shaft 9 in the drawing.
[0017]
A flow control valve 5 is housed inside the body 1, and hydraulic oil whose flow rate is adjusted is pumped from the discharge port 5 </ b> A shown in FIGS. 2 and 3 to the outside of the vane pump.
[0018]
As shown in FIG. 1, the pump cartridge 3 is in contact with the end surface 1A of the body 1 facing the cover 2, and the cam ring 8 constituting the pump cartridge 3 is engaged with the bottom of the cover 2 formed in a concave shape. The disc-shaped side plate 4 is sandwiched between the end surface 1A.
[0019]
Here, the pumping area in the pump cartridge 3 is composed of a rotor 6 splined to the drive shaft 9 on the inner periphery of the cam ring 8 and a vane 7 supported by the rotor 6 and in sliding contact with the inner periphery of the cam ring 8. As shown in FIG. 2, the inner periphery of 8 communicates with suction ports 14 and 14 and discharge ports 15 and 15 formed on the end surface 1A of the body 1 facing the pump cartridge 3 in a predetermined phase.
[0020]
On the other hand, the hydraulic oil passage formed in the body 1 has a suction passage 11 formed in a substantially vertical direction in a plane orthogonal to the axis of the drive shaft 9 in FIGS. 1 and 4 from the inner peripheral portion of the suction connector 10. The suction passage 11 is formed toward the inside of the body 1, and the lower portion of the suction passage 11 communicates with a suction communication passage 12 that is disposed in a substantially horizontal direction in the drawing and opens to the end face 1 </ b> A. Is connected to the bypass side for discharging the excessive flow rate of the flow control valve 5, and hydraulic oil flows into the inner periphery of the cover 2 from the suction communication passage 12 opened in the end face 1 </ b> A.
[0021]
As shown in FIG. 2, a pair of suction ports 14, 14 are bifurcated across the drive shaft 9 and formed in a concave shape at a predetermined depth on the end surface 1 </ b> A. 12 are formed at a predetermined depth so as to surround the upper semicircular outer peripheral portion of the outer periphery of the cam ring 8.
[0022]
The groove portions 12A and 12B operate from the suction communication passage 12 opened to the end surface 1A to the suction ports 14 and 14 by forming a gap between the end surface 1A of the cam ring 8 and the end surface 1A of the body 1 in the pump cartridge 3 in contact with each other. A bifurcated low-pressure distribution passage for supplying oil is formed.
[0023]
The discharge region of the cam ring 8 is a predetermined position determined by a confined space formed by housing the rotor 6 on the inner surface of the cam ring 8 and the rotational direction of the rotor 6, as shown in FIGS. In addition, a pair of discharge ports 15, 15 opened in the vertical direction in the figure on the end face of the body 1 across the drive shaft 9 are opposed to and communicate with each other, and these discharge ports 15, 15 are annular formed inside the body 1. The communication fluid 19 communicates with the flow control valve 5 via the discharge passage 13, and the pressure oil whose excess flow rate is adjusted by the flow control valve 5 is pumped from the discharge port 5A shown in FIG. 4 to the outside. Is done.
[0024]
Here, the body 1 is formed by casting a light alloy such as aluminum by die casting or the like, and at the time of molding, the suction connector 10 is directed upward in a plane perpendicular to the axis of the drive shaft 9 from the upper part of the body 1 in the figure. Are integrally formed in a projecting manner.
[0025]
The suction connector 10 protrudes from the upper part of the body 1 at a predetermined height and is connected to a hydraulic oil supply pipe of a power steering device (not shown).
[0026]
The suction passage 11 in the suction connector 10 is simultaneously formed by a cast pin or a movable core when the aluminum body 1 is cast, and a cast hole such as the cast pin is used as it is as a passage. .
[0027]
An oil seal 18 is provided on the end surface of the shaft hole 17 from which the drive shaft 9 projects, and the drain groove 50 is driven from the end surface of the shaft hole 17 toward the end surface 1A as shown in FIGS. It is formed with a predetermined depth parallel to the axis of the shaft 9.
[0028]
The drain groove 50 is formed from the end face of the shaft hole 17 to at least directly below the suction passage 11, and a drain passage 51 is formed between the suction passage 11 and the drain groove 50 in a plane perpendicular to the axis of the drive shaft 9. The drain passage 51 is linearly arranged on the extension of the suction passage 11. Further, the inner diameter of the drain passage 51 is formed smaller than the inner diameter of the suction passage 11, and the drain passage 51 is formed simultaneously with the suction passage 11 at the time of casting by a punch hole such as a stepped cast pin.
[0029]
It is comprised as mentioned above, Next, an effect | action is demonstrated.
[0030]
When the rotor 6 of the pump cartridge 3 is driven by the rotation of the drive shaft 9, the hydraulic oil in the suction passage 11 of the suction connector 10 is separated by assembling each part inside the cover 2 via the suction communication passage 12. It flows into the suction passage 20 as a low-pressure channel formed.
[0031]
The pump cartridge 3 including the vane 7, the rotor 6, the cam ring 8, and the like sucks the hydraulic oil through the suction ports 14 formed between the body 1 and the side plate 4, and is hydraulically pumped from the discharge port 15. Is guided to the flow control valve 5 through the communication passage 19 and the discharge passage 13 inside the body 1, and only the necessary flow rate is supplied from the discharge port 5A, and the surplus flow rate is returned to the suction communication passage 12, and the suction connector 10. And the hydraulic oil in the suction passage 11 flows into the suction passage 20.
[0032]
On the other hand, the hydraulic fluid leaking from the pump cartridge 3 flows into the drain groove 50 formed along the shaft hole 17 from the gap between the drive shaft 9 and the bearing metal 16, and further drained from the drain groove 50 in the vertical direction. The refrigerant recirculates to the suction communication passage 12 through the passage 51 and the suction passage 11 and is again sucked into the pump cartridge 3 so that the back pressure applied to the oil seal 18 can be released to the suction side.
[0033]
Here, the body 1 is formed of a light alloy such as aluminum by casting such as die casting, but the drain passage 51 and the suction passage 11 are disposed so as to be located in a plane orthogonal to the shaft hole 17 of the drive shaft 9. At the same time, since the drain passage 51 is formed on the extension of the suction passage 11, the drain passage 51 and the suction passage 11 can be simultaneously formed by, for example, a punched hole of a stepped core pin during the casting.
[0034]
That is, as shown in FIG. 5, reference numeral 160 denotes a stepped core pin (or a movable core) configured to protrude to the inner periphery of a die (not shown) to form the suction passage 11 and the drain passage 51, On the other hand, the resin core (or core pin) 150 is a cylindrical member corresponding to the shape of the shaft hole 17 and a convex portion 151 corresponding to the drain groove 50 is provided on the outer periphery along the axis.
[0035]
The cylindrical cast pin 160 extends a small diameter portion 160B that forms the drain passage 51 on the extension of the large diameter portion 160A that forms the suction passage 11, and the casting pin 160 is inserted into the shaft hole during casting. In the state in which the end of the small-diameter portion 160B is in contact with the convex portion 151 of the molding core 150 of the shaft hole 17 while projecting to the inner periphery of the die so as to be substantially orthogonal to the molding resin core 150 of the molding 17. Inject molten metal into the mold. And in the case of mold release, it can cast smoothly by retracting the casting pin 160 with a casting_mold | template.
[0036]
Thus, the suction connector 10 protrudes from the body 1 and is integrally formed, and the suction passage 11 and the drain passage 51 on the inner periphery are cast by the casting pin and are formed by the punched hole. The punched hole can be used as it is as the suction passage 11 without performing the process, and the number of parts and the number of processing steps can be greatly reduced as compared with the conventional example, and the manufacturing cost can be reduced, and the product quality can be stabilized. This makes it possible to improve reliability.
[0037]
FIG. 6 shows a second embodiment, and shows a case where the present invention is applied to the vane pump shown in FIGS. 7 and 8 of the conventional example, and is orthogonal to the axis of the drive shaft 110 as in the first embodiment. The suction connector 10A is integrally projected from the upper surface in the drawing of the body 107, and the suction passage 104 on the inner periphery of the suction connector 10A is formed so as to use a punched hole such as a cast pin. Similarly to the above, it is possible to realize a reduction in manufacturing cost by eliminating the need for machining after casting.
[0038]
【The invention's effect】
As described above, according to the present invention, when the pump body is formed by casting aluminum die casting or the like, the core pin for forming the suction connector is disposed so as to be located in a plane orthogonal to the axis of the drive shaft. Therefore, it is possible to perform die cutting at the time of casting without any hindrance, and the suction passage formed by the punching hole of the casting pin on the inner periphery of the suction connector is directly applied to the hydraulic oil passage without being machined after casting. Compared to the conventional example, the number of parts and the number of processing steps can be greatly reduced to reduce the manufacturing cost, and the product quality can be stabilized and the reliability can be improved. Is also possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a vane pump showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG.
FIG. 3 is a side view of the body.
4 is a cross-sectional view taken along the line BB in FIG. 3;
FIG. 5 is a perspective view of a core pin.
FIG. 6 is a cross-sectional view of a vane pump showing a second embodiment.
FIG. 7 is a sectional view of a vane pump showing a conventional example.
FIG. 8 is an enlarged view of the suction connector.
[Explanation of symbols]
1 Body 9 Drive shaft 10 Suction connector 11 Suction passage 17 Shaft hole

Claims (2)

An aluminum pump body with a shaft hole in the drive shaft that couples the rotor of the pump cartridge to one end, and a suction connector for connecting the piping that introduces hydraulic oil from the tank to the pump cartridge in the pump body project into the pump body. In the aluminum pump to be installed, the suction connector is disposed so as to be located in a plane orthogonal to the drive shaft, and is casted integrally with the pump body, and the suction connector portion is connected to the pump body. An aluminum pump characterized in that the passage is formed by a core pin or a core hole in the aluminum casting. The suction passage and the drain hole extending from the lower end toward the drive shaft hole inside the pump body are formed by a stepped core pin or a stepped core punch hole at the time of the aluminum casting. The aluminum pump according to claim 1.

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