The present invention relates to a pump end plate manufacturing method and a pump.
A housing of a vane pump of Patent Document 1 has a housing body with a bottomed cylindrical shape and an end plate that seals an opening portion of the housing body. A manufacturing method of an end plate includes a punching step and a polishing step. In the punching step, a workpiece that becomes the end plate is manufactured by punching a plate material. A sag is formed in a cutting surface of the workpiece after the punching step. If the workpiece is used as the end plate with the sag still remaining, sealability of a mating surface (sealing interface) between the end plate and the opening portion of the housing body will deteriorate. Thus, in the polishing step which is after the punching step, the sag is removed by polishing an inner surface (surface on the mating surface side) of the workpiece.
Patent Document 1: Japanese Patent Application Publication No. 2009-7951 (JP 2009-7951 A)
However, in the polishing step, the workpiece needs to be polished from the cut end surface to a portion that has no sag. Thus, the polishing step is complex. An object of the present invention therefore is to provide a manufacturing method of an end plate of a pump that can easily remove the sag. Additionally, an object of the present invention is to provide the pump in which sealability of the mating surface is easily ensured.
In order to solve the above problem, a manufacturing method of an end plate of a pump of the present invention is a manufacturing method of an end plate of a pump including a punching step of punching a workpiece from a plate material, the workpiece being the end plate that has a mounting seat in which a fastener is inserted. The method is characterized by including a pressing step of forming a pressed trace surface by pressing an outer edge of an outer surface, when a surface, of both front and back surfaces of the punched workpiece, that is further from a sag that is formed on a cut end surface is the outer surface, and a surface, of both front and back surfaces of the punched workpiece, that is nearer to the sag is an inner surface. A section of the pressed trace surface which is disposed along an outer edge of the mounting seat is a fastening section. A section of the pressed trace surface which is other than the fastening section is a non-fastening section. A radial width of the fastening section is shorter than a radial width of the non-fastening section.
Additionally, a pump of the present invention is characterized by including: a cylindrical housing body that includes an opening portion in at least one end in an axial direction; and an end plate which has an inner surface that seals the opening portion, an outer surface that is disposed on the opposite side of the inner surface in the axial direction, and a pressed trace surface that is disposed along an outer edge of the outer surface. The pump has a housing in which a pump chamber is defined.
In the manufacturing method of an end plate of a pump of the present invention, a sag can easily be removed by deforming the material of the workpiece near the cut end surface, when the pressed trace surface is formed in the pressing step. Additionally, the radial width of the fastening section is shorter than the radial width of the non-fastening section. Thus, a bearing surface of the fastener is easily ensured on the mounting seat. Additionally, the material of the workpiece can be sufficiently deformed since the radial width of the non-fastening section is long. Thus, the sag can be reliably removed.
Additionally, in the pump of the present invention, the sag hardly remains on the outer edge of the inner surface of the end plate. Thus, sealability of the mating surface (sealing interface) between the inner surface of the end plate and the opening portion of the housing body is easily ensured.
An embodiment of a manufacturing method of an end plate of a pump of the present invention (hereinafter referred to as “the manufacturing method of an end plate”) and a pump will be described below.
<Configuration of Vane Pump>
First, the configuration of the vane pump of the present embodiment will be described. A vane pump 1 is coupled to a booster (not shown) of a braking system. The vane pump 1 is included in the concept of the “pump” of the present invention. The vane pump 1 is a negative pressure source of the booster. The vane pump 1 has a housing 2, a rotor 3, and a vane 4.
Hereafter, the axial direction (front-rear direction) means the axial direction of the housing 2. The circumferential direction means the circumferential direction that has the center O of an ellipse as the center when viewed in the axial direction of the housing 2. The radial direction means the radial direction that has the center O of the ellipse as the center when viewed in the axial direction of the housing 2.
[Housing 2]
The housing 2 is fixed to a side surface of an engine (not shown). The housing 2 has a housing body 20, an end plate 21, and a pump chamber A. The housing body 20 has a bottomed elliptic cylindrical shape. The housing body 20 has a peripheral wall portion 200, a bottom wall portion 201, and an opening portion 202.
The peripheral wall portion 200 has an elliptic cylindrical shape. The bottom wall portion 201 is disposed in the rear end of the peripheral wall portion 200. An exhaust hole 201d is opened in the bottom wall portion 201.
The opening portion 202 is formed in the front end of the peripheral wall portion 200. The opening portion 202 has a groove 202a, and a plurality of mounting seats 202b. The groove 202a has a ring shape. The groove 202a is formed in the front end surface of the opening portion 202 so as to extend inwardly. A rubber sealing member 92 is housed in the groove 202a. The sealing member 92 is an O-ring.
The mounting seats 202b are disposed in the radial outer side of the groove 202a. The mounting seats 202b are disposed at prescribed intervals in the circumferential direction along the rim of the opening portion 202. An insertion hole 202c is formed in the mounting seat 202b. The insertion hole 202c extends though the mounting seat 202b in the front-rear direction.
The end plate 21 has an elliptic plate shape. The end plate 21 seals the opening portion 202. The end plate 21 has an outer surface (front surface) 210, an inner surface (rear surface) 211, a pressed trace surface 212, and a plurality of mounting seats 213.
The mounting seats 213 are disposed at prescribed intervals in the circumferential direction along the outer edge of the end plate 21. An insertion hole 213a is formed in the mounting seat 213. The insertion hole 213a extends through the mounting seat 213 in the front-rear direction. The insertion hole 213a and the insertion hole 202c are arranged side by side in the front-rear direction. A bolt 90 passes through the insertion hole 213a and the insertion hole 202c in the front-rear direction. The bolt 90 is included in the concept of a “fastener” of the present invention. A nut 91 is screwed to the rear end (passing-through end) of the bolt. The end plate 21 is fixed to the opening portion 202 by the plurality of bolts 90 and the plurality of nuts 91 in this way. Additionally, the elastically deformed sealing member 92 is interposed between the end plate 21 and the opening portion 202.
As shown by the hatching in
The pressed trace surface 212 is defined into a plurality of fastening sections 212a and a plurality of non-fastening sections 212b. The fastening section 212a is disposed along the outer edge of the mounting seat 213. The non-fastening section 212b is disposed along the outer edge of the portion other than the mounting seat 213. As shown in
[Rotor 3, Vane 4]
The rotor 3 has a rotor body 30 and a shaft portion 31. The rotor body 30 is housed in the pump chamber A. The rotor body 30 has a pair of rotor grooves 300a. The rotor grooves 300a are disposed facing each other in the diameter direction, that is, disposed at 180 degrees from each other. The rotor grooves 300a extend through the rotor body 30 in the diameter direction.
The shaft portion 31 is continued rearward from the rotor body 30. The shaft portion 31 extends through the bottom wall portion 201 in the front-rear direction. The shaft portion 31 is coupled to a camshaft (not shown) of an engine via a coupling (not shown) and an oil supply joint (not shown). The shaft portion 31 is rotatable around its axis. Thus, the rotor 3 is rotatable around the axis of the shaft portion 31.
The vane 4 has a vane body 40 and a pair of caps 41. The vane body 40 is housed in the pump chamber A. The vane body 40 is rotatable with the rotor 3. The vane body 40 can move reciprocally in the diameter direction along the rotor grooves 300a. The vane body 40 can define the pump chamber A into a plurality of operation chambers, according to the rotation angle. The caps 41 are disposed on both ends of the vane body 40 in the diameter direction. The cap 41 is in sliding contact with the inner peripheral surface of the peripheral wall portion 200.
As the vane 4 rotates, the volume of each of the operation chambers of the pump chamber A increases or decreases. At this time, the vane pump 1 draws air into the operation chamber from the booster via the intake cylinder 93. The vane pump 1 also exhausts air to the outside from the operation chamber via the exhaust hole 201d.
<Manufacturing Method of End Plate of Vane Pump>
Next, the manufacturing method of an end plate of a vane pump of the present embodiment will be described. The manufacturing method includes a punching step and a pressing step.
[Punching Step]
As shown in
[Pressing Step]
This step includes a workpiece arrangement step and a filling step.
The pressing member 60 is accessible to the recessed portion 610 from above. The shape of a lower surface (pressing surface) 600 of the pressing member 60 is the same as the shape of the end plate 21 seen from the front side as shown in
The flat surface portion 601 has a flat surface. A prescribed uneven pattern (knurled pattern, not shown) is disposed on the flat surface portion 601. The protruded portion 603 is protruded downward along the outer edge of the flat surface portion 601. A pressed trace surface forming portion 602 is provided on the inner peripheral surface of the protruded portion 603 (inclined surface to the flat surface portion 601). The pressed trace surface forming portion 602 has a planar chamfered shape. The pressed trace surface forming portion 602 has a surface tapered upwards. That is, the pressed trace surface forming portion 602 and the pressed trace surface 212 shown in
An outer surface (upper surface) 210a of the workpiece W corresponds to the outer surface 210 of the end plate 21 shown in
In the recessed portion 610 in which the workpiece W is already housed, the gap G is ensured only between the sag F and the corner portion E. Thus, as shown by an arrow Y2 in
<Operation and Effects>
Next, the operation and effects of the manufacturing method of an end plate and a vane pump of the present embodiment will be described. As shown in
As shown in
If the sag remains in the outer edge of the inner surface 211 of the end plate 21, the sealing member 92 needs to be shifted to the radial inner side in order to avoid interference of the sag with the sealing member 92. The capacity of the pump chamber A will therefore decrease. However, in the vane pump 1 of the present embodiment, the sag hardly remains on the outer edge of the inner surface 211 of the end plate 21. Thus, there is no need to avoid interference of the sag with the sealing member 92. Therefore, the capacity of the pump chamber A can be increased. In other words, compared to the vane pump in which the sag remains on the outer edge of the inner surface 211 of the end plate 21, it is possible to ensure a pump chamber A that has the same capacity, in a smaller vane pump 1.
As shown in
As shown in
As shown in
Additionally, in the manufacturing method of the end plate 21 of the present embodiment, even if a flash (burr) occurs on the outer edge of the outer surface 210a of the workpiece W in the punching step shown in
<Others>
The manufacturing method of an end plate of a pump of the present invention and the embodiment of the pump have been described. However, the embodiment is not specifically limited to the embodiment described above. Various modified and improved configurations that a person skilled in the art is capable of carrying out, may be implemented.
The shape of the pressed trace surface forming portion 602 and the pressed trace surface 212 are not particularly limited to the embodiments described above. The pressed trace surface forming portion 602 and the pressed trace surface 212 may be a planar chamfered shape, a round chamfered shape, or a flat surface. The inclination of the pressed trace surface forming portion 602 to the flat surface portion 601 and the inclination of the pressed trace surface 212 to the outer surface 210 are not particularly limited to the embodiments described above. For example, the inclination may be 30°, 45°, or 60°.
In the punching step shown in
The position that the sag F occurs in the punching step (for example, near the portion D that abuts on the rim of the punch insertion hole 510 shown in
For example, the sag F may occur in at least one of the outer edge of the outer surface 210a and the outer edge of the inner surface 211a of the workpiece W shown in
In the pressing step (workpiece arrangement step and filling step) shown in
The pressing step shown in
In the case when the opening portion 202 of the housing body 20 is manufactured by shearing, the pressed trace surface 212 may be formed on the outer edge of the rear surface of the opening portion 202 shown in
The uneven pattern disposed on the flat surface portion 601 of the lower surface 600 of the pressing member 60 is not particularly limited to the embodiments described above. An appropriate uneven pattern may be disposed with the removal of the residual stress of the end plate 21 and the improvement of strength in mind. The flat surface portion 601 may have a flat surface that does not have an uneven pattern. In this way, the flatness of the outer surface 210 of the end plate 21 is improved.
The type of the pump of the present invention is not particularly limited to the embodiments described above. The pump may be a piston pump, a plunger pump, a diaphragm pump, or a rotary pump (a vane pump 1, a gear pump, or a screw pump). A compressor is also included in the pump. Thus, the pump chamber A which requires air-tightness and fluid-tightness may be defined in the housing 2 of the pump.
Number | Date | Country | Kind |
---|---|---|---|
2016-034110 | Feb 2016 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2017/003412 | 1/31/2017 | WO | 00 |