JP2009008062A - Water pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water pump for cooling an engine capable of improving transfer efficiency of cooling water with an extremely simple structure. <P>SOLUTION: The water pump has an impeller 4 radially formed with a plurality of blade pieces 43 and formed with a ring shaped front plate 44 at top ends of the blade pieces 43, and a blade piece storage chamber 12 storing the blade pieces 43 of the impeller 4 inside with a proper clearance c left from the front plate 44. A suction chamber 11 communicating with a suction port 15 is formed at a central portion of the impeller 4, and the water pump comprises a housing 1 in which a pump discharge port 1 is situated at a position corresponding to a side of the impeller 4 where the blade pieces 43 are formed and to its outer peripheral side. A circumferential projection 13 projecting toward a blade piece 43 side is formed at a boundary between the blade piece storage chamber 12 and the suction chamber 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water pump for cooling an engine that can improve the efficiency of cooling water transfer with a very simple structure.

Water pumps that circulate cooling water in automobile engines are often used. In general, in a centrifugal pump such as a water pump, when the impeller rotates, impingement of the cooling water on the blades imparts centrifugal force to the cooling water, and the impeller moves in the centrifugal direction. When the discharge port is installed in the centrifugal direction, the cooling water can flow out through the discharge port. In such a water pump, in order to prevent the impeller from interfering with a counterpart member such as an engine block to prevent the impeller from rotating, there is a slight gap between the impeller and the counterpart member. It is necessary to provide clearance.
JP-A-4-362297

  However, the cooling water that has flown through the clearance between the impeller blades and the mating member is a region where centrifugal force (energy) is not applied no matter how much the impeller rotates. That is, the impeller is an area where work cannot be given to the cooling water. Then, since the pressure on the suction side is lower than the discharge side of the pump housing, a phenomenon that the cooling water once moved to the discharge side flows back to the suction side through the clearance portion occurs.

  Generally, the smaller the clearance, the higher the efficiency and the greater the flow rate. However, if the clearance is too small, the impeller will not rotate due to interference with the mating member. Is generally designed with a certain size. Therefore, Patent Document 1 discloses that the reverse flow of the cooling water is reduced by setting the clearance area longer, rather than setting the clearance size smaller. By the above means, the backflow of the cooling water in the clearance portion can be reduced, and the efficiency and flow rate can be improved.

  However, the method according to Patent Document 1 has the following problems. First, since the suction diameter is reduced by the impeller guide portion, the flow velocity increases there, and cavitation is likely to occur. Next, since a minute clearance region with the counterpart member is a considerably wide region from the outer diameter portion of the impeller to the front end of the guide portion, a considerably strict manufacturing accuracy is required. If manufacturing control is not performed strictly in this way, any part of the impeller will be rubbed with the mating member, leading to fatigue failure of the impeller.

  In addition, if the impeller is made of resin, the resin material is greatly deformed by thermal expansion, so it is not possible to reduce the clearance for safety reasons. Therefore, the cooling water flows backward and the efficiency when the cooling water is hot is high. There was a limit to improvement. Furthermore, in order to maintain the flow rate, it is necessary to smoothly change the cross-sectional area of the flow path, and thus the thickness of the tip of the guide portion must be reduced. If such a structure is not used, water will collide with the side surface (front end lateral surface) of the guide portion, and the efficiency and flow rate will decrease.

  However, for this reason, the mechanical strength of the guide portion is lowered. Also, when it is made of synthetic resin, if it is submerged in high-temperature cooling water, it swells (swells by sucking cooling water), thermal deformation is unavoidable, and it appears more in thin parts, The tip of the guide was a weak point. An object of the present invention is to provide a water pump that can maintain good pump efficiency and flow rate in the water pump and that does not require manufacturing costs while maintaining its mechanical strength.

  In view of the above, the inventor has intensively and researched to solve the above problems. As a result, the invention of claim 1 is formed in such a manner that a plurality of blade plate pieces are radially formed, and the front end of the blade plate piece has a ring-shaped front. An impeller having a plate formed therein, a blade plate storage chamber for storing a blade plate piece of the impeller having an appropriate clearance with the front plate inside, and communicating with a suction port at a central portion of the impeller A suction chamber is formed, and includes a housing in which a pump discharge port is located at a position corresponding to the blade plate forming side and the outer peripheral side of the impeller, and the blade plate one side is located at the boundary between the blade plate piece storage chamber and the suction chamber. The above-mentioned problem has been solved by providing a water pump in which a circumferential protrusion protruding toward the surface is formed.

  According to a second aspect of the present invention, in the configuration described above, the front plate is formed to be inclined so as to gradually become lower from the front edge side in the rotation direction of the blade plate piece toward the rear edge side in the rotation direction, and the blade plate piece storage chamber. The above-mentioned problem has been solved by providing a water pump having a clearance portion on the inner peripheral side wall surface as an inclined surface along the outer surface side of the front plate. According to a third aspect of the present invention, there is provided the water pump according to the above-described configuration, wherein the tip position of the circumferential protrusion is set to be substantially the same as the inner surface side of the front plate of the impeller. Solved.

  According to a fourth aspect of the present invention, there is provided the water pump according to the above-described configuration, wherein the tip position of the circumferential protrusion is set to be substantially the same as the outer surface side of the front plate of the impeller. Solved.

  According to the invention of claim 1, the pump housing is provided with a blade plate piece storage chamber for storing the impeller blade plate piece and a suction chamber for sucking cooling water, and the blade plate piece storage chamber, the suction chamber, Since a circumferential projection is formed at the border of the blade, the cooling water once entering the blade plate storage chamber by the rotation of the impeller is transferred to the impeller front plate and the blade plate. Even if it flows into the clearance between the one storage chamber (a mating member such as a pump housing), it is blocked by the circumferential protrusion, and the cooling water can be prevented from flowing back into the suction chamber.

  Further, since the backflow of the cooling water is blocked by the circumferential protrusions, the cooling water stays in the clearance area, and the remaining cooling water causes the cooling water to flow further in the clearance area. Intrusion can be prevented, and pump efficiency can be further improved. Further, in the first aspect, as described above, an extremely simple structure in which only a circumferential protrusion protruding toward the blade plate piece side is formed at the boundary between the blade plate piece storage chamber and the suction chamber. Thus, the above-described effects can be achieved, and while having such effects, the manufacturing cost is not required and the apparatus is provided at a low price.

  According to the invention of claim 2, the top portion of the blade plate piece is formed so as to be gradually lowered from the rotation direction front edge side toward the rotation direction rear edge side, and the inner peripheral side wall surface of the blade plate piece storage chamber is By making the water pump as an inclined surface along the top of the blade plate, the clearance area becomes an inclined surface shape, the clearance area becomes longer, and the cooling water is more difficult to flow back together with the circumferential protrusion. Can be. According to the invention of claim 3, the tip position of the circumferential protrusion is set so as to be substantially the same as the inner surface side of the front plate of the impeller, so that even the circumferential protrusion is slightly cooled. Even if water leaks out, the circumferential projection is located on the inner surface side of the front plate, so that centrifugal force is applied by the blade plate piece and fed into the discharge port.

  According to the invention of claim 4, the tip end position of the circumferential projection is set to be substantially the same as the outer surface side of the front plate of the impeller, so that the suction cross-sectional area is secured while preventing backflow. Therefore, good suction is maintained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1, 2, and 3, the pump housing 1 is formed with a suction chamber 11 and a blade piece storage chamber 12. The suction chamber 11 is a portion in which a blade plate 43 of the impeller 4 described later is accommodated. Specifically, it is a portion that can be accommodated so as to cover the outer periphery and the top portion of the blade base portion 42, the blade plate piece 43, and the front plate 44 of the blade plate piece 43. The suction chamber 11 is located at the center of the impeller 4, communicates with the suction port 15, and the vane plate piece storage chamber 12 communicates with the discharge port 16. Further, the discharge port 16 is located on the side where the blade plate 43 of the impeller 4 is formed and on the outer peripheral side.

  The vane piece housing chamber 12 is formed with a side surface facing the front plate 44 of the impeller 4, that is, a substantially circumferential inner circumferential side wall surface 121 in which a clearance c is set. Further, the inner peripheral side wall surface 121 is formed in a shape according to the outer shape of the front plate 44 of the impeller 4 as shown in FIGS. 3 (A) and 3 (B). The front plate 44 is a type in which the top portion of the blade plate piece 43 is formed so as to be gradually lowered from the rotation direction front edge 431 toward the rotation direction rear edge 432, that is, in the case of being formed in a flat conical shape, In accordance with the shape, the inner peripheral side wall surface 121 of the blade-plate piece storage chamber 12 is formed as an inclined surface (see FIGS. 1, 2, and 3B).

  The boundary between the suction chamber 11 and the blade piece storage chamber 12 is a corner portion. As shown in FIGS. 1, 2 to 3, etc., a circumferential protrusion 13 is formed at the corner. Is formed. The circumferential protrusion 13 protrudes toward the blade plate 43 side of the impeller 4 and is formed with a protrusion so as to form a circumferential ring. Specifically, the tip of the circumferential protrusion 13 is formed so as to bite toward the blade base part side supporting the blade plate piece 43 along the rotation direction front edge 431 of the blade plate piece 43 of the impeller 4. It is a thing.

  The circumferential protrusion 13 is set so that the position of the tip 131 thereof is the same (including substantially the same) as the inner surface 44b of the front plate 44 of the impeller 4 [FIGS. B), see FIG. Here, when the front plate 44 is formed in a flat conical shape, the position of the tip 131 of the circumferential protrusion 13 is substantially the same as the position of the outer peripheral edge of the front plate 44. Is set.

  As shown in FIGS. 7A and 7B, the impeller 4 is formed with a plurality of blade base portions 42, 42,... Radially around the boss portion 41. A blade plate piece 43 is formed from the end portion. The boss 41 is formed in a cylindrical shape. The vane piece 43 is formed in a substantially trapezoidal shape. The vane plate piece 43 is formed to be bent at a substantially right angle with respect to the vane base portion 42 such that the front edge 431 in the rotation direction is closer to the boss portion 41 side than the rear edge 432 in the rotation direction. It is. The front plate 44 is formed on the top of the blade plate piece 43, and includes an embodiment formed in a flat conical shape (see FIG. 7C) and an embodiment formed as a disc-shaped ring. Exists (see FIG. 7D).

  Further, as another embodiment of the impeller 4, as shown in FIG. 8, the impeller 4 is made of a single metal plate, and a plurality of blade base portions 42 are radially arranged on the same plane around the base circle portion 411. A blade plate 43 having an appropriate inclination angle is formed so that the rotation direction leading edge 431 is positioned on the center side of the rotation direction trailing edge 432, and the blade plate 43 is bent at a substantially right angle. A blade cover piece 441 is bent at a substantially right angle from the end, and the outer end side of each blade cover piece 441 is substantially adjacent to the inner end side of the adjacent blade cover piece 441, and a plurality of blade cover pieces 441, 441, A front plate 44 continuously formed in a substantially ring shape is formed (see FIGS. 8A and 8B).

  In order to assemble the impeller from the original plate, first, the blade plate piece 43 is bent at a right angle with respect to the blade base portion 42 along the first bending imaginary line Ta from the state of FIG. Next, the blade cover piece 441 is bent at a right angle along the second bent virtual line Tb. At this time, the blade cover piece 441 is bent so as to be opposite to the bending direction of the blade base portion 42 and the blade plate piece 43. Specifically, the blade base portion 42, the blade plate piece 43, and the blade cover piece 441 are formed to be bent so as to form a substantially “B” shape (see FIG. 8C).

  The blade base 42, the blade plate piece 43, and the blade cover piece 441 are all bent at a right angle. The outer end side 441b of each blade cover piece 441 is finished so as to be substantially close to the inner end side 441a of the adjacent blade cover piece 441. Actually, the step of forming the impeller 4 from the original plate is performed on one press processing line, and all the blade plate pieces 43 and all the blade cover pieces 441 are bent and formed by pressing substantially in order. Is.

  Further, there is an embodiment in which the outer end side 441b of the blade cover piece 441 is welded to the inner end side 441a of the adjacent blade cover piece 441 by welding means. As a result, the plurality of independent blade cover pieces 441, 441,... Integrally form a single disc-shaped ring, thereby forming the front plate 44 having mechanical strength. . Further, although the impeller 4 is made of metal, the front plate 44 may be constituted by a member different from the blade plate piece 43 and fixed by fixing means such as welding. The structural members such as the boss 41, the blade plate 43, and the front plate 44 may be integrally formed of synthetic resin.

  The rotation direction of the impeller 4 is a direction in which the cooling water is blown out of the impeller 4, and the cooling water is ejected from the trailing edge 432 in the rotation direction of the blade plate piece 43. The front plate 44 is formed as a flat conical ring at the top of the vane piece 43 (see FIGS. 7A and 7C). Alternatively, there is an embodiment in which the front plate 44 is formed as a flat plate-like ring (see FIGS. 6 and 7D). The front plate 44 serves to keep the cooling water in a region where the blade plate pieces 43 give energy to the cooling water. The impeller 4 is mounted on the pump housing 1 with the boss portion 41 via the drive shaft 2 with a bearing. The bearing-equipped drive shaft 2 is waterproofed by a mechanical seal 3 inside the pump housing 1.

  Next, the circumferential protrusion 13 in the present invention will be described. A clearance (gap) c exists between the blade plate piece storage chamber 12 and the front plate 44 of the impeller 4. The area of the clearance c is a range extending from the outer surface side 44a of the front plate 44 of the impeller 4 to the inner peripheral side surface of the outer surface side 44a (the end edge near the rotation direction front edge 431 of the blade plate piece 43). The clearance c may be relatively large. As described above, the circumferential projection 13 is formed at the boundary between the suction chamber 11 and the blade plate piece storage chamber 12.

  The circumferential protrusion 13 is formed so as to bite in the vicinity of the leading edge 431 and the vicinity of the top of each blade plate 43 of the impeller 4 in a close and non-contact state. The position of the tip 131 of the circumferential projection 13 is substantially the same as that of the inner surface 44b of the front plate 44 of the impeller 4 (see FIG. 4), and the tip 131 of the circumferential projection 13. There is a second embodiment in which the position is substantially the same as the outer surface side 44a of the front plate 44 of the impeller 4 (see FIG. 5).

  First, the cooling water sucked into the suction chamber 11 from the suction port 15 is sent to the vane piece storage chamber 12, and most of it is discharged from the discharge port 16. However, a slight amount of the cooling water sent to the discharge port 16 side tends to flow into the clearance c. The cooling water flowing into the clearance c is prevented from flowing into the suction chamber 11 side by the circumferential projection 13.

  Furthermore, since the cooling water that has flowed into the clearance c does not flow into the suction chamber 11, as shown in FIGS. 4 (B) and 5 (A), the cooling water stays in the clearance c. The cooling water staying inside blocks the inflow of further cooling water into the clearance c, and the cooling water can be prevented from flowing back through the clearance c. The flow of the cooling water when the reverse flow of the cooling water is prevented is indicated by arrows in FIGS. 4B and 5. As described above, the backflow of the cooling water is prevented by the circumferential protrusion 13 in the first and second embodiments.

  Further, the position of the tip 131 of the circumferential protrusion 13 of the second embodiment is formed substantially the same as the outer surface side 44a of the front plate 44 of the impeller 4, and the suction cross-sectional area is prevented while preventing backflow. Can also be secured (see FIG. 5).

  As described above, even if the clearance c is formed relatively large by the circumferential protrusion 13, the cooling water can be prevented from flowing backward from the clearance c, or the amount of the backward flow can be kept to a minimum. The pump efficiency can be made extremely good.

It is the side view made into the partial cross section of this invention. FIG. 5 is an enlarged cross-sectional view with a part cut away showing a configuration of a pump housing and an impeller. (A) is Xa-Xa arrow sectional drawing of FIG. 1, (B) is principal part sectional drawing of a pump housing. (A) is a principal part expanded sectional view which shows the circumferential protrusion of 1st Embodiment, (B) is an expanded sectional view which shows the effect | action of (A). It is an expanded sectional view which shows the circumferential protrusion of 2nd Embodiment, and its effect | action. It is an expanded sectional view of embodiment with which the impeller which has a flat disk-shaped front plate was mounted | worn. (A) is a perspective view of an impeller, (B) is a cross-sectional view taken along the line Xb-Xb of (A), (C) is a cross-sectional view taken along the line Xc-Xc of (B), and (D) is another embodiment. It is sectional drawing of an impeller. (A) is a perspective view of an impeller integrally formed with a metal original plate, (B) is a plan view of the impeller, (C) is a cross-sectional view taken along the line Xd-Xd of (B), and (D) is a developed view of the impeller. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pump housing, 11 ... Suction chamber, 12 ... Blade board piece storage chamber, 121 ... Inner peripheral side wall surface,
13 ... Circumferential protrusion, 15 ... Suction port, 16 ... Discharge port, 4 ... Impeller,
43 ... blade plate piece, 431 ... rotation direction leading edge, 432 ... rotation direction trailing edge,
44 ... front plate, 44a ... blade cover piece, 44b ... inner surface side, c ... clearance.

Claims (4)

  An impeller having a plurality of blade plate pieces radially formed and a ring-shaped front plate formed at the top end of the blade plate piece, and the blade plate of the impeller having an appropriate clearance with the front plate inside. There is a blade plate storage chamber for storage, a suction chamber communicating with the suction port is formed at the center of the impeller, and a pump discharge port is positioned at a position corresponding to the blade plate formation side and the outer peripheral side of the impeller A water pump comprising a housing, wherein a circumferential protrusion is formed at a boundary between the blade plate piece storage chamber and the suction chamber and protrudes toward the blade plate piece side.   2. The front plate according to claim 1, wherein the front plate is formed to be inclined so as to gradually become lower from the front edge side in the rotation direction of the blade plate piece toward the rear edge side in the rotation direction, and the clearance of the inner peripheral side wall surface of the blade plate piece storage chamber. The location is an inclined surface along the outer surface side of the front plate.   3. The water pump according to claim 1, wherein a tip position of the circumferential projection is set to be substantially the same as an inner surface side of a front plate of the impeller.   3. The water pump according to claim 1, wherein a tip position of the circumferential protrusion is set to be substantially the same as an outer surface side of the front plate of the impeller.

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