JPWO2015040973A1 - Water pump - Google Patents

Abstract

Provided is a water pump capable of reducing the size of a pump housing including a main impeller and a sub impeller. A pump housing 2 in which a pump chamber 3 is formed inside a front end on the cylinder block 01 side, a drive shaft 6 which is rotatably provided inside the pump housing and in which a pulley 4 is provided on a large diameter shaft portion 6a; A main impeller 7 disposed in the pump chamber, provided on the small-diameter shaft portion 6c of the drive shaft so as to be relatively rotatable via a bearing portion 15 and a driven ring 16, and intermittently connected to the drive shaft by a clutch spring 20. A sub-impeller 32 is provided at a position spaced apart from the main impeller at the tip of the small-diameter shaft portion in the axial direction, and the sub-impeller is disposed inside the introduction passage 03 communicating with the pump chamber from the axial direction.

Description

  The present invention relates to a water pump that is used, for example, to supply cooling water for cooling an engine to the inside of the engine.

  As a conventional water pump, one used in a cooling device for an internal combustion engine described in Patent Document 1 below is known.

  Describing the outline, a drive shaft that is rotatably supported in a pump housing, a main impeller integrally formed at the tip of the drive shaft, and a secondary shaft that is fitted to the drive shaft so as to be relatively rotatable. An impeller is interposed between the main impeller and the sub impeller, and connects the main impeller and the sub impeller when the temperature is equal to or higher than a predetermined temperature, while the sub impeller is connected to the main impeller when the temperature is lower than the predetermined temperature. A clutch mechanism for separating.

  That is, for example, the clutch mechanism cuts off the connection between the main impeller and the sub impeller for a certain time after the low temperature start of the internal combustion engine to improve the warm-up performance, and connects the main impeller and the sub impeller after the warm-up is completed. Then, cooling of the engine is started.

JP-A-7-317688

  However, in the conventional water pump, the outer diameter of the main impeller is increased and the pump chamber is also inevitably arranged because the sub impeller is arranged in the radial direction so that the main impeller is held inside. Will increase in the radial direction. As a result, the outer diameter of the pump housing is increased, and the water pump as a whole must be enlarged.

  The present invention was devised in view of the actual situation of the conventional water pump, and aims to reduce the size of a water pump including a main impeller and a sub-impeller and to improve the mountability to an engine. .

  According to the first aspect of the present invention, the rotational force is transmitted from one end side, the other end side is inserted into the pump chamber, and the pump chamber is accommodated in the other end side of the drive shaft. A main impeller provided so as to be able to be intermittently connected via the main impeller, and a sub-impeller provided so as to be integrally rotatable on the tip side of the drive shaft with respect to the main impeller and having a smaller diameter than the main impeller. It is characterized by.

  According to the present invention, the water pump can be reduced in size by providing the sub-impeller on the front end side in the axial direction from the main impeller of the drive shaft.

It is a longitudinal section showing a 1st embodiment of a water pump concerning the present invention. It is a disassembled perspective view of the water pump of this embodiment. The secondary impeller provided for this embodiment is shown, A is a perspective view and B is a front view. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the water pump which concerns on this invention. The secondary impeller provided to this embodiment is shown, A is a side view and B is a front view. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the water pump which concerns on this invention. The secondary impeller used for this embodiment is shown, A is a front view and B is a side view.

  Hereinafter, each embodiment of the water pump according to the present invention will be described in detail with reference to the drawings.

The water pump 1 is applied to a cooling device that circulates an antifreeze liquid (ethylene glycol) that is cooling water between a radiator of an automobile and an engine.
[First Embodiment]
As shown in FIGS. 1 to 3, the water pump 1 is directly attached to the side portion of the cylinder block 01 of the internal combustion engine by a plurality of mounting bolts 28, and cooperates with the front end recessed groove on the cylinder block 01 side. The pump housing 2 in which the pump chamber 3 is formed, the pulley 4 rotatably supported by a single ball bearing 5 on the rear end side of the pump housing 2, and the pump housing 2 are inserted into the pump housing 2. A drive shaft 6 having one end integrally connected to the pulley 4, a main impeller 7 fixed to the other end of the drive shaft 6 and rotatably accommodated in the pump chamber 3, It is mainly composed of a mechanical seal 8 interposed between the pump housing 2 and the drive shaft 6 and sealing between the pump chamber 3 and the ball bearing 5.

  In the cylinder block 01, an introduction passage 03 for introducing cooling water from a radiator side (not shown) is formed in an outer portion on the water pump 1 side. The introduction passage 03 communicates with the pump chamber 3 from the direction perpendicular to the axis and has a uniform passage inner diameter.

  The pump housing 2 is integrally formed of an aluminum alloy material, a housing body 9 is formed in a deformed annular shape on the pump chamber 3 side, and a step-shaped cylindrical portion is formed on the rear end side of the housing body 9. 10 are integrated.

  The housing body 9 is formed with a flat annular mounting surface 9a at the front end that abuts against a flat surface provided on the side of the cylinder block 01, and a mounting bolt 28 screwed and fixed to the cylinder block 01 on the outer periphery. A plurality of boss portions 9c constituting a bolt hole 9b through which is inserted.

  In addition, a discharge port 9d is formed in the housing body 9 for discharging the cooling water flowing into the pump chamber 3 from the introduction passage 03 into the water jacket (not shown) as the main impeller 7 rotates. . A part of the discharge port 9d is formed between a recess formed on the outer surface of the front end of the cylinder block 01.

As shown in FIG. 1, the cylindrical portion 10 includes a large-diameter portion 10a on the pump chamber 3 side, a medium-diameter portion 10b extending from the large-diameter portion 10a toward the ball bearing 5, and the medium-diameter portion. The small-diameter portion 10c extends from 10b toward the large-diameter shaft portion of the drive shaft 6.
The middle diameter portion 10b is formed with an annular space chamber 11 into which water droplets of cooling water leaked from the mechanical seal 8 are introduced below the gravity direction, and below the annular space chamber 11, A drain chamber (not shown) for collecting and storing water droplets dropped from the annular space chamber 11 is formed.

The pulley 4 is integrally formed in a disc shape made of synthetic resin, and is driven from a central fixing portion 4a in which the drive shaft 6 is coupled by insert molding at the center, and an axial front end edge of the central fixing portion 4a. A disc-shaped flange wall 4b extending in the radial direction of the shaft 6, a large-diameter cylindrical portion 4c bent in the axial direction of the drive shaft 6 from the outer peripheral edge of the flange wall 4b, and the cylindrical portion 4c It is comprised from the belt mounting part 4d protrudingly provided by the outer peripheral surface.
In the cylindrical portion 4c, an outer ring 5b of the ball bearing 5 is press-fitted and fixed to an inner peripheral surface via a metal cylindrical insert 12. In the belt mounting portion 4d, a transmission belt wound around a driving pulley fixed to a distal end portion of a crankshaft (not shown) is wound around an outer periphery formed in a wave shape so that a rotational force is transmitted. It has become.

The ball bearing 5 is a general one, and an inner ring 5a press-fitted into the outer peripheral surface of the small-diameter portion 10c of the cylindrical portion 10, the outer ring 5b press-fitted into the inner periphery of the insert 12, and the inner ring It is comprised from the some ball | bowl 5c provided so that rolling was possible via the holder | retainer between 5a and the outer ring | wheel 5b.
Further, as shown in FIG. 2, a thin annular shield plate 13 is sandwiched and fixed between the inner ring 5a and the annular protrusions of the medium diameter portion 10b on the outer periphery of the small diameter portion 10c. The shielding plate 13 is disposed so as to cover the rear end edge side of the ball bearing 5 so as to prevent dust from the outside from entering the ball bearing 5.
The drive shaft 6 is made of a metal material, and as shown in FIGS. 1 and 2, a large-diameter shaft portion 6a formed on one end of the pulley 4 side, and the large-diameter shaft portion 6a. A medium diameter shaft portion 6b integrally provided on the end portion side of the main impeller 7 and a small diameter shaft portion 6c integrally provided on the tip side of the medium diameter shaft portion 6b, and the small diameter shaft from the large diameter shaft portion 6a. The step 6c is formed in a small diameter shape up to the portion 6c.

  An annular groove 6d is formed on the outer periphery of the distal end of the large-diameter shaft portion 6a on the pulley 4 side. The annular groove 6d allows water droplets cut at the edge of the groove to pass from the annular space chamber 11 to the annular space chamber 11. It is made to drip into the storage chamber outside the figure provided in the lower part of the.

  A drive ring 14 is press-fitted and fixed from the axial direction on the outer peripheral surface of the portion connected to the small-diameter shaft portion 6c of the medium-diameter shaft portion 6b. The drive ring 14 is integrally formed of a metal material, and is formed integrally with a cylindrical main body 14a that is press-fitted and fixed to the outer peripheral surface of the medium-diameter shaft portion 6b from the axial direction, and a front end of the cylindrical main body 14a. It is comprised from the control flange part 14b. The cylindrical main body 14a has an inner diameter slightly smaller than the outer diameter of the medium diameter shaft portion 6b, and is press-fitted into the medium diameter shaft portion 6b.

  The restriction flange portion 14b is integrally formed with an annular convex portion (step portion) 14c having a small step diameter on one side surface of the cylindrical main body 14a.

  The small-diameter shaft portion 6c extends relatively long in the axial direction, and a bearing portion 15 (underwater bearing) is rotatably provided on the outer periphery of a substantially central portion in the axial direction. The bearing portion 15 is integrally formed of a carbon material and has an axial length that is set shorter than the axial length of the small-diameter shaft portion 6c.

  The drive ring may be formed integrally with the drive shaft 6.

  A cylindrical driven ring 16 is press-fitted and fixed to the outer periphery of the bearing portion 15. The driven ring 16 includes a cylindrical ring body 16a integrally formed of stainless steel, a flange portion 16b integrally provided at one end in the axial direction of the ring body 16a opposite to the drive ring 14, It is mainly composed of a plurality of projecting portions 16c provided integrally at equal circumferential positions on the inner side surface of the flange portion 16b.

  The follower ring 16 is configured such that the entire length in the axial direction including the flange portion 16 b is set substantially the same as the axial length of the bearing portion 15, and the inner diameter is slightly smaller than the outer diameter of the bearing portion 15. It is formed small and the press-fitting allowance is secured.

  The ring main body 16a is slidable from the axial direction on the opposed surface of the cylindrical main body 14a of the drive ring 14 facing the other end surface in the axial direction, or opposed with a slight gap, and has an outer diameter. Are set to be substantially the same as the outer diameter of the cylindrical main body 14a and are formed on the outer peripheral surfaces continuous with each other.

  Between each projection part 16c of the said flange part 16b, the locking groove 16d to which the one end part 20a of the clutch spring 20 mentioned later is locked is formed.

  The driven ring 16 may be formed integrally with the main impeller 7.

  The main impeller 7 is integrally formed of an aluminum alloy material. As shown in FIGS. 1 and 2, the main impeller 7 is formed in a substantially disk-like base portion 7a and radially on the front outer peripheral side of the base portion 7a from the center side. It is mainly composed of six blade portions 7b.

  The main impeller 7 is disposed on the outer peripheral side of the small-diameter shaft portion 6c of the drive shaft 6 via a bearing portion (underwater bearing) 15 and a driven ring 16, and a cylindrical holding hole 7c is formed in the center of the base portion 7a in the axial direction. It is formed to penetrate. The holding hole 7c is formed to have a relatively large diameter, and has an axial length in which about 2/3 of the driven ring 16 is accommodated.

  Further, the hole edge of the holding hole 7 c is fixed by caulking to a portion in the vicinity of the flange portion 16 b of the driven ring 16. Therefore, the main impeller 7 rotates integrally with the bearing portion 15 via the driven ring 16 and rotates relative to the drive shaft 6. Further, the holding hole 7c is configured to fit and hold a control member 21 described later on the inner periphery.

  A sub-impeller 32 is press-fitted and fixed to the tip of the small-diameter shaft portion 6 c of the drive shaft 6. This sub-impeller 32 is a so-called axial flow type, and is disposed at a position facing the pump chamber 3 in the introduction passage 03 as shown in FIGS. 1, 3A, and B, and is integrally formed of a synthetic resin material. In addition, a substantially cylindrical base portion 32a extending in the axial direction, six blade portions 32b projecting radially from the outer peripheral surface of the tip portion of the base portion 32a, and an outer edge of each blade portion 32b are integrated. It is mainly comprised from the annular part 32c provided in.

  The base portion 32a has a solid inner end, but is formed with a press-fit hole 32e into which the distal end portion of the small-diameter shaft portion 6c of the drive shaft 6 is press-fitted in the inner axial direction of the rear end portion 32d. .

  The press-fitting hole 32e is formed from the rear end surface of the rear end part 32d to a predetermined length in the direction of the internal axis, and has an inner diameter slightly smaller than the outer diameter of the small-diameter shaft part 6c to form a press-fitting allowance. Has been.

  Each of the blade portions 32b is disposed on the outer peripheral surface of the base portion 32a at a position of about 60 ° in the circumferential direction, and each blade portion 32b is formed in a flat plate shape, and in order to obtain a water flow from the front end side to the rear end side. Inclined in the same direction. Further, the outer diameter of the annular portion 32 c is formed smaller than the inner diameter of the introduction passage 03, and a predetermined gap S is formed between the outer peripheral edge and the inner peripheral surface of the introduction passage 03.

  As shown in FIGS. 1 and 2, a metal disk-shaped holding plate 17 is interposed between the rear end surface of the base portion 32 a and the front end surface of the bearing portion 15. The holding plate 17 is formed with a press-fitting hole 17a into which the small-diameter shaft portion 6c is press-fitted at the center, and an outer diameter is formed slightly larger than the outer diameter in the driven ring 16, and the bearing is formed on the outer peripheral side. The axial movement of the portion 15 and the driven ring 16 is restricted.

  Clutch mechanisms are provided on both outer peripheral sides of the cylindrical main body 14 a of the drive ring 14 and the ring main body 16 a of the driven ring 16.

  The clutch mechanism includes a clutch spring 20 disposed on both outer circumferential sides of the drive ring 14 and the driven ring 16, and a clutch spring 20 disposed on the outer circumferential side of the clutch spring 20. The clutch spring 20 is disposed on the drive ring 14 and the driven ring 16. The control member 21 that controls the connection and the rotation limiting mechanism 22 that controls the rotation of the control member 21 are configured.

  The clutch spring 20 is formed in a long coil shape in the axial direction, wound around the outer peripheral surfaces of the cylindrical main body 14a and the ring main body 16a from the axial direction, and has a spring force in a direction in which the diameter is always reduced. The drive ring 14 and the driven ring 16 are connected by acting.

  The clutch spring 20 has one end portion 20a bent in the axial direction and fixed to the locking groove 16d of the driven ring 16, and the other end portion 20b bent in the radial direction. Is engaged and fixed in an engagement groove 21 c formed on one end side in the axial direction of the control member 21.

  As shown in FIGS. 1 and 2, the control member 21 includes a main body 21a formed in a substantially cylindrical shape, and a pair of arm portions 21b and 21b formed in radially symmetric positions on the outer peripheral surface of the main body 21a. And the inner peripheral surface of the main body 21a is arranged so as to cover the outer peripheral surface of the clutch spring 20 with a slight gap.

  The main body 21a is set to have a predetermined length along the axial direction, has an outer diameter slightly smaller than the inner diameter of the holding hole 7c of the main impeller 7, and one end portion in the axial direction has the holding hole 7c. The other end is slidably fitted to the outer peripheral surface of the annular convex portion 14c.

  That is, the control member 21 is not fixed to any member, and one end portion of the main body 21a is slidably fitted to the inner peripheral surface of the holding hole 7c, and the other end portion Is slidably fitted and held on the outer peripheral surface of the annular convex portion 14c. The other end is in contact with the inner surface of the restriction flange portion 14b from the axial direction. Note that an engaging groove 21c formed in a substantially U-shape is cut out along the axial direction at the other end.

  The two arm portions 21b and 21b are fixed base portions fixed at substantially the center position in the axial direction of the outer peripheral surface of the main body 21a, and project from the fixed base portions in the radial direction and bent in the axial direction so that the mechanical seal 8 The both arm portions 21b, which are configured from the distal end portion extending to the outer peripheral position, have an outer peripheral surface formed in a circular arc shape along the circumferential direction of the main body 21a.

  The control member 21 is configured to rotate integrally with the driven ring 16 and the bearing portion 15 via one end portion 20 a of the clutch spring 20, and the rotation limiting mechanism provided in the pump housing 2. The rotation is appropriately limited (restricted) by 22, and the clutch spring 20 is expanded and deformed by this limiting action.

  As shown in FIGS. 1 and 2, the rotation limiting mechanism 22 is constituted by an electromagnetic solenoid, and is accommodated and fixed in a holding hole 2a formed in a side portion of the pump housing 2 on the large diameter portion 10a side. 23 and a solenoid portion 24 provided on the rear end side of the solenoid body 23.

  The solenoid body 23 is formed in a substantially cylindrical shape and is housed and held in a liquid-tight droplet in the holding hole 2a via a seal ring 34 that is fixed to the outer peripheral sealing groove. A sliding hole 23a that is continuous with the through hole 2b formed in the pump housing 2 is formed in a substantially central position.

  The solenoid unit 24 includes an electromagnetic coil, a fixed core, a movable plunger 25 and the like housed in a casing, and a push rod 26 fixed to the movable plunger 25 is provided at the tip. In addition, a connector portion 24 a that is electrically connected to an electronic controller described later is integrally provided at the outer end portion of the solenoid portion 24.

  The push rod 26 has a base end portion fixed to the movable plunger, and a tip end portion that is freely inserted into the sliding hole 23a and the through hole 2b and can be moved back and forth in the direction of the arm portion 21b of the control member 21. Is provided. That is, when the push rod 26 is energized to the electromagnetic coil, the push rod 26 moves forward via the movable plunger, and the tip end portion comes into contact with one side surface of the one arm portion 21b from the radial direction to control the push rod 26. While restricting and restricting free rotation of the member 21 in the same direction as the drive shaft 6, when the energization to the electromagnetic coil is interrupted, the member 21 is moved backward by the spring force of the coil spring 27 wound around the outer periphery of the tip portion. There is no contact with either one of the arm portions 21b. The electromagnetic coil of the solenoid unit 24 is configured such that a control current is supplied or cut off from an electronic controller (not shown).

  This electronic controller detects the current engine state based on information signals from a crank angle sensor, an air flow meter, an engine water temperature sensor, etc., and controls various devices such as a fuel injection valve. In particular, on the basis of an information signal from the engine water temperature sensor, a control current is supplied to or cut off from the electromagnetic coil of the solenoid unit 24 so that the clutch spring 20 is deformed or expanded through the control member 21. It has become.

  The main impeller 7 is a through-hole 2 that guides the cooling water supplied into the pump chamber 3 to the back of the main impeller 7 (in the direction of the mechanical seal 8) at a position facing the substantially axial direction of the clutch spring 20 of the main impeller 7. Two water guide holes 30 are formed.

That is, as shown in FIG. 1, the water guide hole 30 is formed at a substantially symmetrical position substantially in the radial center of the base portion 7a of the main impeller 7, and communicates with the annular clearance on the outer peripheral side of the clutch spring 20 from the axial direction. In addition, the control member 21 communicates with the control member 21 from the axial direction.
[Effects of First Embodiment]
Hereinafter, the operation of the water pump 1 according to the first embodiment will be described.

  First, when the engine is cold-started at a predetermined temperature or lower, the electronic controller energizes and energizes the electromagnetic coil of the solenoid unit 24 by an information signal from the engine water temperature sensor. Then, the push rod 26 advances against the spring force of the coil spring 27 through the movable plunger, and the push rod tip portion comes into contact with the side surface of the tip portion of one arm portion 21b of the control member 21 from the radial direction. Thus, the rotation of the control member 21 is limited.

  As a result, the clutch spring 20 is deformed in the diameter increasing direction via the other end 20 b of the clutch spring 20, so that the inner peripheral surface of the clutch spring 20 is separated from the outer peripheral surfaces of the drive ring 14 and the driven ring 16. The connection of both 14 and 16 is cut apart. Accordingly, the drive ring 14 continues to rotate integrally with the drive shaft 6 as it is, but since the driven ring 16 stops rotating, the main impeller 7 also stops rotating.

  At this time, since the sub impeller 32 is always rotating together with the drive shaft 6, the cooling water in the introduction passage 03 is drawn and sent to the discharge port 9d through the pump chamber 3. There are few.

  In this way, the pump action by the main impeller 7 is stopped and only the sub impeller 32 is rotating. Therefore, the cooling water is slightly supplied from the introduction passage 03 into the pump chamber 3 and is discharged from the discharge port 9d to the engine. A small amount of cooling water is supplied into the water jacket. Therefore, the warm-up performance at the time of cold start is not greatly affected.

  Thereafter, when the engine temperature rises above a predetermined level, the water temperature sensor that detects the engine temperature cuts off the energization from the electronic controller to the electromagnetic coil of the solenoid unit 24. For this reason, since the push rod 26 is retracted by the spring force of the coil spring 27, the contact with the arm portion 21b is released, and the control member 21 is allowed to freely rotate.

  Therefore, the clutch spring 20 is restored to its original shape by its own reduced diameter deforming force, and the drive ring 14 and the driven ring 16 are tightened to integrally connect the both 14 and 16. Therefore, the main impeller 7 rotates integrally with the rotational force of the drive shaft 6 to perform a pump action, and as shown by the arrow in FIG. Since the water is supplied from the discharge port 9d into the water jacket, the engine can be efficiently cooled.

  At this time, since the auxiliary impeller 32 is also rotating, the assist pump action (supercharging action) improves the pump efficiency of the main impeller 7 and increases the engine cooling effect.

  On the other hand, the high-pressure cooling water in the pump chamber 3 passes through the water guide holes 30 and a part of the annular coolant on the outer surface of the control member 21 and the outer periphery of the clutch spring 20 as shown by the arrows in FIG. It flows into the gap or the like, flows in the direction of the mechanical seal 8 as it is, and returns from here to the pump chamber 3.

  Thereby, after the warm-up is completed, the cooling water of the pump chamber 3 is forcibly supplied to the clutch spring 20 and its surroundings through the water guide holes 30. Since the friction powder is washed away and the adhesion of the friction powder is eliminated, it is possible to suppress a decrease in the performance of the clutch mechanism.

  Further, the sleeve portion of the mechanical seal 8 is positively cooled by the cooling water flowing in the direction of the mechanical seal 8, and seizure due to sliding friction with the drive shaft 6 can be effectively suppressed.

  As described above, even when the main impeller 7 does not rotate during the low-temperature start and the pumping action is not performed, even if a slight amount of cooling water accompanies the rotation of the sub-impeller 32, the clutches are connected from the respective water guide holes 30. Since the cooling water is forcibly supplied to the spring 20 and the vicinity thereof, the friction powder and the like due to the operation of the clutch spring 20 is washed away, and the adhesion of the friction powder is eliminated.

  Further, at the time of the low temperature start, the main impeller 7 does not rotate, but the sub impeller 32 rotates and the flow of cooling water is ensured slightly, so that the malfunction of the water temperature sensor provided in the engine is suppressed. can do. That is, for example, if the cooling does not flow at all in the water jacket and stagnates, the water temperature sensor may malfunction and the engine may overheat. However, if it is flowing slightly in the water jacket, the malfunction of the water temperature sensor is avoided and normal operation is maintained, so that the occurrence of engine overheating can be suppressed.

  In the present embodiment, as described above, the secondary impeller 32 is provided at the tip of the small diameter shaft portion 6c of the drive shaft 6 that is spaced forward from the main impeller 7, so There is no need to increase the outer diameter of the impeller 7. Therefore, even if the auxiliary impeller 32 is provided, the enlargement of the outer diameter of the water pump 1 is suppressed, and it becomes possible to reduce the size.

  Further, since the cooling water always flows in the direction of the main impeller 7 along with the rotation of the sub impeller 32 and a predetermined pressure is maintained in the pump chamber 3, even if the rotation of the main impeller 7 starts, the low pressure portion Since the generation of a large differential pressure between the high pressure portion and the high pressure portion can be suppressed, the generation of cavitation can be suppressed. From this point, the pump efficiency can be improved.

  Further, since the clutch mechanism including the clutch spring 20, the control member 21, and the rotation limiting mechanism 22 is provided inside the pump housing, the water pump 1 can be downsized in this respect as well.

  Further, as described above, one end portion of the control member 21 is slidably fitted and held by the inner peripheral surface of the holding hole 7c, and the other end portion is set by the outer peripheral surface of the annular convex portion 14c. It is slidably fitted and held. Accordingly, the control member 21 is positioned in the radial direction by being slidably held on the inner peripheral surface of the holding hole 7c and the outer peripheral surface of the annular convex portion 14c. Further, since the other end is in contact with the inner surface of the restriction flange portion 14b, the axial positioning is performed.

As described above, the radial positioning and the axial positioning of the control member 21 are performed, so that the shake is suppressed and the stable operation of the control member 21 is obtained. Further, both ends of the control member 21 are slidably held, and the rotational load on the control member 21 is reduced by suppressing the shake by positioning in the radial direction and the axial direction.
[Second Embodiment]
FIG. 4 shows the second embodiment, and the basic configuration is the same as that of the first embodiment, except that the sub-impeller 31 is a mixed flow type.

  That is, as shown in FIGS. 4, 5 </ b> A, and B, the sub impeller 31 is disposed at a position facing the pump chamber 3 in the introduction passage 03, and is integrally formed of a synthetic resin material and has a tapered tip. It is mainly composed of a substantially conical base portion 31a extending in the axial direction and six blade portions 31b integrally provided on the tapered outer peripheral surface of the base portion 31a.

  The base portion 31a has a tip surface 31d formed in a spherical shape to reduce the flow resistance of the cooling water, and has a cylindrical projection 31c integrally formed at the rear end portion of the enlarged diameter. A press-fitting hole 31e is formed in the axial direction in which the tip of the small-diameter shaft portion 6c of the drive shaft 6 is press-fitted.

  The press-fitting hole 31e is formed to a predetermined length from the rear end surface of the protrusion 31c in the direction of the internal axis, and the inner diameter is slightly smaller than the outer diameter of the small-diameter shaft part 6c to form a press-fitting allowance. ing.

  Each of the blade portions 31b is disposed on the outer peripheral surface of the base portion 31a at a position of about 60 ° in the circumferential direction, and is formed in an inclined diameter increasing shape from the front end portion to the rear end portion of the base portion 31a. It has a torsional shape so that it can be hung on the rear end side to obtain a water flow. Further, the outer diameter of each blade 31b is formed smaller than the inner diameter of the introduction passage 03, and a predetermined gap S is formed between the outer peripheral edge and the inner peripheral surface of the introduction passage 03.

  Therefore, according to this embodiment, the pumping action accompanying the constant rotation of the sub impeller 31 can provide the same effects as the first embodiment. In particular, in this embodiment, the sub impeller 31 is a mixed flow type. As a result, the drawability of the cooling water into the pump chamber 3 is enhanced, so that the supercharging action of the main impeller 7 is improved and the generation of cavitation can be further suppressed.

Further, since the other configuration is the same as that of the first embodiment, the water pump 1 can be downsized, the warm-up performance can be improved at the time of cold start by the clutch spring 20, and the engine can be cooled quickly after the warm-up is completed. These are the same as in the first embodiment.
[Third Embodiment]
FIG. 6 shows a third embodiment in which the secondary impeller 19 is a centrifugal type. That is, the sub-impeller 19 is integrally formed of a synthetic resin material, and is disposed at a position facing the pump chamber 3 of the introduction passage 03 as shown in FIG. 6, and as shown in FIGS. It is mainly composed of a substantially streamlined base portion 19a and six blade portions 19b protruding radially from the outer peripheral surface of the base portion 19a.

  The base portion 19a has a front end surface 19e formed in a spherical shape in order to reduce the flow resistance of the cooling water, and has a cylindrical protrusion 19c integrally formed at the rear end portion in the inner axial direction. A press-fitting hole 19d into which the tip of the small-diameter shaft portion 6c of the drive shaft 6 is press-fitted is formed. The press-fitting hole 19d is formed from the rear end surface of the protrusion 19c to a predetermined length in the direction of the internal axis, and has an inner diameter slightly smaller than the outer diameter of the small-diameter shaft part 6c to form a press-fitting allowance. ing.

  Each of the blade portions 19b is disposed on the outer peripheral surface of the base portion 19a at a position of about 60 ° in the circumferential direction, and is bent in a curved shape so that the substantially central portion in the radial direction becomes the maximum concave portion, and the outer diameter is A predetermined gap S is formed between the outer peripheral edge and the inner peripheral surface of the introduction passage 03, which is smaller than the inner diameter of the introduction passage 03.

  Therefore, according to this embodiment, the same effect as the first embodiment can be obtained by the pump action accompanying the constant rotation of the sub-impeller 32.

  The present invention is not limited to the configuration of each of the embodiments described above, and the configuration can be changed without departing from the spirit of the invention.

The technical ideas of the invention other than the claims ascertained from the embodiment will be described below.
[Claim a] In the water pump according to claim 1,
Formed in a cylinder block of an internal combustion engine, having an introduction passage for introducing cooling water into the pump chamber;
The sub-impeller has a plurality of blade portions, and a part of the blade portions is disposed in the introduction passage.

According to this invention, since a part of the blade portion of the sub-impeller is arranged in the introduction passage, the space can be used effectively, so that the water pump can be reduced in size.
[Claim b] The water pump according to claim a,
The sub-impeller is a water pump characterized in that the blade portion is disposed across the introduction passage and the pump chamber.

According to the present invention, even if the auxiliary impeller is provided on the tip end side of the drive shaft, it is not necessary to increase the axial length of the entire water pump, and the flow of the cooling water generated by the auxiliary impeller is transmitted to the main impeller. Therefore, the pump efficiency can be improved by the supercharging effect.
[Claim c] The water pump according to claim b,
The sub impeller is a water pump characterized in that all of the blade portions are accommodated in an introduction passage.
[Claim d] The water pump according to claim 1,
The sub-impeller is an axial flow type that forms an axial flow with rotation, and is a water pump.

By making the auxiliary impeller an axial flow type, the cooling water sucked by the auxiliary impeller can be flowed to the main impeller, so that the pump efficiency can be improved and the occurrence of cavitation can be suppressed.
(Claim e) The water pump according to claim a,
The sub-impeller is a centrifugal pump.

According to the present invention, the axial flow is not generated, but the flow can be generated, so that the pump driving of the main impeller can be assisted.
[Claim f] The water pump according to claim 1,
The sub-impeller is a mixed flow type that forms a mixed flow with rotation.

According to this invention, since the flow of the cooling water discharged from the blades is on the conical surface with the center of the drive shaft as the axis, the supercharging effect of the rotation of the main impeller can be exhibited as it is, so that the pump The efficiency can be greatly improved and the occurrence of cavitation can be suppressed.
[Claim g] The water pump according to claim d,
The water pump is characterized in that the sub-impeller is accommodated in an introduction passage.
(Claim h) In the water pump according to claim 3,
The water pump is characterized in that the control member is slidably held by a holding portion provided on the drive ring or the impeller.
[Claim i] In the water pump according to claim 1,
The sub-impeller is integrally formed of a resin, and is constituted by a conical base portion at the center portion and a plurality of blade portions provided on the outer peripheral side of the base portion. .

According to this invention, the shape of the sub impeller can be freely set by resin molding.
(Claim j) In the water pump according to claim 3,
The water pump is characterized in that the control member is made of an iron-based metal.

According to the present invention, the control member is not deteriorated by heat. If the impeller is also an iron-based metal, the clearance of fitting does not change because the linear expansion coefficient is close.
(Claim k) In the water pump according to claim h,
The water pump is characterized in that the holding portion is constituted by a bearing installed on the drive ring or the main impeller.

According to the present invention, since sliding is performed by the bearing, smooth slidability can be obtained. In addition, the resin impeller has an effect of suppressing variation in the fitting gap due to thermal expansion of the resin.
[Claim 1] In the water pump according to claim 3,
The water pump is characterized in that the control member has a cylindrical main body fitted and held on an outer peripheral surface of a cylindrical holding portion provided on the inner peripheral side of the main impeller.

According to this invention, since the area which suppresses inclination can be taken wide by pressing from the outer peripheral side, stable holding can be obtained.
[Claim m] In the water pump according to claim 3,
The water pump is characterized in that the control member is fitted and held on the outer peripheral side of a cylindrical holding portion in which a cylindrical main body extends along the axial direction on the back side of the impeller.
[Claim n] In the water pump according to claim 3,
The control member is a water pump characterized in that a cylindrical main body is fitted and held in a cylindrical holding portion provided on the outer periphery of the drive ring.

According to the present invention, by holding the control member using the drive ring, there is only the drive ring between the drive shaft and the control member, and since there are few intervening parts, an increase in the number of parts is suppressed. At the same time, more accurate shake prevention can be achieved.
(Claim o) In the water pump according to claim 3,
A driven ring is provided between the bearing and the main impeller;
The driven ring includes an extending portion extending in a radial direction at one end portion and an axial direction extending from an outer peripheral edge of the extending portion, and an outer peripheral surface of the one end portion of the control member is slidably fitted. A water pump characterized by having a cylindrical vibration suppressing portion held together.

According to the present invention, since the vibration suppressing portion can be provided on the driven ring, the degree of freedom in design increases.
[Claim q] In the water pump according to claim h,
The water pump is characterized in that the holding portion is provided only in the drive ring.
[Claim r] In the water pump according to claim 1,
The water pump according to claim 1, wherein the holding portion is provided only in the impeller.
[Claim s] In the water pump according to claim 1,
The water pump according to claim 1, wherein the holding portion is provided on both the drive ring and the impeller.

According to the present invention, the shake suppressing effect is further improved by holding both ends of the control member.
[Claim t] In the water pump according to claim 1,
The water pump according to claim 1, wherein the holding portion includes a restricting portion that restricts axial movement of the control member.

  According to this invention, by restricting the axial movement, it is possible to prevent the control member from moving in the axial direction due to the water flow or the water pressure and the clutch spring to be in an unreasonable posture, thereby preventing uneven wear.

Claims (22)

A driving shaft in which rotational force is transmitted from one end side and the other end side is inserted into the pump chamber;
A main impeller that is housed in the pump chamber and provided on the other end side of the drive shaft via a clutch mechanism;
A sub-impeller that is provided so as to be integrally rotatable on a tip side of the main impeller of the drive shaft, and is formed with a smaller diameter than the main impeller;
A water pump comprising: The water pump according to claim 1,
The clutch mechanism includes a drive ring that rotates integrally with the drive shaft;
A driven ring provided on the main impeller and rotating integrally with the main impeller;
A clutch spring that is arranged across the outer peripheral surfaces of the drive ring and the driven ring, and is reduced in diameter by its own elastic force;
A control member that is rotatably arranged with a predetermined gap on an outer peripheral side of the clutch spring, and that deforms the clutch spring in a diameter expansion direction according to a water temperature state;
A rotation limiting mechanism for limiting rotation of the control member;
A water pump comprising: The water pump according to claim 2,
The water pump is characterized in that the control member is slidably held by a holding portion provided on the drive ring or the impeller. The water pump according to claim 3,
The water pump is characterized in that the holding portion is constituted by a bearing installed on the drive ring or the main impeller. The water pump according to claim 3,
The water pump is characterized in that the holding portion is provided only in the drive ring. The water pump according to claim 3,
The water pump according to claim 1, wherein the holding portion is provided only in the impeller. The water pump according to claim 3,
The water pump according to claim 1, wherein the holding portion is provided on both the drive ring and the impeller. The water pump according to claim 3,
The water pump according to claim 1, wherein the holding portion includes a restricting portion that restricts axial movement of the control member. The water pump according to claim 2,
The water pump is characterized in that the control member is made of an iron-based metal. The water pump according to claim 2,
The water pump is characterized in that the control member has a cylindrical main body fitted and held on an outer peripheral surface of a cylindrical holding portion provided on the inner peripheral side of the main impeller. The water pump according to claim 2,
The water pump is characterized in that the control member is fitted and held on the outer peripheral side of a cylindrical holding portion in which a cylindrical main body extends along the axial direction on the back side of the impeller. The water pump according to claim 2,
The control member is a water pump characterized in that a cylindrical main body is fitted and held in a cylindrical holding portion provided on the outer periphery of the drive ring. The water pump according to claim 2,
A driven ring is provided between the bearing and the main impeller;
The driven ring includes an extending portion extending in a radial direction at one end portion and an axial direction extending from an outer peripheral edge of the extending portion, and an outer peripheral surface of the one end portion of the control member is slidably fitted. A water pump characterized by having a cylindrical vibration suppressing portion held together. The water pump according to claim 1,
The sub-impeller is a mixed flow type that forms a mixed flow with rotation. The water pump according to claim 1,
The sub-impeller is a centrifugal pump. The water pump according to claim 1,
The sub-impeller is an axial flow type that forms an axial flow with rotation, and is a water pump. The water pump according to claim 1,
Formed in a cylinder block of an internal combustion engine, having an introduction passage for introducing cooling water into the pump chamber;
The sub-impeller has a plurality of blade portions, and a part of the blade portions is disposed in the introduction passage. The water pump according to claim 17,
The sub-impeller is a water pump characterized in that the blade portion is disposed across the introduction passage and the pump chamber. The water pump according to claim 18, wherein
The sub impeller is a water pump characterized in that all of the blade portions are accommodated in an introduction passage. The water pump according to claim 1,
The water pump is characterized in that the sub-impeller is accommodated in an introduction passage. The water pump according to claim 1,
The sub-impeller is integrally formed of a resin, and is constituted by a conical base portion at the center portion and a plurality of blade portions provided on the outer peripheral side of the base portion. . A pump housing having a pump chamber therein;
A rotational force is transmitted from one end side, and a drive shaft rotatably supported in the pump housing;
A main impeller provided in the pump chamber and provided on the other end of the drive shaft;
A clutch mechanism for intermittently connecting the drive shaft and the main impeller;
With
A water pump characterized in that a sub-impeller smaller in diameter than the main impeller is provided on the tip side of the main impeller of the drive shaft so as to be able to rotate integrally with the drive shaft.

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