JP3718122B2 - Centrifugal centrifugal pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a centrifugal swirl pump, and more particularly to a centrifugal swirl pump suitable for use in a washer pump for discharging window washer liquid or headlight washer liquid in a vehicle or the like.
[0002]
[Prior art]
Centrifugal centrifugal pumps are used in various fields. For example, they are widely used as washer pumps for discharging window washer fluid and headlight washer fluid in vehicles and the like.
[0003]
In this type of centrifugal centrifugal pump, an impeller is rotatably accommodated in a casing (volute casing). The casing is formed in a spiral shape as a whole, and starts to wind from a cut-off portion provided close to the tip portion of the impeller (in other words, the end portion of the casing is set as a volute winding start position). Are formed in a spiral shape in succession to the discharge port. As a result, a spiral spiral chamber is successively provided along the periphery of the impeller (see, for example, JP-A-8-261195).
[0004]
In this centrifugal swirl pump, energy (centrifugal force) can be given to the liquid by rotating the impeller in the casing. For example, the liquid flowing in from the inlet provided in the central portion of the impeller is placed on the outer periphery of the impeller. The liquid can be sequentially discharged to the discharge port through the spiral chamber provided along the discharge chamber, and the liquid can be discharged from the discharge port.
[0005]
By the way, there is a gap between the upper and lower peripheral edges of the impeller and the casing, and further, there is naturally a gap between the impeller blades and the blades, so that the flow rate sent from the impeller to the spiral chamber and the discharge port are discharged. It is considered that a part of the liquid flowing through the spiral chamber returns to the center of the impeller through the gap due to the difference in flow rate. When a part of the liquid sent from the impeller to the spiral chamber returns to the center of the impeller, the returning flow does extra work for sending the liquid to the discharge port. Will result in energy loss. In particular, the energy loss is significant in a low-flow and high-lift pump having a comparative rotation speed (specific speed) Ns≈80, such as a vehicle washer pump.
[0006]
Therefore, the flow returning to the center of the impeller despite being sent to the spiral chamber is a major negative factor that lowers the pump efficiency, and measures to prevent this have been eagerly desired.
[0007]
Therefore, the present applicant has already proposed a centrifugal centrifugal pump with low energy loss and improved pump efficiency (Japanese Patent Laid-Open No. 11-247798).
[0008]
According to the centrifugal vortex pump proposed in the above publication, an arc pump chamber and a vortex pump chamber are provided (a configuration in which the vortex portion starts in the middle of the casing), and the arc pump chamber (impeller blades) The flow amount of the liquid sent to the centrifugal pump chamber from the middle) can be reduced in the amount of flow returning to the center of the impeller, and the liquid to which energy (the action of centrifugal force) is applied from the impeller in the arc pump chamber It does not flow into the centrifugal pump chamber at once, and the flow velocity does not become excessively high, the difference from the liquid flow velocity in the vicinity of the discharge port becomes small, energy loss is greatly reduced, and it becomes extremely efficient.
[0009]
However, in recent years, when such a centrifugal swirl pump is mounted on a vehicle, further downsizing and higher efficiency have been demanded in accordance with an overcrowding in an engine room and a request for improving fuel consumption of the vehicle.
[0010]
[Problems to be solved by the invention]
In consideration of the above facts, the present invention can greatly reduce the energy loss and further increase the pump efficiency, and can be easily manufactured without increasing the number of parts with a simple structure and realized at low cost. The object is to obtain a centrifugal swirl pump that can be used.
[0011]
[Means for Solving the Problems]
The centrifugal centrifugal pump of the invention according to claim 1 is an centrifugal pump chamber configured by an arc casing formed concentrically with the impeller in a centrifugal spiral pump that discharges liquid from an outlet by rotation of an impeller; The arc pump chamber is continuously provided spirally from the arc pump chamber to the discharge port on the downstream side in the impeller rotation direction, and the circumferential end portion on the downstream side in the impeller rotation direction of the arc pump chamber is wound by volute. A spiral pump chamber configured by a volute casing set as a start position and having a circumferential end on the upstream side in the impeller rotation direction of the arc pump chamber set as a volute winding end position, and the spiral pump chamber When the winding angle from the volute winding start position to the volute winding end position is 115 degrees or more, 185 The volute winding start position of the volute casing is set so as to be less than that, the radius of the volute casing of the spiral pump chamber at the volute winding end position is R, and the radius of the arc casing of the arc pump chamber is r Is set such that the relationship of 0.15 <{(R−r) / r} <0.3 is established.
[0012]
The centrifugal centrifugal pump according to the first aspect includes an arc pump chamber constituted by an arc casing and a spiral pump chamber constituted by a volute casing. That is, the centrifugal centrifugal pump has a configuration in which the volute winding start position of the volute casing is set to be shifted by a predetermined range toward the discharge port as compared with the conventional centrifugal pump.
[0013]
When the impeller rotates, the liquid is boosted by being given energy from the impeller in the arc pump chamber, and further flows into the spiral pump chamber as the impeller rotates and is accelerated to be discharged from the discharge port.
[0014]
Here, the arc pump chamber of this centrifugal vortex pump is a region where the energy (the action of centrifugal force) given by the liquid from the impeller is small, and therefore the arc pump chamber (impeller of the impeller) depends on the set range of the arc pump chamber. The flow rate that flows out from the blades to the spiral pump chamber is adjusted, and the amount of liquid that is sent from the circular pump chamber (between the impeller blades) to the spiral pump chamber returns to the center of the impeller can be reduced. . Thereby, pump efficiency improves.
[0015]
On the other hand, when the volute winding start position of the volute casing is excessively close to the discharge port side (when the winding angle from the volute winding start position to the volute winding end position of the spiral pump chamber is excessively small), the arc pump In the chamber, the liquid to which energy (the action of centrifugal force) is applied from the impeller flows into the centrifugal pump chamber all at once, so that the flow velocity of the liquid flowing into this centrifugal pump chamber becomes too fast, and the flow velocity of the liquid near the discharge port As a result, the vortex is generated and the pump efficiency is lowered. Therefore, it is necessary to set the winding angle of the spiral pump chamber so that the difference between the flow velocity of the liquid near the discharge port and the flow velocity in the spiral pump chamber becomes small.
[0016]
That is, in this centrifugal centrifugal pump, the range of the arc pump chamber and the centrifugal pump chamber (in other words, the winding angle of the spiral pump chamber, that is, the volute winding start position) is suitably set (the winding angle is 115 degrees or more). By setting the angle to less than 185 degrees), the pressure can be increased by applying the maximum energy from the impeller to the liquid in the arc pump chamber in a range where the difference between the flow velocity of the liquid near the discharge port and the flow velocity in the spiral pump chamber is small. The liquid can be pumped out with maximum pump efficiency.
[0017]
Furthermore, in the centrifugal centrifugal pump according to claim 1, in addition to the knowledge that the difference between the flow velocity of the liquid in the vicinity of the discharge port and the flow velocity in the spiral pump chamber is made close as described above, the outflow from the arc pump chamber to the spiral pump chamber. If the amount differs greatly between the impellers, the rotation of the impeller is not constant and energy loss occurs, and if the outflow amount from the arc pump chamber to the spiral pump chamber is small between the impellers, the energy loss decreases, On the other hand, the outlet width of the spiral pump chamber (the opening width of the discharge port) was set to a certain region based on the knowledge that a flow between the spiral pump chamber and the arc pump chamber was generated and this caused a new energy loss. .
[0018]
That is, the value of the outlet width of the spiral pump chamber (the opening width of the discharge port) with respect to the radius of the arc pump chamber has an extremely effective region for the energy loss (if the energy loss is in a certain region) Extremely effective). That is, when the radius of the volute casing of the spiral pump chamber at the end of volute winding is R and the radius of the arc casing of the arc pump chamber is r, 0.15 <{(R−r) / r} <0.3. The relationship was established so that
[0019]
As a result, the difference in the outflow amount from the arc pump chamber to the spiral pump chamber between the impellers is small, and an unnecessary flow does not occur between the spiral pump chamber and the arc pump chamber (in a range where no energy loss occurs). , Pump efficiency can be maximized.
[0020]
Furthermore, since it has a simple structure consisting of an arc pump chamber (arc casing) and a spiral pump chamber (volute casing) and itself has a simple shape, it is easy to manufacture and low in cost, and the number of parts increases. I don't have to.
[0021]
As described above, in the centrifugal centrifugal pump according to the first aspect, the liquid energized by the impeller hardly generates a flow returning from the spiral pump chamber toward the center of the impeller, and the energy (centrifugal force) from the impeller in the arc pump chamber is hardly generated. The flow of liquid that has been applied) does not flow into the centrifugal pump chamber all at once, and the flow velocity does not become excessively high, and the difference from the flow velocity of the liquid near the discharge port is reduced, greatly reducing energy loss and pump efficiency. In addition, this can be realized easily with a simple structure without increasing the number of parts and at a low cost.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a longitudinal sectional view showing the overall configuration of a centrifugal centrifugal pump 10 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the main part of the centrifugal centrifugal pump 10.
[0023]
Centrifugal centrifugal pump 10 is applied to a washer pump device for discharging, for example, window washer fluid such as a vehicle.
[0024]
The centrifugal vortex pump 10 is configured such that a motor unit 10A and a pump unit 10B are integrally provided. The housing 12 constituting the motor unit 10A and the pump unit 10B is made of a resin and is formed in a substantially cylindrical shape. A resin end housing 14 is fixed to one end opening of the housing 12 so that the inside is sealed. ing. The end housing 14 is formed so as to protrude integrally at a substantially corner portion so that the connector portion 16 is exposed to the outside. An external connector (not shown) is fitted to the connector portion 16 and connected to an electric circuit portion (not shown) of the vehicle.
[0025]
Further, an intermediate portion of the housing 12 opposite to the end housing 14 (that is, a boundary portion between the motor portion 10 </ b> A and the pump portion 10 </ b> B) is partitioned by a partition wall 18. The armature shaft 20 of the motor unit 10 </ b> A is supported by the partition wall 18, and an armature (not shown) is accommodated in the housing 12.
[0026]
On the other hand, the pump unit 10B of the centrifugal vortex pump 10 is constituted by a housing 12 as a circular arc casing and a volute casing, and a bottom wall 22, and further, the tip of the armature shaft 20 reaches. An impeller 24 having a plurality of blades formed in the radial direction is attached to the tip of the armature shaft 20 and rotates together with the armature shaft 20 in the pump portion 10B. In addition, an inlet 26 and an outlet 28 formed in the housing 12 communicate with the pump unit 10B. That is, the pump unit 10 </ b> B constitutes a centrifugal spiral pump (centrifugal pump), and the liquid sucked from the inlet 26 can be pumped from the outlet 28 by the rotation of the impeller 24.
[0027]
Here, as shown in detail in FIG. 2, the pump portion 10 </ b> B in which the impeller 24 is accommodated is configured by an arc pump chamber 30 and a spiral pump chamber 32. The arc pump chamber 30 is configured by an arc casing portion 34 (a part of the housing 12) formed concentrically with the impeller 24. On the other hand, the spiral pump chamber 32 is located downstream of the arc pump chamber 30 in the impeller rotation direction (arrow R direction in FIG. 2) and is continuously provided from the arc pump chamber 30 to the outlet 28, and has a spiral volute. It is comprised by the casing part 36 (a part of housing 12). In the volute casing portion 36 (vortex pump chamber 32), the circumferential end on the downstream side in the impeller rotation direction of the arc pump chamber 30 is set as the volute winding start position A, and the impeller rotation direction upstream in the arc pump chamber 30 Is set as the volute winding end position B.
[0028]
Here, the winding angle θ from the volute winding start position A to the volute winding end position B in the spiral pump chamber 32 is preferably 115 degrees or more and less than 185 degrees, and the winding angle θ is in the above range. A volute winding start position A of the volute casing 36 is set. FIG. 2 shows an example in which the volute winding start position A of the volute casing portion 36 is set so that the winding angle θ of the spiral pump chamber 32 is 180 degrees.
[0029]
Furthermore, as shown in FIG. 2, the spiral pump chamber 32 has a radius of the volute casing part 36 at the volute winding end position B as R, and a radius of the arc casing part 34 of the arc pump chamber 30 as r.
0.15 <{(R−r) / r} <0.3
Is set to hold the relationship.
[0030]
The centrifugal centrifugal pump 10 having the above configuration is attached via a grommet 40 to a washer tank 38 disposed in the immediate vicinity of a tire wheel house of a vehicle.
[0031]
Next, the operation of this embodiment will be described.
[0032]
In the centrifugal centrifugal pump 10 having the above-described configuration, the arc pump chamber 30 constituted by the arc casing portion 34 and the centrifugal pump chamber 32 constituted by the volute casing portion 36 constitute the pump portion 10B. That is, the centrifugal vortex pump 10 has a configuration in which the volute winding start position A of the volute casing portion 36 (vortex pump chamber 32) is set to be deviated by a predetermined range toward the outlet 28 as compared with the conventional vortex pump. It has become.
[0033]
When the impeller 24 rotates in the pump unit 10B, the liquid is given pressure from the impeller 24 in the arc pump chamber 30 to be pressurized, and further flows into the spiral pump chamber 32 along with the rotation of the impeller 24 to be accelerated. It is discharged from the outlet 28.
[0034]
Here, the arc pump chamber 30 of the pump unit 10 </ b> B is a region where the energy (the action of centrifugal force) given by the liquid from the impeller 24 is small, and therefore the arc pump chamber 30 according to the set range of the arc pump chamber 30. The flow rate flowing from the impeller 24 to the spiral pump chamber 32 is adjusted, and a part of the liquid sent from the arc pump chamber 30 (between the impeller 24 blades) to the spiral pump chamber 32 is directed toward the center of the impeller 24. The amount of flow returning can be reduced. Thereby, the pump efficiency of the centrifugal centrifugal pump 10 is improved.
[0035]
On the other hand, when the volute winding start position A of the volute casing part 36 (spiral pump chamber 32) is excessively close to the outlet 28 side (when the winding angle θ of the spiral pump chamber 32 is excessively small), the arc pump In the chamber 30, the liquid to which energy (the action of centrifugal force) is applied from the impeller 24 flows into the centrifugal pump chamber 32 at a stretch, so that the flow velocity of the liquid flowing into the centrifugal pump chamber 32 becomes too fast, and the liquid near the outlet 28. The difference from the flow rate of the liquid becomes large, and vortices are generated, resulting in a decrease in pump efficiency. Therefore, it is necessary to set the winding angle θ of the spiral pump chamber 32 so that the difference between the flow rate of the liquid near the outlet 28 and the flow rate in the spiral pump chamber 32 becomes small.
[0036]
In this case, in the present embodiment, an example is shown in which the volute winding start position A of the volute casing portion 36 is set so that the winding angle θ of the spiral pump chamber 32 is 180 degrees. If the winding angle θ is in the range of 115 degrees or more and less than 185 degrees, the above-described effects can be obtained.
[0037]
Here, in FIG. 3, the correspondence relationship between the winding angle θ of the spiral pump chamber 32 and the pump efficiency is shown in a graph. In FIG. 3, line X is an example of a centrifugal pump having a capacity of 300 cc / 10 s, and line Y is an example of a centrifugal pump having a capacity of 400 cc / 10 s.
[0038]
As apparent from FIG. 3, it is understood that the winding angle θ should be in the range of 115 degrees or more and less than 185 degrees. Furthermore, when the winding angle θ of the spiral pump chamber 32 is set to 180 degrees as in the present embodiment, it can be seen that the pump efficiency is the highest.
[0039]
That is, if the winding angle θ of the spiral pump chamber 32 (in other words, the volute winding start position A of the volute casing portion 36) is set in the above range, the liquid flow rate in the vicinity of the outlet 28 and the spiral pump chamber 32 as described above. It can be seen that the difference in flow rate is reduced, the liquid can be boosted by applying energy to the liquid from the impeller 24 to the maximum, and the liquid can be delivered with the maximum pump efficiency.
[0040]
Thus, in the centrifugal centrifugal pump 10 according to the present embodiment, the range of the arc pump chamber 30 and the spiral pump chamber 32 (in other words, the winding angle θ of the spiral pump chamber 32, that is, the volute winding start position A) is suitable. In the range where the difference between the flow velocity of the liquid in the vicinity of the outlet 28 and the flow velocity in the spiral pump chamber 32 is small, the arc pump chamber 30 can increase the pressure by applying energy to the liquid from the impeller 24 to the maximum, Liquid can be pumped out with maximum pump efficiency.
[0041]
Furthermore, in the centrifugal centrifugal pump 10 according to the present embodiment, in addition to the knowledge that the difference between the flow velocity of the liquid near the outlet 28 and the flow velocity in the centrifugal pump chamber 32 is approximated as described above, If the outflow amount to the chamber 32 differs greatly between the impellers 24, the rotation of the impeller 24 is not constant and energy loss occurs, and the outflow amount from the arc pump chamber 30 to the spiral pump chamber 32 varies between the impellers 24. If it is small, the energy loss is reduced. However, on the other hand, based on the knowledge that a flow between the centrifugal pump chamber 32 and the arc pump chamber 30 is generated and a new energy loss is generated, the outlet width of the centrifugal pump chamber 32 (that is, , The opening width of the outlet 28) was set to a certain fixed area.
[0042]
That is, 0.15 <{(R−r) / r} <0, where R is the radius of the volute casing 36 at the volute winding end position B and r is the radius of the arc casing 34 of the arc pump chamber 30. .3 relationship was established.
[0043]
As a result, the difference in the outflow amount from the arc pump chamber 30 to the spiral pump chamber 32 between the impellers 24 is small, and an unnecessary flow does not occur between the spiral pump chamber 32 and the arc pump chamber 30 (energy loss is reduced). The pump efficiency can be maximized as long as it does not occur.
[0044]
Here, FIG. 4 shows data obtained by experiment on the correspondence between {(R−r) / r} and pump efficiency, and FIG. 5 shows the {(R−r) / R} and the pump efficiency (data shown in FIG. 4) are shown in the graph. In FIG. 5, line X is an example of a centrifugal pump having a capacity of 300 cc / 10 s, and line Y is an example of a centrifugal pump having a capacity of 400 cc / 10 s.
[0045]
As is clear from FIGS. 4 and 5, it can be seen that the pump efficiency is high in a range where the relationship of 0.15 <{(R−r) / r} <0.3 is established. In particular, when {(R−r) / r} is set in a range of “0.18 to 0.22”, it can be confirmed that the pump efficiency is the highest.
[0046]
Thus, in the centrifugal centrifugal pump 10 according to the present embodiment, the radius of the volute casing part 36 at the volute winding end position B of the spiral pump chamber 32 with respect to the radius r of the arc casing part 34 of the arc pump chamber 30. By suitably setting the value of R, it is possible to make the region extremely effective in terms of energy loss, and it is possible to send out the liquid with the maximum pump efficiency.
[0047]
Further, the centrifugal centrifugal pump 10 according to the present embodiment has a simple structure including the arc pump chamber 30 (arc casing portion 34) and the spiral pump chamber 32 (volute casing portion 36), and also has a simple shape. Therefore, the manufacture is easy and the cost is low, and the number of parts does not increase.
[0048]
As described above, in the centrifugal centrifugal pump 10 according to the present embodiment, the liquid energized by the impeller 24 is unlikely to flow from the spiral pump chamber 32 toward the center of the impeller 24. The liquid to which energy (the action of centrifugal force) is applied from the impeller 24 does not flow into the centrifugal pump chamber 32 at a stretch, and the flow velocity does not become excessively fast, and the difference from the liquid flow velocity in the vicinity of the outlet 28 is reduced. The loss can be greatly reduced and the pump efficiency can be increased, and this can be realized easily and at a low cost without increasing the number of parts with a simple structure.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an overall configuration of a centrifugal centrifugal pump according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a configuration of a pump unit of the centrifugal centrifugal pump according to the embodiment of the present invention.
FIG. 3 is a diagram showing a correspondence relationship between a winding angle of a centrifugal pump chamber of the centrifugal centrifugal pump according to the embodiment of the present invention and pump efficiency.
FIG. 4 is data obtained by experiments showing a correspondence relationship between a predetermined value of the radius R of the volute casing portion at the end of volute winding in the centrifugal pump chamber and the pump efficiency in the centrifugal centrifugal pump according to the embodiment of the present invention. It is a correspondence chart shown.
FIG. 5 is a diagram showing the data shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Centrifugal centrifugal pump 10A Motor part 10B Pump part 12 Housing 24 Impeller 28 Outlet (discharge port)
30 Arc pump chamber 32 Spiral pump chamber 34 Arc casing part 36 Volute casing part A Volute winding start position θ Winding angle

Claims (1)

In centrifugal centrifugal pumps that discharge liquid from the discharge port by rotating the impeller,
An arc pump chamber constituted by an arc casing formed concentrically with the impeller;
The arc pump chamber is continuously provided spirally from the arc pump chamber to the discharge port on the downstream side in the impeller rotation direction, and the circumferential end portion on the downstream side in the impeller rotation direction of the arc pump chamber is wound by volute. A spiral pump chamber configured by a volute casing which is set as a start position and a circumferential end on the upstream side in the impeller rotation direction of the arc pump chamber is set as a volute winding end position;
With
Setting the volute winding start position of the volute casing such that the winding angle from the volute winding start position to the volute winding end position of the spiral pump chamber is 115 degrees or more and less than 185 degrees, and
When the radius of the volute casing of the spiral pump chamber at the end of volute winding is R and the radius of the arc casing of the arc pump chamber is r, 0.15 <{(R−r) / r} <0. Set so that the relationship of 3
Centrifugal centrifugal pump characterized by that.

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