JP3204686U - Pump and mold temperature control apparatus having the same - Google Patents

Abstract

A pump capable of reducing harsh sounds without changing the number of rotations and a mold temperature control apparatus including the pump are provided. SOLUTION: A plurality of blade pieces 24 are provided at an outer peripheral portion at intervals in a circumferential direction in a casing 10 provided with a partitioning portion 17 so as to partition a suction port side and a discharge port side of a flow path 14. The impeller 20 is rotatably provided with the impeller 20. The impeller is obtained by multiplying the number of blade pieces by the number of rotations per second when the impeller 20 is rotated by a motor 30 driven at a power supply frequency. The fundamental frequency is set to a value of 3.5 kHz to 6.0 kHz. [Selection] Figure 1

Description

  The present invention relates to a pump provided with an impeller so as to be rotatable, and a mold temperature control apparatus including the pump.

  Conventionally, various pumps have been known as pumps for sucking and discharging fluid. However, a pump with a small flow rate and a high head may be desired. As such a pump, a plurality of blade pieces are provided on the outer peripheral portion at intervals in the circumferential direction in a casing provided with a partition so as to partition the suction port side and the discharge port side of the flow path. A so-called overflow pump (also referred to as a cascade pump or a regenerative pump) in which an impeller (impeller) is rotatably provided is known (see, for example, Patent Document 1 and Patent Document 2 below).

JP-A-9-68184 JP 2000-205166 A

  In such a pump, by rotating the impeller, the pressure of the fluid sucked from the suction port is increased in the process of reaching the discharge port, but the blade piece that moves with the rotation of the impeller is the discharge port of the partition part. Since the pressure periodically rises every time it is located in the vicinity, there is a problem that annoying high-frequency noise is likely to occur. Although it is conceivable to change the rotation speed in order to suppress such noise, the pump performance changes due to the change in the rotation speed, so further improvement is desired.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pump that can reduce annoying sound without changing the number of revolutions, and a mold temperature control apparatus including the pump.

  In order to achieve the above object, a pump according to the present invention has a plurality of blade pieces around the outer periphery in a casing provided with a partition so as to partition the suction port side and the discharge port side of the flow path. A pump in which an impeller provided at intervals in a direction is rotatably provided, wherein the impeller is rotated at a number of rotations per second when rotated by a motor driven at a power frequency. The fundamental frequency obtained by multiplying by is configured to have a value of 3.5 kHz to 6.0 kHz.

  In order to achieve the above object, a mold temperature control device according to the present invention includes a storage unit that stores a temperature control medium, and a temperature control medium in the storage unit that is sent to a medium flow path provided in the mold. And a pump according to the present invention.

  Since the pump according to the present invention and the mold temperature control apparatus including the pump are configured as described above, it is possible to reduce annoying sound without changing the rotation speed.

(A)-(c) shows typically an example of the pump concerning one embodiment of the present invention, and (a) is a part corresponding to X1-X1 line arrow in Drawing 2 (b) generally. (B) is a partially broken schematic plan view in which a part corresponding to the YY arrow view in (a) is omitted, and (c) is (b). It is a partially broken schematic longitudinal cross-sectional view corresponding to the X2-X2 line arrow in FIG. (A) is a partially omitted schematic front view of the pump, and (b) is a partially omitted schematic side view of the pump. It is a schematic system block diagram which shows typically an example of the mold temperature control system incorporating an example of the mold temperature control apparatus which concerns on one Embodiment of this invention provided with the pump. (A) is a partially broken schematic longitudinal sectional view corresponding to FIG. 1 (a) schematically showing an example of a pump of a comparative example, and (b) is an example of the pump according to the present invention and the comparative example. It is a table | surface which shows the result of sensory evaluation at the time of driving. (A) is a graph which shows typically the analysis result of the pump of the Example, (b) is a graph which shows typically the analysis result of the pump of the comparative example.

Embodiments of the present invention will be described below with reference to the drawings.
1-3 is a figure which shows typically an example of the pump which concerns on this embodiment, and a metal mold | die temperature control apparatus provided with the same.
In FIG. 3, pipes (piping) or the like, which are paths through which the medium or the like passes, are schematically shown by solid lines and wavy lines.

As shown in FIGS. 1 and 2, the pump 3 according to the present embodiment is provided in the casing 10 provided with the partition portion 17 so as to partition the suction port 11 side and the discharge port 19 side of the flow path 14. An impeller (impeller) 20 in which a plurality of blade pieces 24 are provided on the outer peripheral portion 22 at intervals in the circumferential direction is rotatably provided.
As shown in FIG. 3, the mold temperature control apparatus 1 according to the present embodiment includes a storage unit 2 that stores a temperature control medium, and a medium flow path in which the temperature control medium of the storage unit 2 is provided in the mold 7. 8 and the pump 3 according to this embodiment. In addition, the suction side of the pump 3 and the medium (pump 3) side of the storage unit 2 are connected via a connection path 4. Further, a delivery path 5 connected to the medium flow path 8 of the mold 7 is connected to the discharge side of the pump 3, and the medium of the mold 7 is connected to the return medium (mold 7) side of the storage unit 2. A return medium path 6 connected to the flow path 8 is connected.

The mold 7 has, for example, a configuration having a fixed mold and a movable mold, and the fixed mold and the movable mold are respectively provided with medium flow passages 8 and 8 for circulating the temperature control medium. . The medium flow path 5 is connected to the inlet (medium connection port) side of the medium flow paths 8 and 8, and the return path 6 is connected to the outlet (return medium connection port) side of the medium flow paths 8 and 8. Connected.
The medium feeding path 5 and the inlets of the medium flow paths 8 and 8 are a flexible manifold such as a manifold section that branches the single medium feeding path 5 into a plurality of parts, or a hose or a tube connected to a plurality of connection ports of the manifold section. It is good also as a structure connected through the piping material which has property. Further, a configuration may be adopted in which a medium sending valve that allows or blocks the passage of the temperature control medium sent toward the medium flow path 8 may be provided at an appropriate place such as a manifold part or a pipe line.
In addition, in a similar manner to the outlets of the return medium path 6 and the medium flow paths 8 and 8, a manifold section for branching the single return path 6 into a plurality of hoses and tubes connected to a plurality of connection ports of the manifold section, etc. It is good also as a structure connected through the piping material which has this flexibility. Alternatively, a return valve that allows or blocks the passage of the temperature control medium returned from the medium flow path 8 may be provided at an appropriate place such as a manifold part or a pipe line.

In addition, it is good also as a structure which provided the temperature sensor as a detection means which detects the temperature of the metal mold | die 7 in an appropriate place. For example, the temperature sensor may be embedded in the mold 7 or may be provided in the outlet side portion of the medium flow passage 8 or in the return passage 6 in the vicinity of the outlet.
Further, as a molding machine for the mold 7, a synthetic resin as a material melted by a cylinder or the like is injected into a cavity or the like formed by the fixed mold and the movable mold of the mold 7 from a nozzle or the like. In addition, an injection molding machine or the like that sequentially molds the molded product may be used, or another molding machine such as a compression molding machine may be used. Moreover, as a molding material, it is good also as a fiber reinforced synthetic resin material etc. which made the synthetic resin material contain reinforcing fibers, such as carbon fiber and glass fiber.

Further, the mold temperature adjusting device 1 circulates the temperature adjusting medium adjusted so as to have a preset temperature in the storage unit 2 to the medium flow path 8 via the medium feeding path 5 and the medium returning path 6. It is set as the structure supplied to.
A temperature sensor that detects the temperature of the temperature control medium supplied toward the mold 7 and a discharge pressure of the pump 3 are detected at appropriate positions such as the medium transmission path 5, the connection path 4, and the connection pipe line of the pump 3. A pressure gauge or the like is provided. In addition, it is good also as a structure which connected the transmission path 5 and the return path 6 or the storage part 2 by the bypass path provided with the bypass valve.
The storage unit 2 constitutes a medium tank that stores the temperature control medium, and is in principle filled with the temperature control medium and at a full level while the mold temperature control device 1 is in operation. Although not shown in the drawing, the storage unit 2 supplies (supplements) the temperature control medium to the storage unit 2 and the discharge path discharges (overflows) the temperature control medium from the storage unit 2. Etc. are connected.

  Further, the storage unit 2 is provided with a heater as a heating means for heating the temperature control medium, a cooling path as a cooling means for cooling the temperature control medium, a level meter for detecting a decrease in the medium level, and the like. As a cooling means of the storage unit 2, a direct cooling type in which a cooling path for supplying a temperature control medium as a cooling medium directly to the temperature control medium in the storage unit 2 may be provided, or in the storage unit 2 Alternatively, an indirect cooling type in which a cooling path for indirectly cooling a temperature control medium flowing through a pipe connected to the storage unit 2 may be used. Further, a configuration in which both direct cooling and indirect cooling are possible, and a configuration in which direct cooling or indirect cooling can be selected according to the set temperature of the temperature control medium or the like may be used. Further, the storage unit 2 is provided with a drain (drain valve) for discharging the temperature control medium in the storage unit 2, a thermostat for preventing overheating, and the like. Moreover, it is good also as a structure which provided the open | release relief valve (safety valve) etc. which prevent the abnormal rise of the pressure in the system | strain containing the storage part 2 etc. in the storage part 2 or a suitable place.

Although not shown, the mold temperature control device 1 includes a CPU or the like at an appropriate position and is connected to each device of the mold temperature control device 1 via a signal line or the like to control each device. A control unit is provided. In addition, a display operation unit that configures a display unit and an operation unit that are connected to the control unit via a signal line or the like to set, input, and display various settings, and the display operation unit. The setting conditions and input values, various programs, various operating conditions set in advance, various data tables, and the like set and input by the above operation are stored, and a storage unit composed of various memories and the like is provided.
In the mold temperature control apparatus 1, based on the temperature detected by a temperature sensor that detects the temperature of the temperature control medium, the heater is controlled by energizing the heater so that the temperature control medium has a preset temperature set in advance. It is good also as a structure by which the cooling control by heating control and supply control of the cooling medium to a cooling path is performed by a control part.

  In addition, as a temperature control medium, water (fresh water) may be sufficient and other media, such as an oil system, may be sufficient. In addition, when the temperature control medium is water (fresh water) and it is necessary to heat to a temperature higher than the boiling point of normal pressure, the system is adjusted so that the temperature control medium does not boil according to the temperature. The pressure may be maintained. Further, when the cooling medium is water, the supply source may be a cooling tower or the like installed in a factory or the like. In addition, the cooling medium may be temperature-controlled by an appropriate chiller or the like, and in the case of indirect cooling (heat exchange) type, ethanol, other alcohols, other cooling It may be a medium.

As shown in FIGS. 1A and 2, the pump 3 includes a casing 10 that rotatably accommodates the impeller 20 and a motor 30 that rotates the impeller 20, and is a so-called overflow pump (cascade pump). Or a regenerative pump). The pump 3 is configured such that when the motor 30 is started, the impeller 20 is rotated, and the temperature adjusting medium as the fluid sucked from the suction port 11 side is discharged from the discharge port 19 side.
The casing 10 is formed so as to define a housing chamber 13 that houses the impeller 20, and is substantially cylindrical when viewed in the axis (rotary shaft 31) direction of the impeller 20 so as to correspond to the substantially disk-shaped impeller 20. It is said that. The casing 10 may include a substantially cylindrical casing body that opens in one axial direction and a lid that covers the opening of the casing body.

Moreover, the flow path 14 of the casing 10 is provided in the circular arc shape so that the outer peripheral part 22 of the impeller 20 may be followed, as shown to Fig.1 (a). As shown in FIG. 1 (c), the flow path 14 is provided so as to be continuous with the inner peripheral surface 15 facing the axial center side (radially inner side) and both axial sides of the inner peripheral surface 15, and face each other. The inner surface is divided into two axially inner surfaces facing in the axial direction, and an outwardly facing surface 16 which is provided so as to be connected to the axial center side of the inner surfaces on both axial sides and which faces the radially outer side on the inner peripheral surface 15 side. Yes. In other words, the flow path 14 is configured such that two arc-shaped grooves that open in the axial direction face each other.
The inner peripheral surface 15 that defines the flow path 14 is formed in an arc shape with the rotary shaft 31 as a circle center so that a clearance gap is formed between the inner peripheral surface 15 and the outer peripheral end surface of the impeller 20. In addition, in the illustrated example, the inner surfaces on both sides in the axial direction that define the flow path 14 are parallel to each other, but inclined surfaces (tapered surfaces) that approach (or move away from) each other toward the axial center side. ) Shape.

The outward surface 16 that divides the flow path 14 is provided so as to be substantially in the radial direction at the base end portion (end portion on the axial center side) of the blade piece 24 provided on the outer peripheral portion 22 of the impeller 20 described later. It has been. Note that the corners of the inner peripheral surface 15, the axially inner surfaces, and the outward surface 16 that define the flow path 14 may have an R surface shape, a C surface shape, or the like.
The casing 10 is provided with a suction passage 12 and a discharge passage 18 so as to open on the inner peripheral surface 15. The suction passage 12 and the discharge passage 18 are provided so as to penetrate through the side peripheral wall portion constituting the inner peripheral surface 15. Further, the suction passage 12 and the discharge passage 18 are provided so as to extend generally outward in the radial direction, and so that the openings on the flow passage 14 side are opened at positions spaced apart in the circumferential direction. The distance in the circumferential direction between the opening on the flow path 14 side of the suction path 12 and the opening on the flow path 14 side of the discharge path 18 is appropriately determined from the viewpoint of partitioning the suction path 12 side and the discharge path 18 side of the flow path 14. It is good also as an interval of. The intervals in the circumferential direction between the openings on the flow path 14 side of the suction path 12 and the discharge path 18 are, for example, imaginary lines connecting the centers of the openings on the flow path 14 side of the suction path 12 and the discharge path 18 and the axis. The angle formed may be about 20 degrees to 100 degrees. In the example shown in the figure, the angle formed is about 60 degrees.

As shown in FIG. 2A, the opening on the side opposite to the flow path of the suction path 12 is a suction port 11, and in the illustrated example, a connection port that opens in the axial direction is configured. A connection path 4 connected to the medium sending side of the storage unit 2 is connected to the suction port 11. The opening on the side opposite to the flow path of the discharge path 18 is a discharge port 19, and in the illustrated example, a connection port that opens in the axial direction is configured. The medium delivery path 5 connected to the medium flow path 8 is connected to the discharge port 19. Further, in the illustrated example, the suction port 11 and the discharge port 19 are shown in a circular shape when viewed in the opening direction. Note that the suction passage 12 and the discharge passage 18 may be substantially rectangular when viewed in the longitudinal direction of the pipe.
A partition 17 is provided so as to partition the openings on the flow path 14 side of the suction path 12 and the discharge path 18. The partition portion 17 is provided so as to partition the flow path 14 having a configuration in which the arc-shaped grooves face each other as described above. Moreover, this partition part 17 is provided so that it may adjoin to both axial direction both surfaces of the outer peripheral part 22 of the impeller 22 so that an arc-shaped groove may not be formed. The partition portion 17 is provided so as to protrude outward in the radial direction from the outward surface 16 and so as to approach or abut against the inner peripheral surface 15 between the openings on the flow path 14 side of the suction passage 12 and the discharge passage 18. It has been. Moreover, the dimension along the circumferential direction of the partition portion 17 is a dimension corresponding to the circumferential interval between the openings on the flow path 14 side of the suction path 12 and the discharge path 18 described above.

Further, on at least one side of the casing 10 in the axial direction, a bearing portion that rotatably holds the rotating shaft 31 of the impeller 20 and the temperature adjusting medium flowing out from the bearing portion to the axially outer side (motor 30 side) are allowed to flow. A seal portion such as a mechanical seal to be suppressed is provided. Further, the output shaft of the motor 30 and the rotary shaft 31 may be provided integrally or coaxially via an appropriate joint, or may be connected via an appropriate gear or the like.
In addition, the shape of the flow path 14 of the casing 10, the partition part 17, the suction path 12, and the discharge path 18, the opening direction of the suction inlet 11 and the discharge outlet 19, etc. are not restricted to what is illustrated, and various deformation | transformation is possible. Is possible.

The impeller 20 has a configuration in which a shaft insertion hole 21 through which the rotation shaft 31 is inserted is provided in a central portion viewed in the axial direction. In the illustrated example, the shaft insertion hole 21 is shown as a key hole provided with a groove portion that opens toward the axial center with which the key portion provided on the rotating shaft 31 engages.
In addition, the dimension along the axial direction of the central portion where the shaft insertion hole 21 of the impeller 20 is provided is made larger than the dimension along the axial direction of the outer peripheral portion of the central portion including the outer peripheral portion 22. In addition, an annular portion having a small dimension along the axial direction is formed between the central portion and the outer peripheral portion 22 provided with the blade pieces 24 so as to be stepped down from both axial sides of the outer peripheral portion 22. The configuration is provided.
The impeller 20 and the casing 10 may be made of a metal material such as a copper alloy, stainless steel, aluminum, or iron, or a hard synthetic resin material such as a fiber-reinforced synthetic resin material.

The impeller 20 has a basic frequency of 3.5 kHz to 6.0 kHz obtained by multiplying the number of blade pieces 24 by the number of rotations per second (rps) when rotated by the motor 30 driven at the power frequency. It is comprised so that it may become the value of. That is, the rotation speed (synchronous speed) per minute of the motor (three-phase induction motor) 30 having two poles under the power supply frequency of 60 Hz is 3600 rpm (rotation speed per second is 60 rps), and the basic frequency The number of blade pieces 24 having a value of 3.5 kHz to 6.0 kHz is 59 to 100. Preferably, the number of blade pieces 24 having a fundamental frequency of 4.0 kHz or more, that is, 67 or more may be used.
Similarly, the number of revolutions (synchronous speed) per minute of a motor (three-phase induction motor) 30 with two poles under a power supply frequency of 50 Hz is 3000 rpm (the number of revolutions per second is 50 rps). The number of blade pieces 24 having a fundamental frequency of 3.5 kHz to 6.0 kHz is 70 to 120. Preferably, the number of blade pieces 24 having a fundamental frequency of 4.0 kHz or more, that is, 80 or more may be used.
Note that the rotation speed (rpm) per minute of the motor 30 can be grasped as a rated rotation speed in consideration of slipping. In this case, the number of blade pieces 24 tends to be larger than the above range. In the above description, the number of rotations per minute of the motor 30 having two poles is exemplified, but can be calculated as appropriate according to the number of poles of the motor 30.

If the number of blades 24 of the impeller 20 is reduced too much, the fundamental frequency that becomes the peak frequency and the frequency (overtone) component obtained by multiplying the fundamental frequency by an integer (natural number) are the frequencies that are most audible from the auditory curve (equal loudness curve). There is a tendency for a plurality of peak frequencies to appear between 2 kHz to 6 kHz, which is a frequency band near 3 kHz, which is a band, and which is a frequency band that is easy to hear from the audibility curve (equal loudness curve). On the other hand, if the number of the blade pieces 24 of the impeller 20 is increased too much, the ability of the pump 3 itself is lowered, or the blade pieces 24 need to be thinned, so that the strength tends to be lowered.
In this embodiment, the number of poles of the motor 30 is set to 2, and the number of blade pieces 24 of the impeller 20 is set to 70 to 90 so as to cope with such a viewpoint and a difference in power supply frequency. Further, from the viewpoint of design and molding, the number of blade pieces 24 of the impeller 20 may be a value obtained by dividing 360 degrees by a natural number, for example, 60 sheets, 72 sheets, 90 sheets, 120 sheets, and the like. In the present embodiment, the number of blade pieces 24 of the impeller 20 is set to 72, which is particularly preferable when the power supply frequency is 60 Hz, that is, the number of the basic frequency is about 4.32 kHz.

In the present embodiment, a plurality of blade pieces 24 and 27 are provided on both sides in the axial direction of the outer peripheral portion 22 of the impeller 20 at intervals in the circumferential direction.
Further, the blade pieces 24 and 27 on both sides in the axial direction are provided at equal intervals in the circumferential direction. In addition, each of the blade pieces 24 and 27 on both sides in the axial direction has a configuration in which the thickness direction is along the circumferential direction, that is, a configuration that protrudes in the axial direction. Moreover, the thickness dimension along the circumferential direction of each blade piece 24 and 27 of these axial direction both sides is made into the same thickness, respectively. In addition, the blade pieces 24 and 27 on both sides in the axial direction are provided so as to extend radially with the rotating shaft 31 as a center. That is, the adjacent blade pieces 24, 24, 27, 27 are arranged so as to be separated from each other toward the radially outer side, that is, so as to expand toward the radially outer side.

Further, the number of blade pieces 24 in the one axial side portion 23 and the number of blade pieces 27 in the other axial side portion 26 are the same. That is, 72 blade pieces 24 and 27 are provided on both sides in the axial direction. That is, the axial direction of the outer peripheral portion 22 of the impeller 20 is set so that the angle (opening angle) θ1 formed by imaginary lines passing through the thickness direction center lines of the adjacent blade pieces 24, 24, 27, 27 is 5 degrees. The blade pieces 24 and 27 are provided on both sides.
Further, in the present embodiment, the blade piece 24 of the one axial side portion 23 and the blade piece 27 of the other axial side portion 26 are provided so as to be shifted by 1/2 pitch in the circumferential direction. . That is, when viewed in the axial direction, the blade of the other side portion 26 (23) is centered in the circumferential direction between the adjacent blade pieces 24, 24 (27, 27) of the one side portion 23 (26) on both sides in the axial direction. The blade pieces 24 and 27 are provided on both axial sides of the outer peripheral portion 22 of the impeller 20 so that the pieces 27 (24) are positioned.

Further, between the adjacent blade pieces 24, 24, 27, 27 on both sides in the axial direction are groove portions 25, 28 for receiving a temperature control medium as a fluid. The blade pieces 24 and 27 and the groove portions 25 and 28 on both sides in the axial direction have the same configuration so as to be symmetrical in the axial direction, except for a configuration shifted by ½ pitch in the circumferential direction.
In the present embodiment, notched groove portions 25 and 28 are formed in which the blade pieces 24 and 27 on both sides in the axial direction are opened on both sides in the axial direction of the outer peripheral portion 22 of the impeller 20 toward the outside in the axial direction and the radial direction. It is set as the structure provided. In other words, the groove portions 25 and 28 are provided so that the blade pieces 24 and 27 remain. The number of the blade pieces 24 and 27 is synonymous with the number of the groove portions 25 and 28 on both axial sides. That is, the number of the blade pieces 24 and 27 is grasped as the number of the groove portions 25 and 28. You can also. The depth dimension along the axial direction of these groove portions 25 and 28, the width dimension along the circumferential direction, the thickness dimension of the blade pieces 24 and 27, etc. are in terms of the strength of the impeller 20, the discharge amount (flow rate), the lift, etc. It can be set as appropriate from the viewpoint of suppressing a decrease in the capacity of the pump 3.

  Further, in the illustrated example, the blade pieces 24 and 27 on both sides in the axial direction are provided in a substantially half portion on the radially outer side of the outer peripheral portion 22 whose dimension along the axial direction is larger than the annular portion of the impeller 20. In the example, both end surfaces in the axial direction of the blade pieces 24 and 27 are flush with both axial surfaces on the radially inner side of the outer peripheral portion 22. Further, the outer peripheral side end faces of the blade pieces 24 and 27 facing outward in the radial direction are provided in parallel to the inner peripheral face 15. In addition, the entire blade pieces 24 and 27 provided on the radially outer side of the outer peripheral portion 22 are positioned in the flow path 14 in the radial direction, and the boundary portion between the outer peripheral portion 22 and the radially inner side is the radial direction. Thus, the configuration is such that the position substantially coincides with the outward surface 16. Further, projecting step portions formed so as to protrude in directions facing each other so as to partition the flow path 14 of the casing 10 are arranged close to each other on both axial sides inside the outer peripheral portion 22 in the radial direction. . In addition, the groove portions 25 and 28 are provided so that the depth dimension along the axial direction increases toward the radially outer side. In the illustrated example, the groove bottom surface facing the axially outer side of the groove portions 25 and 28 is shown as a concave curved surface. The shapes of the groove portions 25 and 28 and the blade pieces 24 and 27 are not limited to those shown in the drawings, and various modifications are possible.

Since the pump 3 according to the present embodiment and the mold temperature control apparatus 1 including the pump 3 are configured as described above, it is possible to reduce annoying sound without changing the rotation speed.
That is, the basic frequency obtained by multiplying the number of blade pieces 24 and 27 by the number of rotations per second when the impeller 20 of the pump 3 is rotated by the motor 30 driven at the power supply frequency is 3.5 kHz to 6. It is configured to have a value of 0.0 kHz. Therefore, the fundamental frequency that is the peak frequency and the frequency (overtone) component obtained by multiplying the fundamental frequency by an integer do not have a value near 3 kHz that is the frequency band that is most easily audible from the audibility curve (equal loudness curve). Since a plurality of peak frequencies do not appear between 2 kHz and 6 kHz, which is a frequency band that is easy to hear from (equal loudness curve), it is possible to effectively reduce harsh sounds. Further, since the number of peak frequencies in the audible range (about 20 Hz to 20 kHz) is reduced compared to the configuration in which the impeller 20 is configured so that the fundamental frequency is lower than the above range, an harsh sound can be effectively obtained. Can be reduced. Moreover, compared with what comprised the impeller 20 so that a fundamental frequency might become a value higher than the said range, the fall of the capability of the pump 3, the strength fall, etc. by the increase in the number of the blade pieces 24 and 27 can be suppressed. . Moreover, compared with what suppresses noise by changing a rotation speed, the capability change of the pump 3, the overload of the pump 3 (motor 30), etc. can be suppressed.

  In the present embodiment, the number of poles of the motor 30 is 2, and the number of blade pieces 24 and 27 of the impeller 20 is 70 to 90. Therefore, regardless of whether the power supply frequency is 50 Hz or 60 Hz, the basic frequency becomes a value of 3.5 kHz to 6.0 kHz, so that parts can be shared and versatility can be improved. Moreover, by setting it as 90 sheets or less, the fall of the pump capability by the increase in the number of the blade pieces 24 and 27, a strength fall, etc. can be suppressed more effectively. In addition, in any case where the power supply frequency is 50 Hz or 60 Hz, the number of blade pieces 24 and 27 is not limited to the common impeller 20 in which the number of blade pieces 24 and 27 is the same. You may make it apply the impeller 20 made into.

  Moreover, the mold temperature control apparatus 1 according to the present embodiment sends a storage unit 2 that stores the temperature control medium, and the temperature control medium of the storage unit 2 to the medium flow path 8 provided in the mold 7. And a pump 3. Therefore, the temperature control medium can be effectively delivered to the medium flow path 8 of the mold 7 where the flow path tends to be relatively complicated. Moreover, it becomes the metal mold | die temperature control apparatus 1 which can reduce an unpleasant sound as mentioned above. In addition, the pump 3 which concerns on this embodiment is not restricted to the aspect integrated in the metal mold | die temperature control apparatus 1, In addition, it is applicable as what transfers various fluids.

  In the present embodiment, the same number of blade pieces 24 and 27 are provided at equal intervals on both sides of the impeller 20 in the axial direction, and the blade pieces 24 and 27 on both sides in the axial direction are shifted from each other by ½ pitch. Although an example in which the position is provided is shown, the present invention is not limited to such a mode. For example, the blade pieces 24 and 27 on both sides in the axial direction may be provided at positions shifted by a pitch different from ½ pitch, or may be provided so as to overlap when viewed in the axial direction. Further, the number of blade pieces 24 and 27 on both sides in the axial direction of the impeller 20 may be made different or may be provided at unequal intervals. In this case, the maximum pitch in the circumferential direction between adjacent blade pieces 24, 24, 27, and 27 is not more than three times the minimum pitch, preferably 1 to prevent the blade pieces 24 and 27 from being extremely unevenly distributed in the circumferential direction. You may make it set suitably so that it may become about 5 times or less. Moreover, it is good also as an aspect etc. which provided the blade piece 24 only in the axial direction one side instead of the aspect which provided the blade piece 24,27 in the axial direction both sides of the impeller 20. FIG.

Next, an example of a pump according to the present invention and a comparative example will be described with reference to FIGS.
The Example employ | adopted the pump 3 which concerns on the said embodiment, ie, the impeller 20 with the said structure. In the comparative example, as shown in FIG. 4A, the number of the blade pieces 24 of the impeller 20A is 45 pumps 3A in which the number is smaller than that of the embodiment. That is, the pump 3A of the comparative example is provided on the outer peripheral portion 22A of the impeller 20A so that the angle (opening angle) θ2 formed by the imaginary lines passing through the thickness direction center lines of the adjacent blade pieces 24, 24 is 8 degrees. The blade piece 24 is provided. That is, the width dimension along the circumferential direction of the groove 25A defined by the blade pieces 24, 24 is larger than that of the embodiment. In FIG. 4A, only the one axial side portion 23A of the impeller 20A is shown, but the other axial side portion also has a position shifted by 1/2 pitch as in the above embodiment. In addition, 45 blade pieces are provided. Further, the pump 3 of the embodiment and the pump 3A of the comparative example have the same configuration except for the number of blade pieces 24, 24, 27, 27 of the impellers 20, 20A.

The pumps 3 and 3A configured as described above are incorporated in the mold temperature control device, and the pumps 3 and 3A are started to circulate the temperature control medium, and the sensory evaluation test and analysis using the FFT analyzer are performed as follows. And went. 5 (a) and 5 (b) show the results of frequency characteristic analysis in the sampling time zone, schematically showing the sound pressure on the vertical axis and the frequency on the horizontal axis.
In the sensory evaluation test, sound evaluation during driving of the mold temperature control apparatus incorporating the pumps 3 and 3A of Examples and Comparative Examples was performed with four men and women as subjects. As a result, as shown in FIG. 4 (b), 7 out of 8 people were more worried about the harsh sounds and metal sounds in the comparative example than in the example.

  The analysis using the FFT analyzer was carried out by measuring the drive sound of the mold temperature control apparatus incorporating the pumps 3 and 3A of the examples and comparative examples using a sound level meter (sound level meter manufactured by YOKOGAWA: 3607). The analysis was performed using an analyzer (portable dual channel FFT analyzer: CF360 manufactured by Ono Sokki Co., Ltd.). As a result, in the example, as shown in FIG. 5A, the peak of the fundamental frequency appears in the vicinity of slightly above 4 kHz, and thereafter, the vicinity of slightly above 8 kHz, which is approximately every 4 kHz, and slightly above 12 kHz. As a result, overtone peaks appear in the vicinity and in the vicinity of slightly above 16 kHz. In FIG. 5A, the fact that the waveform does not appear after exceeding 16 kHz is assumed that the sound pressure is below -80 dB.

  On the other hand, in the comparative example, as shown in FIG. 5B, the peak of the fundamental frequency appears in the vicinity of slightly above 2.5 kHz, and the peak of harmonics appears in the vicinity of approximately every 2.5 kHz thereafter. became. Also from this result, it is shown that the number of peak frequencies in the audible range (about 20 Hz to 20 kHz) is smaller in the embodiment than in the comparative example, and the vicinity of 3 kHz (2. It was shown that no peak appeared at 5 kHz to 3.5 kHz), and that it was possible to reduce harsh sounds. Also, in the example, compared with the comparative example, the discharge amount was practically no problem in the lift range required when applied to the mold temperature controller.

DESCRIPTION OF SYMBOLS 1 Mold temperature control apparatus 2 Storage part 3 Pump 10 Casing 11 Suction inlet 14 Flow path 17 Partition part 19 Outlet 20 Impeller 22 Outer peripheral part 24,27 Blade piece 30 Motor 7 Mold 8 Medium flow path

Claims (3)

An impeller having a plurality of blade pieces spaced apart in the circumferential direction is rotatably provided in a casing provided with a partition so as to partition the suction port side and the discharge port side of the flow path. A pump,
The impeller has a fundamental frequency obtained by multiplying the number of blade pieces by the number of rotations per second when it is rotated by a motor driven at a power supply frequency, and has a value of 3.5 kHz to 6.0 kHz. A pump characterized by comprising. In claim 1,
The number of poles of the motor is 2, and the number of blade pieces of the impeller is 70 to 90.   A storage unit that stores a temperature control medium, and the pump according to claim 1 or 2 that sends the temperature control medium of the storage unit to a medium flow path provided in a mold. Mold temperature control device.

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