JPH0615875B2 - Centrifugal blower impeller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an impeller of a centrifugal blower, and more particularly, to an improvement of an impeller in which a blade, a core plate and a side plate are integrally formed.

[Prior Art] An impeller of a centrifugal blower is disclosed in, for example, JP-A-53-1342.
As disclosed in Japanese Patent Laid-Open No. 08-134209 and Japanese Patent Application Laid-Open No. 53-134209, a side plate, a core plate having an outer diameter larger than the inner diameter of the side plate, and a core plate are disposed at the center of the core plate and fitted to a rotary shaft. A boss having a hole for cutting and a vane located on one circle and tilted at an angle with respect to the radial line of the circle and arranged between the mandrel and the side plate and connected thereto. It is provided such that when it rotates, fluid is guided from the central opening in the side plate to the vane, is subjected to pressure by the vane, and is discharged from between the side plate and the mandrel.

Such an impeller is generally manufactured by separately manufacturing the blade, the core plate and the side plate and assembling them. However, variations in assembly accuracy cannot be avoided,
Not only the dimensional accuracy and mechanical strength are low, but because there are many unbalances with different sizes, positions and angles, it is necessary to adjust the dynamic balance after assembling, and the joining is weak due to aging. There is also a risk of decomposition. For this reason, it has been proposed to integrally mold a part of the synthetic grease and join the resin-molded remainder, or integrally mold the whole of the synthetic resin. For example, in Japanese Utility Model Publication No. 57-89897,
There is described an impeller in which a core plate and blades are integrally formed, side plates are separately formed, and these are joined by a solvent or the like. Furthermore, Japanese Patent Publication No. 52-49569 and Japanese Utility Model Publication No. 54-1
In Japanese Patent No. 17508, the inner diameter of the side plate on the fluid inlet side is made larger than the outer diameter of the core plate on the fluid outlet side to provide blades,
An impeller in which a core plate and a side plate are integrally molded by two molds is described.

[Problems to be Solved by the Invention] Among these, the impeller integrally molded as a whole does not require adjustment of dynamic balance after assembly, and therefore can be manufactured at low cost, and moreover, it is possible to obtain dimensional accuracy and mechanical strength. It can be made high, but the outer diameter of the core plate must be smaller than the inner diameter of the side plate, which reduces the average outer diameter of the impeller, and the air volume is small for the size of the impeller. I can't get it. Increasing the number of rotations of the impeller can increase the air volume, but it also increases noise, so it is suitable for equipment that needs to be as quiet as possible, such as a ceiling-mounted unit in an air conditioner. It has the drawback of not being.

Furthermore, JP-A-53-134208 and JP-A-53-
An impeller for assembling the whole as described in Japanese Patent No. 134209, a part of which is integrally molded with synthetic resin, and the remaining resin-molded remainder is joined with an adhesive or the like. No. 57-89897 discloses that the assembled impeller has low dimensional accuracy and mechanical strength, and not only does it require an adjustment work of the dynamic balance after assembling, but the joint part is also changed by the secular change of the adhesive. There was a drawback that it was separated from the integrally molded body part.

Also, when a high-performance turbofan (centrifugal blower) having a shape in which one end of the side plate extends in the suction direction (axial direction) is integrally formed by the upper and lower mold halves, a sharp edge is formed on the mating surface of the mold. I knew it would be done.
The sharp edge has low mechanical strength, is easily deformed or damaged by the injection pressure of the resin during molding, or is apt to be deformed or damaged by the impact when the resin flows into the molding die, which shortens the life of the molding die.

An object of the present invention is an impeller whose side plate has a suction side portion extending in the axial direction and a bending portion smoothly curved in the radial direction from the suction side portion and extending in the discharge direction. The plate, blades and side plates can be integrally molded with a long-life molding die that is divided into two parts to form an impeller with good fluid performance, and it can be easily assembled with high precision, which allows dynamic balancing. The objective of the present invention is to obtain an impeller of a centrifugal blower that simplifies the adjustment, has a high mechanical strength, and can obtain a sufficient air volume without increasing the number of revolutions to achieve low noise.

[Means for Solving the Problems] In order to achieve the above object, a centrifugal blower of the present invention is formed integrally with a boss portion coupled to a rotating shaft, extends in the outer diameter direction, and has a counterflow to an outer peripheral edge portion thereof. A core plate having a protrusion protruding toward the road side, and a core plate integrally formed with the core plate and a side plate described later and arranged on a circle centered on the center of rotation and an outer diameter of the side plate from a position integrally formed with the core plate. A vane having a protruding portion extending outwardly to a position substantially equal to and a suction port formed integrally with the vane on the opposite side of the vane from the vane and having an inner diameter larger than the outer diameter of the vane and extending in the axial direction. A side plate having a bent portion that smoothly bends in the radial direction from the side portion and the suction side portion and extends in the discharge direction; and a side plate disposed on the inner peripheral side of the protrusion of the outer peripheral edge of the core plate and in the radial direction with the protrusion. Protrusions that engage with the protrusion of the blade And an auxiliary mandrel which is attached so as to engage with a portion in the circumferential direction and has an outer diameter substantially equal to the outer diameter of the side plate, and the mandrel,
The vanes and the side plates have two mating surfaces having a minimum diameter portion A of the side plate, a portion B on the vane axially distant from the minimum diameter portion A, and a line connecting the portion C on the outer peripheral side of the core plate. It is characterized by being integrally molded by a molding die.

[Operation] In the impeller of the present invention, the core plate, the blade, and the side plate connect the minimum diameter portion A of the side plate, the portion B on the blade separated from the portion A in the axial direction, and the portion C on the outer peripheral side of the core plate. It is manufactured by integrally molding two molds having mating surfaces associated with the lines, and the auxiliary mandrel is molded by another mold.

The obtained molded products have no dynamic imbalance, and the integrally molded product consisting of the core plate, the blade and the side plate is molded by the two molds having the mating surfaces as described above. No sharp edge is formed on the surface, and the edge has a thickness in the radial direction, which can significantly extend the life of the molding die and stabilize the accuracy over a long period of time, resulting in high quality. .

The impeller is made by joining such a dynamic unbalanced unitary molding and an auxiliary mandrel.

Assembling the auxiliary mandrel to the integrally molded product is performed by, for example, a mandrel,
Place the integrally molded product consisting of the blades and side plates on a table, etc., make the protrusions of the auxiliary mandrel contact the protrusions of the outer peripheral part of the mandrel, and place the auxiliary mandrel on the integrally molded part. This is done by joining the contact part of the blade and the contact part of the auxiliary core plate and the blade. At this time, when the auxiliary mandrel is placed on the integrally molded product, the protrusion of the auxiliary mandrel comes into contact with the inner peripheral side of the protrusion of the mandrel,
Since the center of the mandrel and the center of the auxiliary mandrel are automatically aligned, the adjustment of the dynamic balance after assembly is unnecessary or simplified. In addition, the integrally formed product including the mandrel, the blade and the side plate and the auxiliary mandrel not only engage the protrusion of the mandrel and the protrusion of the auxiliary mandrel, but also the protruding portion of the vane and the auxiliary mandrel surround. Since it is mounted so as to be engaged in the direction, it is possible to securely and firmly connect the auxiliary core plate to the integrally molded product, and thus, the impeller having high mechanical strength and safety can be obtained. .

Further, since the impeller of the present invention is configured such that the average diameter of the impeller is increased by the auxiliary core plate, the air volume can be increased without increasing the rotation speed as compared with the impeller without the auxiliary core plate. Since it can be increased, the noise of the impeller can be reduced, and it is also suitable for equipment that needs to be quiet, such as an air conditioner.

[Embodiment] An embodiment of the impeller of the centrifugal blower of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, this impeller includes a core plate 2 having a boss portion 1, blades 3, side plates 4, and an auxiliary core plate 6.

The mandrel 2 has a substantially truncated cone shape, and the boss portion 1 is integrally formed in the center. The boss has a hole for inserting and fixing the rotating shaft of the motor.

The side plate 4 has an opening in the center for guiding the external gas to the blades 3, and is formed substantially parallel to the rotation axis and extends in the axial direction. The suction side portion 4a is bent smoothly in the radial direction from the suction side portion 4a. A curved portion (intermediate portion) 4c extending in the discharge direction and a discharge side portion 4b.

The blades 3 form the same space around the rotation axis of the impeller, and are arranged between the side plate 4 and the core plate 2 while being inclined with respect to the radius line of the virtual circle having the rotation axis as the center. 2 and the side plate 4 are integrally formed. Then, as will be described later, the blade 3 is provided with a side plate 4 from a position integrally formed with the core plate 2.
A protruding portion that extends outward to a position approximately equal to the outer diameter of the.

As shown in FIGS. 2 to 4, the auxiliary mandrel 6 has a size such that the inner diameter thereof overlaps the outer diameter of the mandrel 2, and the outer diameter thereof is substantially equal to the outer diameters of the blades 3 and the side plates 4. As shown in FIGS. 2 and 4, the inner diameter side is in the form of a raised ring. The surface of this auxiliary mandrel is 2a
As shown in the figure, the streamline 7 of the impeller flowing on the surface of the core plate 2
And is formed so as to be continuous with the surface of the core plate 2.

This impeller is manufactured by integrally molding the core plate 2, the blades 3, and the side plate 4 with a synthetic resin, and joining the auxiliary core plate 6 separately molded with the synthetic resin to the integrally molded product. A protrusion 2a formed on the outer peripheral edge of the mandrel 2, a protruding portion of the blade 3 located on the outer diameter side of the mandrel 2, a first protrusion 6a formed on the inner diameter side of the auxiliary mandrel 6, and an outer auxiliary mandrel The second protrusion 6d formed on the radial side and the third protrusion 6b provided between the first protrusion and the second protrusion constitute a coupling means for connecting the integrally molded product and the auxiliary mandrel. There is.

The protrusion 2a projects from the outer peripheral edge of the core plate to the side opposite to the flow path, and the outside diameter of the core plate 2 including the protrusion 2a is smaller than the inside diameter of the side plate 4.

The protruding portion of the blade 3 located outside the core plate 2 is
A first portion 3 extending continuously from the lower end of the protrusion 2a of the core plate 2.
c, the second portion 3a located on the air outlet side, and the third portion connecting these portions and forming a slope along the streamline 7
Part 3b.

The first protrusion 6a of the auxiliary mandrel 6 has the form of a cylindrical wall integrally formed with the auxiliary mandrel 6, as shown in FIGS. The third protrusions 6b are also formed concentrically with the auxiliary core plate 6, but have grooves 6f formed at equal intervals in the circumferential direction. The groove 6f has a shape and a width with which the first portion 3c of the blade 3 can be fitted. First protrusion 6a
Circumferential groove 6c formed between the second protrusion 6b and the third protrusion 6b
When the auxiliary mandrel 6 is joined to the integrally molded product,
Is fitted in the groove 6c. The second protrusion 6d is
It is located on a concentric circle that shares a central axis with the auxiliary mandrel 6, is formed near the outer peripheral edge of the auxiliary mandrel 6, and is provided in a number related to the number of blades 3. The second protrusion 6d is
The second portion 3a forming the protruding portion of the blade is formed in the auxiliary mandrel 6 in a pair so as to fit therein, and the groove 6e is formed in the second portion.
Are formed between the protrusions 6d. The groove 6e has such a shape and width that the auxiliary core plate 6 can fit the second portion 3a of the protruding portion of each blade 3. Then, as shown in FIG. 9, the second protrusion 6d is formed such that the portion on the opposite side to the groove 6e side is a slope that gradually rises from the surface of the auxiliary mandrel 6 toward the top of the protrusion 6d. , It is almost in the form of a triangular prism.

As described above, in this impeller, the core plate 2, the blades 3 and the side plates 4 are integrally molded, and the auxiliary core plate 6 is separately molded. However, the core plate 2, the blades 3 and the side plates 4 are integrally molded. Is performed by an upper mold and a lower mold in which the line indicated by reference numeral 5 in FIG. 5 is a mating surface or a dividing surface. As shown in FIG. 2 or 5, the mating surface 5 is a portion (side plate) on the inner surface in the vicinity of the suction side portion 4a extending in the axial direction of the impeller or the connecting portion between the suction side portion 4a and the intermediate portion 4c. Minimum diameter portion A), a portion B on the blade that is distant from the portion A in the axial direction, and a portion C on the outer peripheral side of the core plate 2 are formed by a line formed by a line. By constructing the mating surface 5 in this way, the upper end of the blade forming portion of the lower molding die does not have a sharp sharp edge, but has an edge with a thickness in the radial direction indicated by the line AB. It is possible to significantly extend the life of the molded product, and to obtain a molded product with stable quality and high quality for a long period of time. Of the portion forming the line 5, the line connecting the minimum diameter portion A on the inner surface of the side plate 4 and the portion B on the blade is actually located slightly below the upper end surface of the blade 3. ing. That is, the vane 3 has its upstream end formed, for example, in a semicircular cross-section to reduce the collision loss of the inflowing gas to the vane and smooth the flow. Therefore, in FIG. 5, the blade 3 on the outer diameter side of the mating surface 5 is formed so that the thickness thereof gradually decreases from the upper end portion to the lower end portion in the drawing, and the draft is given to the lower molding die, and The line connecting the minimum diameter portion A of the side plate 4 and the portion B on the blade needs to be placed in the maximum thickness portion.

Molding is performed by setting an upper molding die having such a mating surface 5 and a lower molding die in an injection molding machine, injecting a synthetic resin,
After curing, it is done by pulling the lower mold downward in FIG. The auxiliary core plate 6 is molded by an injection molding machine separately from a molding die different from this molding die.

Assembling the integrally formed product including the core plate 2, the blades 3 and the side plates 4 and the auxiliary core plate 6 formed as described above forms the integrated body with the first protrusion 6a of the auxiliary core plate 6. The first portion 3c of the protruding portion of the blade 3 is engaged with the outer peripheral projection 2a, and is inserted into the groove 6f formed between the third projection 6b.
Is further fitted, and the second portion 3a of the protruding portion of the blade 3 is fitted into the groove 6e between the second protrusions 6d, and ultrasonic bonding or solvent bonding is performed.

That is, as shown in FIGS. 6 and 7, the connection between the core plate 2 and the auxiliary core plate 6 is such that the protrusion 2a is fitted into the groove 6c, and the connection between the blades 3 and the auxiliary core plate 6 is as follows. The first portion 3c of the protruding portion of the blade 3 is fitted in the groove 6f, and the second portion 3a of the protruding portion of the blade 3 is fitted in the groove 6e as shown in FIGS. It is performed by bonding by sonic bonding or solvent bonding. In the case of ultrasonic bonding, as described in, for example, Japanese Patent Laid-Open Nos. 50-45445 and 50-45310, the first and second protrusions 2a of the core plate 2 and the protruding portion of the blade 3 are formed. A portion that is melted by ultrasonic waves is formed at the lower edge of each of the second portions 3c and 3a. The first portion 3c of the protruding portion of the blade 3 and the protrusion 6 of the auxiliary mandrel 6
a slight gap formed with b and the second portion 3
The slight gap 61 formed between a and the second protrusion 6d is used for the ultrasonic bonding, and the protrusion 2a of the core plate and the blade 3 are formed.
It is filled by melting the above-mentioned protrusions provided in the.

According to this embodiment, since it is configured as described above,
When the auxiliary core plate 6 is assembled to the integrally formed product including the core plate 2, the blades 3 and the side plates 4, for example, by ultrasonic bonding, first, the integrally formed product including the core plate 2, the blades 3 and the side plates 4 is ultrasonically bonded. The auxiliary mandrel 6 is placed on the vibrator of the joining device, the auxiliary mandrel 6 is placed on the integrally molded product, and the projections 2a of the mandrel 2 are fitted into the grooves 6c of the auxiliary mandrel 6 so that the protrusions of the auxiliary mandrel 6 6a
Contacts the inner peripheral surface of the protrusion 2a of the core plate 2 forming an integrally molded product, and the centers of the core plate 2 and the auxiliary core plate 6 are aligned. After that, when the auxiliary mandrel 6 is slightly rotated, each of the first portions 3c of the protruding portions of the blade 3 is fitted into each of the grooves 6f of the auxiliary mandrel 6, and at the same time, the protrusion of each blade 3 is protruded. The second portion 3a of the portion extends along the slope of the projection 6d and then falls into each groove 6e, so that the relative positional relationship between the integrally molded product and the auxiliary core plate 6 can be easily and accurately positioned. . When the auxiliary mandrel 6 is rotated, the protrusions 6a and 6b of the auxiliary mandrel 6 rotate while sandwiching the protrusion 2a of the mandrel 2, so that the auxiliary mandrel 6 does not eccentrically rotate. After positioning in this way, ultrasonic bonding is performed to bond the auxiliary core plate 6 to the integrally molded product, and the assembly of the impeller is completed.

In the assembled impeller, the integrally molded product consisting of the core plate 2, the blades 3, and the side plates 4 and the auxiliary core plate 6 are injection molded, and each has a high precision, so a dynamic balance (dynamic balance) according to the design is assembled. At the same time, it can be secured, and the balance adjustment after assembly is unnecessary or can be simplified. Therefore, an impeller of a centrifugal blower having uniform size and mechanical strength can be obtained. Then, even if the assembled impeller is incorporated into an air conditioner and the like, and then the joint portion between the integrally molded product and the auxiliary mandrel 6 changes with time, the centrifugal force applied to the auxiliary mandrel 6 when rotated is The force that is received by the engagement between the protrusion 2a of the mandrel 2 and the protrusion 6a of the auxiliary mandrel 6 and that tries to bend the blade 3 based on the wind pressure is the connecting portion of the mandrel 2 with the blade 3 and the auxiliary mandrel. Since it is received by the projections 6b and 6d of 6, the load on the joint is reduced, and the impeller having high mechanical strength and safety as a whole can be obtained.

Furthermore, since the auxiliary impeller 6 increases the average diameter of the impeller that affects the fluid performance of the assembled impeller, a large air volume is obtained. Therefore, as compared with an impeller without an auxiliary mandrel, the rotation speed of the impeller can be reduced by the amount of increase in the air flow due to the auxiliary mandrel, and as a result, the impeller noise can be reduced, so that a quiet air conditioner can be provided. Obtainable. This will be described in more detail.

The flow coefficient φ, the pressure coefficient φ, and the noise SPL (dB) that determine the fan characteristics are Q (m 3 / min) for the air volume, D (m) for the outer diameter of the impeller, P (mmAq) for the pressure, and N
(Rpm), gravitational acceleration is g (m / sec 2), specific weight is γ (kg / m 3), and fan specific noise is K.

From these equations, when the flow coefficient φ at the point of use, which is determined by the fan characteristics and the load, is the same, the larger the outer diameter D of the impeller, the lower the rotational speed N can be, and the smaller the specific noise becomes. In the impeller whose outer diameter of the core plate is smaller than the inner diameter of the side plate as described in JP-B-52-49569, the intermediate value between the outer diameter of the side plate and the outer diameter of the core plate is treated as almost the outer diameter of the impeller. However, in the impeller according to the present invention, the average outer diameter of the impeller becomes the outer diameter of the auxiliary mandrel 6, and as a result, the air volume can be increased, so that the rotational speed can be reduced by that amount and noise can be reduced. In the case of the impeller without the auxiliary mandrel 6 in the state shown in FIG. 5, the air volume can be increased by increasing the average outer diameter of the impeller, but not only the impeller becomes large but also the core. Since a large eddy current is generated in the outer peripheral portion of the plate, efficiency is reduced and specific noise is increased. On the other hand, in the impeller according to the present invention provided with the auxiliary core plate 6, as described above, the surface of the auxiliary core plate 6 is in the form along the streamline 7 of the fluid flowing along the core plate 2. Since it functions to guide the fluid, no eddy current is generated on the outer peripheral side of the core plate 2, and therefore noise can be greatly reduced.

FIGS. 10 to 13 show another embodiment of the impeller of the centrifugal blower of the present invention, showing the construction of the blade 3 and the auxiliary mandrel 6.

On the auxiliary mandrel 6, similar to the above-described embodiment, the first protrusion 6 is formed.
a and the third protrusion 6b. But the feather 3
The groove 6f formed by the projection 6b for fitting the first portion 3c of the projection is located above the flow channel surface of the auxiliary mandrel 6 as shown in FIGS. 10 and 11. It is shallowly formed on 6b. The groove 32 into which the second portion 3a of the protruding portion of the blade 3 is fitted is made by forming a groove on the surface of the auxiliary core plate 6 as shown in FIGS. The second protrusion 6d as in the example is not provided. The groove 32 has a length that does not reach the outer peripheral edge portion of the auxiliary core plate 6, and is formed so that a part of the blade is engaged with the auxiliary core plate 6 near the outer peripheral edge portion of the auxiliary core plate 6. ing.

In this embodiment, assembling of the integrally formed product including the core plate, the blades and the side plates and the auxiliary core plate 6 is performed by firstly forming the circumferential groove 6c formed in the auxiliary core plate 6, the groove 6f between the protrusions 6b and the auxiliary core plate. The solvent is poured into the groove 32 formed on the outer periphery of the groove 6, and then the groove 6c and the protrusion 2a, the groove 6f and the first portion 3c of the protruding portion of the blade 3, and the second portion 3a of the groove 32 and the protruding portion of the blade 3a. Are fitted and joined together. This work is performed, for example, by placing an integrally molded product on a table or the like and fitting the auxiliary core plate 6 thereon from above.

In this embodiment, the groove 6f between the protrusions 6b is formed higher than the flow channel surface of the auxiliary mandrel 6 and the groove 32 is formed lower than the flow channel surface of the auxiliary mandrel 6, so that the auxiliary mandrel 6 is formed. When joining,
It is possible to prevent the solvent that has flowed into the grooves 6c and 32 from flowing out, and to perform the bonding more reliably, and to prevent the occurrence of imbalance due to the solvent flowing out and the occurrence of unevenness due to the solvent on the channel surface. There is.

Also, in this embodiment, the same effect as that of the above embodiment can be obtained. That is, the auxiliary mandrel 6 is assembled to the integrally formed product including the mandrel 2, the blades 3 and the side plates 4, after the protrusion 2a of the mandrel 2 is fitted into the groove 6c of the auxiliary mandrel 6 and then the integrally formed product or By slightly rotating the auxiliary mandrel 6 in the circumferential direction, the first part of the blade 3 at the protruding portion can be easily formed.
The portion 3c can be fitted in the groove 6f of the auxiliary mandrel 6, and the second portion 3a can be fitted in the groove 32. By fitting the protrusion 2a of the mandrel 2 into the groove 6c of the auxiliary mandrel 6, the first protrusion 6a of the auxiliary mandrel 6 is brought into contact with the inner peripheral surface of the protrusion 2a of the mandrel 2 forming the integrally molded product. Thus, the centering of the core plate 2 and the auxiliary core plate 6 is automatically performed. After that, when the integrally molded product or the auxiliary mandrel 6 is rotated, the protrusion 2a of the mandrel 2 becomes
Since it is guided by the projections 6a and 6b, it does not rotate eccentrically, and the work can be performed very easily. In the assembled impeller, the center of the integrally molded product and the center of the auxiliary core plate 6 are aligned with each other, and the integrally molded product and the auxiliary core plate 6 are injection-molded high-precision ones. Can be unnecessary or simplified. In addition, even if a defect occurs due to secular change or the like in the joint portion between the integrally molded product and the auxiliary core plate 6 after a long period of time by incorporating it into an air conditioner or the like, the protrusions 2a, 6a, 6b will have the grooves 6c, 6 respectively.
Since the integrally molded product and the auxiliary core plate 6 are firmly coupled together with f and 32, their separation can be prevented.
Further, in the assembled impeller, the average diameter of the impeller is increased by the auxiliary mandrel 6, so that the air volume can be increased, and the rotational speed of the impeller can be reduced by this increase, and the surface of the auxiliary mandrel 6 can be reduced. Since the shape follows the core plate 2, an extremely quiet impeller can be obtained.

[Effects of the Invention] As described above, since the centrifugal impeller of the present invention is provided with the impeller splashing auxiliary core plate, a sufficient air volume can be obtained without increasing the rotation speed, and thereby noise reduction is achieved. In addition, since the projections formed on the core plate and the projections that engage in the radial direction are formed on the auxiliary core plate, the auxiliary core plate can be easily formed into an integrally molded product including the core plate, the blades, and the side plates. It is possible to assemble with high precision, and it is possible to obtain an impeller with high mechanical strength, which makes it unnecessary or simple to adjust the dynamic balance after assembling. Further, in the impeller of the present invention, the integrally formed portion including the core plate, the blade, and the side plate has a minimum diameter portion A of the side plate, a portion B on the blade separated from this portion in the axial direction and a portion on the outer peripheral side of the core plate. Since it is integrally molded by two molding dies having mating surfaces related to the line connecting C, the blade has a side plate that smoothly bends in the radial direction from the suction side and extends in the discharge direction. There is also an effect that the car can be manufactured with a long-life molding die that is divided into two parts and has high durability.

[Effects of the Invention] As described above, the impeller of the centrifugal blower of the present invention is
Since it has an auxiliary mandrel, sufficient air volume can be obtained without increasing the number of revolutions, which can reduce noise, and assists the protrusions formed on the mandrel and engaging in the radial direction. Since it is formed on the mandrel, the auxiliary mandrel can be easily and highly accurately assembled into an integrally molded product consisting of the mandrel, the blades, and the side plates, making it unnecessary or simple to adjust the dynamic balance after assembling. Moreover, since the protruding portion of the blade and the auxiliary mandrel are mounted so as to engage with each other in the circumferential direction, an impeller having high mechanical strength can be obtained. Further, in the impeller of the present invention, the integrally molded product including the core plate, the blade, and the side plate is the minimum diameter portion A of the side plate, the portion B on the blade separated from this portion in the axial direction and the portion on the outer peripheral side of the core plate. Since it is integrally molded by two molding dies having mating surfaces related to the line connecting C, the impeller with good performance has a side plate that smoothly bends radially from the suction side and extends in the discharge direction. There is also an effect that it can be manufactured by a long-life molding die which is divided into two and has high durability.

[Brief description of drawings]

1 to 9 show an embodiment of an impeller of a centrifugal blower of the present invention, FIG. 1 is an overall plan view, and FIG. 2 is a sectional view of the same.
FIG. 2a is an explanatory view showing the structure of the surface of the auxiliary mandrel which constitutes the impeller of this embodiment, FIG. 3 is a plan view showing a part of the auxiliary mandrel in a cutaway view, and FIG. 4 is the same. FIG. 5 is a cross-sectional view of a plate, FIG. 5 is a cross-sectional view showing an example of an integrally molded product composed of a core plate, blades and side plates constituting the impeller of the present invention, and FIG. 6 is a core plate of an impeller and an auxiliary core plate. FIG. 7 is an enlarged cross-sectional view of the coupling portion, FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6, and FIG. 8 is an enlarged cross-sectional view of a joint portion between the blade of the impeller and the outer peripheral portion of the auxiliary mandrel. FIG. 9 is a view taken along the line IX-IX in FIG. 10 to 13 show another embodiment of the impeller of the centrifugal blower of the present invention.
7 is a view showing a portion corresponding to FIG. 7, FIG. 11 is a sectional view taken along line XI-XI of FIG. 10, FIG. 12 is a view showing a portion corresponding to FIG. 8, and FIG. Is XII in Figure 12
It is a sectional view taken along the line I-XIII. 1 ... Boss part, 2 ... Mandrel, 2a ... Mandrel protrusion, 3 ...
... Blade 3a, 3b, 3c ... Protruding portion of blade outside the core plate, 4 ... Side plate, 4a ... Suction side portion, 4
b ... Discharge side part, 4c ... Curved part (intermediate part), 5 ...
Mating surface, 6 ... Auxiliary mandrel, 6a ... First protrusion, 6b
...... Third protrusion, 6d ... Second protrusion, 32 ... Auxiliary core plate groove, A ... Side plate minimum diameter portion, B ... Portion on blade, axially separated from portion A, C: The outer peripheral side of the core plate.

Front page continued (72) Inventor Yuji Tsujita 390 Muramatsu Shimizu City, Shizuoka Prefecture, Hitachi Shimizu Plant (72) Inventor Hironori Eto 390 Muramatsu Shimizu City, Shizuoka Hitachi Ltd. Shimizu Plant (72) Inventor Katsuaki Kikuchi 390 Muramatsu, Shimizu, Shizuoka Prefecture, Hitachi, Ltd., Mechanical Research Laboratory (72) Inventor, Masato Itagaki 390, Muramatsu, Shimizu, Shizuoka, Hitachi, Ltd., Mechanical Research Laboratory, Ltd. (56) Reference JP-A-50-45445 (JP, A) JP-A-53-134209 (JP, A) JP-A-53-134208 (JP, A) Actually developed 57-89897 (JP, U) JP-B-52-49569 (JP, B2)

Claims (1)

[Claims] 1. A core plate integrally formed with a boss portion coupled to a rotary shaft, extending in the outer diameter direction, and having a projection protruding toward the side opposite to the flow passage on the outer peripheral edge portion thereof, and the core plate and the side plate described later are integrated. A blade having a protruding portion that is formed on one circle and that extends outward from a position integrally formed with the core plate to a position that is approximately equal to the outer diameter of the side plate, A suction side portion integrally formed with the vane on the side opposite to the core plate and having an inner diameter larger than the outer diameter of the core plate, and extending in the axial direction, and smoothly curved in the radial direction from the suction side portion and in the discharge direction. A side plate with a curved portion extending to
The outer peripheral edge portion of the core plate has a protrusion that is arranged on the inner peripheral side of the protrusion and that engages with the protrusion in the radial direction, and is attached so as to engage with the protruding portion of the blade in the circumferential direction. And an auxiliary mandrel configured to have substantially the same outer diameter,
The core plate, the blades, and the side plates are associated with a line connecting the minimum diameter portion A of the side plate, the portion B on the blades axially distant from the minimum diameter portion A, and the portion C on the outer peripheral side of the core plate. An impeller of a centrifugal blower, which is integrally molded by two molds having a surface.