centrifugal blower

Abstract

To provide a centrifugal blower which achieves improvement of workability when a connection terminal for grounding connected to a circuit board disposed in a motor is grounded on a case of the motor.SOLUTION: In a centrifugal blower, an impeller, a motor for rotating the impeller, and a circuit board 144 having a GND pattern formed are housed at the inner side of a lower casing 112. The motor is disposed at one end part side as seen in an axial direction of the circuit board 144. The motor includes a conductive housing 131 including an opening which is open at the other end part side as seen in the axial direction. An annular end cap 160 is disposed at the other end part side as seen in the axial direction of the circuit board 144. A pin part 222 of one end part of a connection terminal 200 is connected to the GND pattern. The other end part of the connection terminal 200 is provided with a contact piece 233 which has a spring property and elastically contacts with an inner peripheral surface of the housing 131.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a centrifugal fan in which a ground connection terminal connected to a circuit board of a motor can be easily grounded to a case of the motor. [Background technology]

[0002] Conventionally, centrifugal fans have been widely used for blowing air, cooling, etc. in home appliances, office equipment, in-vehicle batteries, and industrial and vehicle air conditioners (see, for example, Patent Document 1). As shown in Fig. 11, the centrifugal fan disclosed in Patent Document 1 includes a casing 10, inside which are housed an impeller 20 with a plurality of blades 21 and a motor 30 that rotates the impeller 20.

[0003] Here, the motor 30 is equipped with a circuit board on which a control circuit and electronic components for driving and controlling the motor 30 are mounted, and a GND pattern formed on the circuit board is connected to a metal motor case.

[0004] Conventionally, a motor has been proposed in which a grounding wire connected to a GND pattern of a circuit board is connected to a motor case (see, for example, Patent Document 2). In the motor of Patent Document 2 shown in Fig. 12, one end of a grounding wire 103 is connected to a circuit board 5, and a connection terminal 104 provided on the other end 103b of the grounding wire 103 is fixed with a screw member 55 to a first wiring flange portion 43B formed on a first case portion 11B of the motor case. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-016152 [Patent Document 2] Japanese Patent Application Publication No. 2019-180139 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the motor of Patent Document 2 shown in FIG. 12 is applied as the motor of the centrifugal blower of Patent Document 1 shown in FIG. 11, the motor of Patent Document 2 has a structure in which a connection terminal 104 is provided at the other end 103b of the grounding wiring 103 connected to the circuit board 5, and the connection terminal 104 is fixed to the first wiring flange portion 43B formed on the motor case with a screw member 55, which requires the work of fixing with the screw member 55, and an improvement to improve workability is desired.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a centrifugal fan that improves workability by eliminating the need to use screw members to fix a grounding connection terminal connected to a circuit board arranged on a motor to the motor case. [Means for solving the problem]

[0008] The present invention provides a centrifugal blower that houses an impeller, a motor for rotating the impeller, and a circuit board on which a GND pattern is formed inside a casing, wherein the motor is disposed on one axial end side of the circuit board, and the motor comprises a stator and a housing made of a conductive material and having a cylindrical portion that houses the stator inside, and an end cap with an annular portion is disposed on the other axial end side of the circuit board, the stator is disposed on the inner peripheral surface of the housing, and the annular portion of the end cap faces the inner peripheral surface of the cylindrical portion of the housing, one end of a connection terminal is connected to the GND pattern, and the other end of the connection terminal is interposed between the annular portion of the end cap and the inner peripheral surface of the cylindrical portion of the housing and abuts against the cylindrical portion, The other end of the connection terminal is formed with a contact piece that elastically contacts the cylindrical portion of the housing. It is a centrifugal blower.

[0009] According to the present invention, one end of the connection terminal, the other end of which is connected to the GND pattern, is interposed between the annular portion of the end cap and the cylindrical portion of the housing and abuts against the cylindrical portion, so that there is no need to fix the connection terminal with a screw member when grounding it to the motor casing, thereby improving workability. [Effects of the Invention]

[0010] According to the present invention, a centrifugal fan is provided that does not require the work of fixing the connection terminal to the casing of the motor with a screw member when grounding the connection terminal to the casing of the motor, thereby improving workability. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1A is a rear view of a centrifugal fan according to an embodiment of the present invention, and FIG. 1B is an enlarged view of a portion indicated by an arrow B in FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 10 is a perspective view showing a state in which the end cap shown in FIG. 9 is attached to the lower casing. FIG. [Figure 4] FIG. 4 is a perspective view of FIG. 3 as seen from the back side. [Figure 5] FIG. 3 is an enlarged cross-sectional view of a main part of FIG. 2. [Figure 6] FIG. 2 is a perspective view showing a stator in the embodiment. [Figure 7] FIG. 7 is an enlarged cross-sectional view of a portion indicated by an arrow VII in FIG. 5. [Figure 8] FIG. 2 is a perspective view showing an end cap in the embodiment. [Figure 9] FIG. 9 is a perspective view showing a state in which a motor is attached to the end cap shown in FIG. 8. [Figure 10] 1A and 1B are a perspective view and a side view showing a connection terminal according to an embodiment of the present invention; [Figure 11] FIG. 1 is a cross-sectional view showing a conventional centrifugal blower (Patent Document 1). [Figure 12] FIG. 1 is a cross-sectional view showing a conventional brushless motor (Patent Document 2). DETAILED DESCRIPTION OF THE INVENTION

[0012] 1.Configuration of centrifugal blower A centrifugal fan 100 according to one embodiment of the present invention will be described with reference to Figures 1 to 10. As shown in Figure 2, the centrifugal fan 100 comprises an impeller 120 that has an inner space on the axial center side and a plurality of blades 121 arranged in an annular portion around the inner space, and that rotates to exhaust air from the inner space in a centrifugal direction through the plurality of blades 121, a spiral-shaped casing 110 that houses the impeller 120 inside in a rotatable state, and an intake port 114 that is an opening provided at a position facing the inner space of the impeller 120 and that introduces air into the inner space of the impeller 120.

[0013] The centrifugal blower 100 includes a casing 110. The casing 110 is composed of an upper casing 111 molded from resin and a lower casing 112 molded from resin. As shown in FIG. 3, a plurality of claws 112a are formed at equal intervals in the circumferential direction on the lower edge of the outer periphery of the lower casing 112. The claws 112a protrude axially downward and radially outward at the lower end. On the other hand, as shown in FIG. 1, a plurality of rectangular frame-shaped engaging portions 111a are formed on the outer periphery of the upper casing 111. The engaging portions 111a are inserted into and engage with the claws 112a, thereby joining the upper casing 111 and the lower casing 112.

[0014] In this embodiment, the main components are included in the lower casing 112, and therefore the upper and lower sides are shown in Fig. 2 and Fig. 3. Therefore, in the following description, terms indicating directions such as "upper" and "lower" are used to indicate the directions in Fig. 2 and Fig. 3.

[0015] A spiral flow path 113 (see FIG. 2) is formed inside the casing 110. The flow path 113 has a structure in which the cross-sectional area gradually increases as it moves clockwise from the start point where the gap between the impeller 120 and the casing 110 is smallest. An outlet 115 is formed at the end of the flow path 113. That is, the spiral flow path 113 has a structure in which the cross-sectional area gradually increases toward the outlet 115.

[0016] The upper casing 111 has a suction port 114 that opens in the axial direction. Here, the axis refers to the shaft 151 of the impeller 120, and the axial direction refers to the direction in which it extends. The lower casing 112 has fixing legs 116 for attaching and fixing to another device or housing, and is also equipped with a motor 130 (see Figure 2) for rotating the impeller 120. In Figure 1(A), reference numeral 116a denotes a metal collar.

[0017] As shown in Fig. 2, impeller 120 is fixed to shaft 151 of motor 130, and when motor 130 rotates, impeller 120 rotates. When impeller 120 rotates, air is sucked in through suction port 114 and guided inside impeller 120 (internal space on the axial center side). This air is blown out in a centrifugal direction from the inside of impeller 120 by the action of blades 121. The air blown out from impeller 120 flows through spiral flow path 113 toward discharge port 115 shown in Fig. 1 and is exhausted from discharge port 115.

[0018] The impeller 120 has a cup-shaped hub 122 that forms the top surface, a plurality of blades 121 that are arranged with the outer arc-shaped portion of the hub 122 standing upright in the axial direction, and an annular connecting ring 123 that connects the ends of the plurality of blades 121 opposite the hub 122. All of the blades 121 have the same shape, have a forward-facing blade shape that is concave with respect to the direction of rotation of the impeller 120, and are evenly arranged in the circumferential direction. An inner space is provided inside the plurality of blades 121 (towards the axial center), and when the impeller 120 rotates, air is blown out from this inner space through the blades 121 in the centrifugal direction.

[0019] 5, hub 122 has a boss 124 at its center that protrudes downward in a convex shape, and boss 124 has a through-hole 124a formed in it. A cylindrical metal (e.g., brass) bushing 125 is fixed to the inner periphery of through-hole 124a by insert molding, and a shaft 151 of motor 130 is press-fitted into bushing 125, thereby connecting impeller 120 to shaft 151. Shaft 151 is the rotating shaft of motor 130, and by being connected to impeller 120, it also serves as the rotating shaft of impeller 120. Hub 122, the plurality of blades 121, and connecting ring 123 are integrally formed from resin.

[0020] 2. Motor configuration The motor 130 is an inner rotor type three-phase brushless motor and includes a cup-shaped housing (cylindrical portion) 131 made of a conductive metal material. A stator 140 is disposed on the inner circumferential surface of the housing 131. As shown in FIG. 6, the stator 140 includes a stator core 141 formed by laminating a predetermined number of cores made of electromagnetic steel sheets, an insulator 142 attached to the stator core 141, three-phase coils 143 wound around the stator core 141 via the insulator 142, and a circuit board 144 (see FIGS. 5 and 7) disposed above the insulator 142. The stator core 141 has a plurality of teeth (salient poles) 141b extending radially inward from an annular core back portion (annular portion) 141a, and the coils 143 are wound around the teeth 141b via the insulators 142.

[0021] 7, the insulator 142 is formed with a protruding portion 142a that contacts the end face of the core back portion 141a and protrudes in the axial direction. A plurality of grooves 142b are formed in the outer peripheral surface of the protruding portion 142a and are connected in the vertical direction (axial direction), and crossover wires 143a of the coil 143 are arranged in the grooves 142b.

[0022] A rotor 150 is disposed inside the stator core 141. The rotor 150 includes a metal shaft 151, a cup-shaped rotor yoke 152 connected to the upper end of the shaft 151, and a ring-shaped rotor magnet 153 fixed to the outer peripheral surface of the rotor yoke 152. A boss portion 152a is formed in the center of the rotor yoke 152, which is made of a magnetic metal material, by, for example, burring, and the shaft 151 and the rotor yoke 152 are connected by press-fitting the shaft 151 into the boss portion 152a.

[0023] A boss portion 131a is formed in the center of the housing 131, and a metal (e.g., brass) bearing holder 132 is press-fitted into the boss portion 131a. A pair of ball bearings 133 are attached to the bearing holder 132, and the shaft 151 is rotatably supported by the pair of ball bearings 133. A compression coil spring 134 is interposed between the pair of ball bearings 133, and applies a preload to the ball bearings 133 by biasing the outer rings of the ball bearings 133.

[0024] 5, a plurality of flange portions 131b extending radially outward are formed at equal intervals in the circumferential direction around the periphery of the opening of the housing 131. A long through-hole 131c is formed in each flange portion 131b along the circumferential direction. As will be described later, this through-hole 131c is used to connect the housing 131 and the lower casing 112.

[0025] 5, a circuit board 144 having a circuit mounted thereon for driving and controlling the motor 130 is disposed axially above the stator core 141. Terminals 143c (see FIG. 6) of the coil 143 wound around the stator core 141 are inserted into through-holes (not shown) connected to wiring patterns formed on the mounting surface of the circuit board 144 and connected by solder 145 (see FIG. 3).

[0026] 3 is the mounting surface of circuit board 144. The other terminals 143c of coil 143 are bundled, twisted, and connected with solder to form common line coupling portion 143b (see FIG. 6), and common line coupling portion 143b is bent so as to be parallel to the axial direction.

[0027] 3. End cap configuration A resin end cap 160 is attached to the axially upper side of the housing 131. Fig. 8 is a diagram showing the end cap 160, and Fig. 9 is a diagram showing the state in which the motor 130 is attached to the end cap 160. The end cap 160 includes an outer annular portion 161 and an inner annular portion (annular portion) 162 arranged inside the outer annular portion (annular portion) 161 with a gap 161a therebetween. A pocket portion 163 that protrudes radially inward is formed on the inner circumferential surface of the inner annular portion 162.

[0028] Pocket portion 163 is a cylindrical member having a cross section that is approximately semicircular and open at both ends. A substantially semicircular notch (not shown) that matches the shape of pocket portion 163 is formed on the outer periphery of circuit board 144, and the lower end of pocket portion 163 is housed in the notch. Common coupling portion 143b of coil 143 of each phase protrudes axially from the notch of circuit board 144 and is inserted into pocket portion 163.

[0029] As shown in Fig. 8, a plurality of (four in this example) flanges 164 protruding radially outward are formed at equal intervals in the circumferential direction on the outer peripheral surface of the outer annular portion 161 of the end cap 160, and long through-holes 164a are formed in the flanges 164 along the circumferential direction. In addition, a plurality of (two in this example) frames 165 protruding radially outward are formed on the outer peripheral surface of the outer annular portion 161 of the end cap 160. The frames 165 are rectangular in plan view and penetrate in the axial direction. The frames 165 are used as anti-rotation devices for the cover 170, which will be described later, as needed.

[0030] A connector housing 166 is formed integrally with the end cap 160. A connector pin 167 is formed integrally with the connector housing 166 by insert molding. The connector pin 167 has a shape in which a horizontally crank-shaped wire is bent further downward (toward the circuit board 144) at its radially inner end, and one end of the connector pin 167 is passed through a through-hole (not shown) formed in the circuit board 144 and soldered to the opposite mounting surface (the back surface of the circuit board 144 in FIG. 8). The other end of the connector pin 167 protrudes into the internal space of the connector housing 166 and is connected to a socket inserted into the connector housing 166.

[0031] 8, the inner annular portion 162 of the end cap 160 is formed with a plurality of (three in this example) generally triangular protrusions 168 that protrude radially inward. A fixing pin (not shown) that protrudes downward is formed at the tip of the protrusion 168. Meanwhile, the circuit board 144 is formed with a through-hole (not shown) through which the fixing pin is inserted, and the circuit board 144 is fixed to the end cap 160 by heat caulking the fixing pin.

[0032] As shown in Fig. 8, the end cap 160 is formed with a plurality of (two in this example) protrusions 169 that protrude radially inward at the position of the flange portion 164. A connection terminal 200 is attached to the protrusions 169. The connection terminal 200 is made of a material having spring properties, and has a rectangular top plate portion 210 as shown in Fig. 10. Examples of materials that have spring properties and excellent conductivity include phosphor bronze and stainless steel for springs.

[0033] A first side plate 220 extends from one edge of the top plate 210, perpendicular to the top plate 210. A rectangular opening (engagement portion) 221 is formed in the middle of the first side plate 220 in the longitudinal direction. The tip of the opening 221 of the first side plate 220 is tapered into a triangular shape, and at the tip of that is formed an angular pin portion 222 that is inserted into a through-hole 144a (see FIG. 7) formed in the circuit board 144.

[0034] A second side plate portion 230 extends from the other edge of top plate portion 210 of connection terminal 200, perpendicular to top plate portion 210. Second side plate portion 230 has a bent portion 231 in the middle of its longitudinal direction, and bent portion 231 gives second side plate portion 230 a crank shape. A roughly U-shaped notch 232 is formed at the tip of bent portion 231, and a contact piece 233 bent toward the outside of connection terminal 200 is formed inside notch 232.

[0035] 7, an engaging portion 169a that protrudes radially inward is formed on the radially inner end face of the protrusion 169, and an inclined surface 169b is formed adjacent to the engaging portion 169a. The connection terminal 200 is mounted across the inner annular portion 162 and the protrusion 169 so that the top plate portion 210 abuts against them, and the engaging portion 169a fits into the opening 221 of the connection terminal 200, thereby fixing the connection terminal 200 to the end cap 160.

[0036] In this state, the bent portion 231 of the connection terminal 200 is placed on the bottom 162a of the gap 161a (see FIG. 8) between the outer annular portion 161 and the inner annular portion 162 of the end cap 160. A slit 164b is formed in the bottom 162a of the gap 161a, and the second side plate portion 230 of the connection terminal 200 is inserted between the outer peripheral surface of the inner annular portion 162 and the inner peripheral surface of the housing 131 through the slit 164b, with the contact piece 233 elastically contacting the inner peripheral surface of the housing 131.

[0037] 7, the pin portion 222 of the connection terminal 200 is passed through a through hole 144a formed in the circuit board 144 and is joined with solder 144b on the opposite mounting surface. The through hole 144a is connected to a GND pattern (solid pattern) formed on the circuit board 144. The inner annular portion 162 of the end cap 160 is disposed on the outer periphery of the jumper wire 143a of the coil 143, and the housing 131 is disposed on the outer periphery of the inner annular portion 162. In this way, the inner annular portion 162 prevents the jumper wire 143a and the housing 131 from coming into contact with each other and causing a short circuit.

[0038] Here, the attachment structure of the end cap 160 will be described with reference to Figure 7. As shown in Figure 7, a boss portion 112b that protrudes upward in the figure is formed near the opening of the lower casing 112. Boss portion 112b protrudes upward while passing through through-hole 131c formed in flange portion 131b of housing 131 and through-hole 164a formed in flange portion 164 of end cap 160, and its upper end is thermally caulked to form head portion 112c that presses against flange portion 164. With this configuration, the end cap 160 is joined to the lower casing 112.

[0039] A resin cover 170 is attached to the end cap 160 to prevent dust, foreign matter, and the like from entering the inside of the motor 130. The cover 170 is substantially cup-shaped, and its peripheral edge 171 extends in the axial direction. The end of the peripheral edge 171 forms a tapered portion 171a whose thickness gradually decreases toward the bottom. The cover 170 is detachably attached to the end cap 160 by pushing the tapered portion 171a into the gap 161a (see FIG. 8 ) between the second side plate portion 230 and the outer annular portion 161 of the connection terminal 200.

[0040] 4. Centrifugal blower assembly method i) Attaching to the convex part of the connection terminal 7, when the lower half of the second side plate portion 230 of the connection terminal 200 is inserted into the slit 164b between the outer annular portion 161 and the inner annular portion 162 and the connection terminal 200 is pushed in so as to cover the inner annular portion 162 and the protrusion 169, the pin portion 222 of the connection terminal 200 rides up onto the inclined surface 169b adjacent to the engagement portion 169a, then the triangular portion of the first side plate portion 220 rides up, and finally the engagement portion 169a fits into the opening 221 of the connection terminal 200, thereby fixing the connection terminal 200 to the end cap 160. As a result, the connection terminal 200 straddles the inner annular portion 162 and the protrusion 169, and the bent portion 231 of the connection terminal 200 rests on the bottom portion 162a of the inner annular portion 162.

[0041] ii) Bonding of circuit board and end cap The circuit board 144 is inserted into the end cap 160 from below, and the fixing pins of the protrusions 168 are inserted into the through holes of the circuit board 144 and then caulked and fixed on the non-mounting surface (see FIG. 8). This joins the end cap 160 and the circuit board 144. Simultaneously with this insertion operation, the angular lower ends of the multiple connector pins 167 are inserted into the through holes from the mounting surface side of the circuit board 144, and as shown in FIG. 7, the angular pin portion 222 of the connection terminal 200 is inserted into the through hole 144a formed in the circuit board 144 and connected to the GND pattern. Then, the tips of the connector pins 167 protruding from the non-mounting surface of the circuit board 144 are connected with solder, and the pin portion 222 of the connection terminal 200 protruding from the non-mounting surface of the circuit board 144 is connected with solder 144b.

[0042] iii) Connection between the motor and the end cap The terminals 143c of the coils 143 wound around the stator 140 of the motor 130 are bundled and twisted together to form the common line coupling portion 143b. The terminals 143c of the coils 143 that make up this common line coupling portion 143b are soldered together and cut to a predetermined length. This soldered common line coupling portion 143b is bent so as to be parallel to the axial direction and made upright (see FIG. 6). The terminals 143c of the coils 143 of each phase are also bent so as to be parallel to the axial direction and made upright.

[0043] Each terminal 143c of the coil 143 is inserted into a predetermined through-hole from the opposite mounting surface of the circuit board 144, and the common line coupling portion 143b is made to protrude toward the mounting surface from a notch formed in the outer periphery of the circuit board 144 and is housed in a pocket portion 163 formed in the inner periphery of the end cap 160. The above operation is performed by bringing the end cap 160, to which the circuit board 144 is coupled, and the housing 131 of the motor 130 close to each other. Then, the tips of each terminal 143c of the coil 143 protruding toward the mounting surface are connected with solder 145 (see FIG. 3).

[0044] By the above operation, contact piece 233 of connection terminal 200 comes into contact with the inner peripheral surface of housing 131. As shown by the two-dot chain line in Fig. 7, contact piece 233 of connection terminal 200 protrudes radially outward in an unloaded state, but by pressing contact piece 233 into the gap between inner annular portion 162 of end cap 160 and housing 131, contact piece 233 is pressed radially inward by housing 131 and elastically abuts against the inner peripheral surface of housing 131. As a result, the GND pattern of circuit board 144 is set to the reference potential (for example, zero volts).

[0045] iv) Connection between motor and lower casing The motor 130, to which the end cap 160 and the circuit board 144 are coupled, is inserted from above into the upper opening of the lower casing 112. At this time, as shown in FIG. 7, boss portions 112b formed around the opening of the lower casing 112 are inserted into through-holes 131c formed in flange portions 131b of the housing 131 and through-holes 164a formed in flange portions 164 of the end cap 160.

[0046] Then, the tip of boss portion 112b protruding from through-hole 164a of flange portion 164 of end cap 160 is heated and expanded to cause plastic deformation, thereby forming head portion 112c. By forming head portion 112c, end cap 160 is joined to lower casing 112.

[0047] v) Impeller to motor coupling The impeller 120 is inserted into the opening on the lower side of the lower casing 112 , and the lower end of the shaft 151 is press-fitted into the bushing 125 of the impeller 120 .

[0048] vi) Other The tapered portion 171a of the peripheral edge 171 of the cover 170 is press-fitted into the gap 161a between the outer annular portion 161 and the inner annular portion 162 of the end cap 160, and the cover 170 is attached to the end cap 160. At this time, the claw portions 112a of the lower casing 112 are inserted into and engaged with the engaging portions 111a of the upper casing 111, thereby joining the upper casing 111 and the lower casing 112. Note that a convex portion that protrudes radially outward can be formed on the outer circumferential surface of the cover 170, and the convex portion can be inserted into the frame 165 of the end cap 160 to prevent the cover 170 from rotating.

[0049] 5.Effects According to the centrifugal blower 100 having the above-described configuration, the contact piece 233 of the connection terminal 200, one end of which is connected to the GND pattern, is interposed between the inner annular portion 162 of the end cap 260 and the inner peripheral surface of the housing 131 and abuts against the inner peripheral surface of the housing 131. Therefore, when grounding the connection terminal 200 to the housing 131 of the motor 130, there is no need to fix it with a screw member, thereby improving workability.

[0050] In particular, in the above embodiment, the connection terminal 200 is attached to the protrusion 169 of the end cap 160, so that when the end cap 160 is attached to the housing 131, the connection terminal 200 is automatically grounded, thereby further improving workability.

[0051] Furthermore, in the above embodiment, the connection terminal 200 is attached to the end cap 160 so as to straddle the inner annular portion 162 and the protrusion 169, one end of the connection terminal 200 is provided with a pin portion 222 that is connected to the GND pattern, and the other end of the connection terminal 200 is formed with a contact piece 233 having spring properties on the inner surface of the housing 131, so that processing is easier than insert molding the connection terminal 200 into the end cap 160.

[0052] Furthermore, in the above embodiment, the jumper wire 143a of the coil 143 is arranged on the outer peripheral surface of the protrusion 142a of the insulator 142, and the inner annular portion 162 of the end cap 160 is arranged between the contact piece 233 of the connection terminal 200 and the jumper wire 143a, thereby preventing a short circuit between the jumper wire 143a and the contact piece 233.

[0053] Furthermore, in the above embodiment, the boss portion 112b of the lower casing 112 is inserted into the through-hole 164a of the flange portion 164 of the end cap 160, and the tip of the boss portion 112b is plastically deformed to join them, so that the end cap 160 can be easily joined to the lower casing 112. In addition, the flange portion 131b of the housing 131 has a through-hole 131c, and the boss portion 112b is inserted into this through-hole 131c, so that the housing 131 can also be easily joined to the lower casing 112.

[0054] 6. Example of changes The present invention is not limited to the above-described embodiment, but various modifications are possible as follows. i) A boss portion protruding downward is formed on the flange portion 164 of the end cap 160, and the boss portion is inserted into a through hole 131c formed in the flange portion 131b of the housing 131 of the motor 130. The tip of the boss portion protruding from the through hole 131c is heated to cause plastic deformation and thereby crimp and fix the boss portion.

[0055] ii) The flange portion 131b of the housing 131 can be press-fitted onto the inner peripheral surface of the end cap 160.

[0056] iii) The connection terminal 200 can be molded integrally with the end cap 160. For example, the connection terminal 200 can be used as an insert material by injection molding the end cap 160 so that the contact piece 233 and the pin portion 222 protrude from the end cap 160.

[0057] iv) The housing 131 is not limited to being made of metal, but may also be made of, for example, conductive resin. [Industrial Applicability]

[0058] The present invention relates to a method for supplying air, ventilating, cooling, etc. in air conditioning systems for home appliances, office automation equipment, industrial use, and vehicles. It can be used for centrifugal blowers used in [Explanation of symbols]

[0059] 100... centrifugal blower, 110... casing, 111... upper casing, 111a... engagement portion, 112... lower casing, 112a... claw portion, 112b... boss portion, 112c... head portion, 113... flow path, 114... suction port, 115... discharge port, 116... fixed leg, 116a... collar, 120... impeller, 121... blade, 122... hub, 123... connecting ring, 124... boss portion, 124a... through hole, 125... bush, 130... motor, 1 31...housing (cylindrical portion), 131a...boss portion, 131b...flange portion, 131c...through hole, 132...bearing holder, 133...ball bearing, 134...compression coil spring, 140...stator, 141...stator core, 141a...core back portion (annular portion), 141b...teeth (salient pole), 142...insulator, 142a...protrusion, 142b...groove, 143...coil, 143a...crossover wire, 143b...common wire Coupling portion, 143c...terminal, 144...circuit board, 144a...through hole, 144b...solder, 145...solder, 150...rotor, 151...shaft, 152...rotor yoke, 152a...boss portion, 153...rotor magnet, 151...shaft, 160...end cap, 161...outer annular portion, 161a...gap, 162...inner annular portion (annular portion), 162a...bottom, 163...pocket portion, 164...flange portion, 164a...through Hole, 164b...slit, 165...frame, 166...connector housing, 167...connector pin, 168...protrusion, 169...convex portion, 169a...engagement portion, 169b...inclined surface, 170...cover, 171...periphery, 171a...tapered portion, 200...connection terminal, 210...top plate portion, 220...first side plate portion, 221...opening (engagement portion), 222...pin portion, 230...second side plate portion, 231...bent portion, 232...notch, 233...contact piece.

Claims

1. A centrifugal fan having a casing that houses an impeller, a motor for rotating the impeller, and a circuit board on which a GND pattern is formed, The motor is disposed on one axial end side of the circuit board, the motor includes a stator and a housing made of a conductive material and having a cylindrical portion for accommodating the stator therein; an end cap having an annular portion is disposed on the other axial end side of the circuit board; the stator is disposed on an inner circumferential surface of the housing, the annular portion of the end cap faces an inner circumferential surface of the cylindrical portion of the housing; one end of a connection terminal is connected to the GND pattern, and the other end of the connection terminal is interposed between the annular portion of the end cap and an inner circumferential surface of the cylindrical portion of the housing and abutted against the cylindrical portion; a contact piece that elastically contacts the cylindrical portion of the housing is formed on the other end of the connection terminal;

2. The centrifugal blower according to claim 1 , wherein the connection terminal is attached across the annular portion of the end cap, and the one end of the connection terminal has a pin portion that is connected to the GND pattern.

3. The centrifugal blower according to claim 2, wherein the one end of the connection terminal is provided with an engaging portion that engages with the end cap.

4. 4. The centrifugal blower according to claim 1, wherein the motor includes a stator and a coil wound around the stator via an insulator, the stator includes an annular portion and a plurality of salient poles protruding radially inward from the annular portion, the insulator includes a protruding portion that contacts an end face of the annular portion of the stator, a jumper wire of the coil is disposed on an outer peripheral surface of the protruding portion, and the annular portion of the end cap is disposed between the other end of the connection terminal and the jumper wire of the coil.

5. The casing includes an upper casing and a lower casing, the lower casing has an opening for accommodating the motor, and includes a plurality of bosses extending around the opening toward the other end in the axial direction; The end cap includes a plurality of flange portions extending radially outward from the annular portion, the flange portions including through holes, 5. The centrifugal blower according to claim 1, wherein the boss portion of the lower casing is inserted into the through hole of the flange portion of the end cap, and the tip of the boss portion is plastically deformed to connect the lower casing and the end cap.

6. 6. The centrifugal blower according to claim 5, wherein the housing includes a plurality of flanges extending radially outward from the cylindrical portion, the flanges including through holes through which the bosses are inserted.

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