JPH0596494U - Metal axial fan - Google Patents

Abstract

(57) [Abstract] [Purpose] The stress applied to the fixed portion on the fan blade side formed by the protruding wall of the spider is reduced, and there is no fear of cracks or slack in the fixed portion, and the fixed state is secured for a long time. Try to maintain. An axial flow fan in which fan blades are radially fixed outward by rivets to the protruding wall portions of a spider having a plurality of protruding walls on the circumferential side, and the respective fixing portions are provided. Is surrounded by a substantially U shape, and a concave or convex bead wall is provided on the surface on the fan blade side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention generally relates to the improvement of the structure of a metal axial fan, which is used for cooling an engine of an automobile, and which is driven at a relatively high speed and constantly repeated low and high speeds.

[0002]

[Prior Art]

 Conventionally, as an axial fan of this type, for example, as shown in FIG. 4, a protruding wall (11 ') of a spider (11) has a different thermal expansion coefficient from that of the spider (11), such as a steel plate or aluminum. Each of the metal fan blades (12) made of an alloy plate or the like is simply fixed to the rivet (13) with a flat surface state.

[0003]

[Problems to be solved by the device]

 However, in such a conventional technique, fatigue stress is caused by a difference in thermal expansion due to heat from the engine portion, centrifugal force at high speed rotation, wind pressure and continuously repeated low speed, high speed rotation driving state or vibration. And the tip side of the fan blade tends to vibrate (the natural frequency is low), and this vibration is transmitted and tends to cause cracks or looseness on the fan blade (12) side near the fixed part due to rivets. However, the current situation is that security measures are desired.

The present invention has been made in view of the above problems of the prior art. In the drive state of the engine side, the function of the bead wall that surrounds the fixing portion in a substantially U-shape makes the fan blade side of the fan blade side. It is possible to provide a metal axial fan that can reduce the stress applied to each fixed part and increase the natural frequency to eliminate the fear of cracks and slack at the fixed part for a long period of time. It is intended.

[0005]

[Means for Solving the Problems]

 According to the present invention, in order to achieve the above object, fan blades are radially fixed by rivets to the protruding wall portions of a spider having a plurality of protruding walls on the circumferential side. In the axial flow fan, the metal axial flow fan is configured by enclosing each of the fixed portions in a substantially U shape and providing a concave or convex bead wall on the surface on the fan blade side. In addition, a bead wall extending inward from the bead wall is further provided so as to surround the fixed portion, and a bead wall extending outward from the bead wall is further provided.

[0006]

[Action]

 Since the present invention is constructed in this way, the reinforcing function of the bead wall enhances the rigidity, and centrifugal force, wind pressure, and continuously low-speed and high-speed rotational drive conditions or heat and heat which are repeatedly applied to the engine are increased. The stress applied to the fixed part on the fan blade side due to vibration etc. is effectively reduced, and the natural frequency is increased to reduce the amplitude, eliminating the fear of cracking or loosening at the fixed part for a long time. It is possible to reliably maintain the fixed state throughout.

[0007]

【Example】

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway front view of a metal axial fan of the present invention, and FIG. 2 is a view corresponding to FIG. FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG. 1A, in which (1) is a spider having a plurality of protruding walls (1 ′) on its peripheral side portion. Each of (2) is a fan blade, which is fixed to the protruding wall (1 ') of the spider (1) by a rivet (3) and radially attached to the outside. On the other hand, on the surface of the fan blade (2), the fixed part by the rivet (3) and the protruding wall (1 ') of the spider (1) are surrounded by a substantially U-shape that is open to the root side. A bead wall (4) of concave or convex shape is provided. Providing a bead wall (4a) that extends inside the substantially U-shaped bead wall (4) and surrounds at least the fixed portion on the tip side of the fan blade (2) that easily vibrates is particularly effective for vibration isolation. There is. Further, by providing a bead wall (4b) extending outside the substantially U-shaped bead wall (4), particularly toward the tip corner of the fan blade (2), the effect of increasing rigidity (natural frequency) is further exerted. Be done.

[0008]

[Effect of the device]

 As described above, the metal axial fan according to the present invention has the bead wall (4) on the surface surrounding the respective fixed portions formed by the protruding wall (1 ') of the spider (1). Since the fan blades (2) are used, they are in the drive state on the engine side due to the reinforcing function at the bead wall, the rigidity improvement accompanying it, and the increase in natural frequency. The stress applied to the fixed portion of the fan blade can be absorbed and effectively reduced, and the fixed state can be reliably maintained for a long period of time without the fear of cracks or slack in the fixed portion on the fan blade side. It is a useful metal axial fan.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a metal axial fan according to an embodiment of the present invention.

FIG. 2 is a view corresponding to FIG. 1 of the same as another embodiment.

FIG. 3 is a cross-sectional view taken along line AA of FIG.

FIG. 4 is a transverse cross-sectional view of a fixing portion by enlarging a metal axial fan according to a conventional example.

[Explanation of symbols]

 2 Fan blades 4, 4a, 4b Bead wall

Claims (3)

[Scope of utility model registration request] 1. An axial fan in which fan blades are radially fixed outward by rivets to the protruding wall portions of a spider having a plurality of protruding walls on the circumferential side thereof. An axial fan made of metal, characterized in that the fixed portion is enclosed in a substantially U shape and a concave or convex bead wall (4) is provided on the surface of the fan blade (2) side. 2. A bead wall (4) surrounding the fixed part.
The metal axial fan according to claim 1, further comprising a bead wall (4a) extending inwardly from the inner wall. 3. A bead wall (4) outward from the bead wall (4).
The axial fan made of metal according to claim 1, characterized in that b) is further extended.