JP2013152034A - Heat exchanger and method for making the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance positional accuracy of a heat exchanging pipe to thereby enhance efficiency of heat exchange, while adopting a system casting the heat exchanging pipe in a thermoconductive body.SOLUTION: A cooling pipe 8 through which a cooling medium is passed is helically wound and fixed around an outer peripheral surface of a cylindrical base 7 and a motor housing H of a motor is constituted by casting and shaping a housing body 4 in an outer peripheral side of the base 7 with the cooling pipe 8 buried. Gaps between the pipe 8 and the base outer peripheral surface are filled with a casting material by arranging a plurality of recessed grooves 9 in the base outer peripheral surface while crossing the cooling pipe 8.

Description

  The present invention relates to a heat exchanger used as a motor housing or the like of an electric motor, and a manufacturing method thereof.

  The background art will be described taking a motor housing of an electric motor as an example.

  An electric motor includes a rotor that rotates about an electric motor shaft, a stator disposed on an outer periphery of the rotor, a cylindrical motor housing on which the stator is attached on the inner peripheral side, and a cover that closes an opening of the motor housing. Consists of.

  Since this electric motor generates heat during operation due to iron loss of the stator core and copper loss of the stator coil, the stator heat is discharged to the outside through the motor housing.

  In this case, in order to increase the heat exchange efficiency (cooling efficiency), as shown in Patent Document 1, a heat exchange pipe such as a spiral is embedded in the thickness of the motor housing, and a coolant such as water or oil (heat exchange) The motor housing is cooled by passing the medium) through the heat exchange pipe.

  In other words, a motor housing as one heat exchanger is constituted by a motor housing main body as a heat transfer body and a heat exchange pipe for cooling the main body.

ACT 6-44378

  In the known technique disclosed in Patent Document 1, as a method for embedding a heat exchange pipe, a method is adopted in which the pipe is arranged in a mold and cast into the main body during molding of the motor housing main body.

  However, since the position of the heat exchange pipe cannot be sufficiently fixed at the time of casting, the heat exchange pipe easily moves in the length direction and radial direction due to the inflow pressure of the casting water (molten material), and it is difficult to maintain the accuracy of the pipe position. Thus, there is a problem that the heat exchange effect as designed cannot be obtained.

  Such problems are not limited to the motor housing of an electric motor, but include heat exchangers for cooling or warming up electric and electronic devices mounted on construction machines such as excavators, for example, to transfer heat by casting heat exchange pipes. It is in general heat exchangers embedded in the body, and the solution of this point was awaited.

  Therefore, the present invention provides a heat exchanger that can improve the heat exchange efficiency by improving the position accuracy of the pipe while casting the heat exchange pipe into the heat transfer body, and a method for manufacturing the heat exchanger. .

  As means for solving the above problems, in the invention (heat exchanger) according to claim 1, a heat exchange pipe through which a heat exchange medium is passed is fixed to a pipe mounting surface of a base, and the pipe mounting surface side of the base is fixed to the base. The heat transfer body is formed by molding in a state where the heat exchange pipe is embedded.

  According to this configuration, the heat exchange pipe is fixed to the base, the heat exchange pipe does not move unless the base moves due to the inflow pressure of the casting water during casting, and the position of the base is fixed easily and reliably compared to the pipe. By being able to perform, the movement of the heat exchange pipe at the time of casting can be prevented, and the position accuracy can be maintained.

  Thereby, the heat exchange effect as designed as a heat exchanger can be acquired.

  Here, in a cylindrical heat exchanger such as a motor housing of an electric motor, the base is cylindrical, and the heat exchange pipe extends along the outer peripheral surface on the outer peripheral surface of the base as the pipe mounting surface. The heat transfer body (housing main body in the case of a motor housing) may be molded into a cylindrical shape while being fixed in a bent state (claims 2 and 3).

  In this case, it is desirable that the heat exchange pipe is spirally wound around and fixed to the outer peripheral surface of the cylindrical base.

  In this way, in addition to the heat exchange action acting on the entire circumference, the inner circumference side of the heat exchange pipe is restricted by the cylindrical base, and it is only necessary to prevent movement of the pipe in the diameter increasing direction. The pipe can be easily fixed and the positional accuracy can be further increased.

  In the present invention, it is preferable that a plurality of concave grooves intersecting with the heat exchange pipe are provided on the pipe mounting surface of the base.

  According to this configuration, at the time of casting, the casting hot water is filled into the concave groove, and at the portion where the concave groove and the heat exchange pipe intersect, the hot water overflowing from the concave groove is between the pipe and the pipe mounting surface of the base. It fills in the gaps that are formed.

  As a result, it is possible to prevent an air layer (air nest) from being formed in the gap, increase the heat transfer area, and increase the heat exchange efficiency.

  On the other hand, in the inventions (manufacturing methods) of claims 5 and 6, the heat exchange pipe through which the heat exchange medium is passed is fixed to the pipe attachment surface of the base, and the base is attached as one of the molds. A heat exchanger in which the heat exchange pipe is embedded is manufactured by molding a heat transfer body on the surface side.

  According to this method, since the heat transfer body is molded using the base as one of the molds, the mold configuration can be simplified and the molding can be facilitated.

  In this case, in a cylindrical heat exchanger such as a motor housing of an electric motor, the base is cylindrical, and the heat exchange pipe is provided along the outer peripheral surface on the outer peripheral surface of the base as the pipe mounting surface. The base plate may be fixed in a bent state, and a cylindrical heat transfer body may be molded on the outer peripheral surface side of the base using the base as an inner mold.

  According to the present invention, the heat exchange efficiency can be improved by increasing the positional accuracy of the heat exchange pipe.

It is sectional drawing of the whole electric motor which shows 1st Embodiment of this invention which applied the motor housing. It is the II-II sectional view taken on the line of FIG. It is a perspective view of the base and cooling pipe which constitute the motor housing as a heat exchanger concerning a 1st embodiment. It is sectional drawing which shows the mold forming state of a motor housing. It is sectional drawing of the whole electric motor which shows 2nd Embodiment of this invention. It is a perspective view of the base and cooling pipe which comprise the motor housing which concerns on 3rd Embodiment of this invention. It is a perspective view of the base and cooling pipe which concern on 4th Embodiment of this invention which applied the heat exchanger for electrical / electronic devices. It is sectional drawing of the heat exchanger which concerns on 4th Embodiment.

  1 to 6 are first to third embodiments in which a motor housing of an electric motor is applied, and FIGS. 7 and 8 are fourth embodiments in which a heat exchanger for cooling or warming up electric / electronic devices is applied. Each form is shown.

1st Embodiment (refer FIGS. 1-4)
The electric motor shown in FIGS. 1 and 2 includes a rotor 2 that rotates about an electric motor shaft 1, a stator 3 that is disposed on the outer periphery of the rotor 2, and a cylindrical motor housing in which the stator 3 is attached to the inner peripheral side. H and covers 5 and 6 attached to both ends of the motor housing H in the axial direction.

  In FIG. 1, 3 a is a coil of the stator 3.

  The motor housing H is made of a cylindrical motor housing main body 4 molded by a heat conductive material such as aluminum, and a high-strength material such as cast iron, steel, and stainless steel integrally provided on the inner peripheral side of the main body 4. A cylindrical base 7 as a strength member, and a cooling pipe (a heat exchange pipe embedded in the thickness of the housing in a spirally wound state on the outer peripheral surface of the base 7 over almost the entire length in the axial direction ( Round pipe) 8.

  Hereinafter, the motor housing H is abbreviated as “housing”, and the motor housing main body 4 is abbreviated as “housing main body”.

  Both ends 8a and 8b of the cooling pipe 8 are led out of the housing body 4 with one being a refrigerant inlet and the other being a refrigerant outlet, and refrigerant such as water and oil supplied from the outside is passed through the cooling pipe 8 as a refrigerant passage. As a result, the housing body 4 is cooled.

  In other words, the housing body 4 as the heat transfer body, the base 7 and the cooling pipe 8 constitute a housing H as one heat exchanger, and the stator heat is absorbed by the housing H or externally through the housing H. To be released.

  In addition, a large number of concave grooves 9 extending over the entire length in the base axial direction are provided on the outer peripheral surface of the base 7 at regular intervals in the circumferential direction.

  The cooling pipe 8 is wound around the base outer peripheral surface in a bent state along the outer peripheral surface of the base and is wound around the base outer peripheral surface, and is fixed by welding or the like at a plurality of locations in the length direction (or the full length portion is also acceptable). In this state, the housing body 4 is cast into the main body 4 during molding.

  That is, as shown in FIG. 4, in the outer mold 10 of the mold, the base 7 on which the cooling pipe 8 is wound and fixed is concentrically arranged as the inner mold, and the position of the outer mold 10 and the base 7 is fixed. In the meantime, casting water 4A as a raw material of the housing body 4 is poured and filled to be solidified.

  In FIG. 4, reference numeral 11 denotes a lid that closes the upper surface opening of the outer mold 10.

  The position of the base 7 can be fixed, for example, by providing a convex portion 10a on the bottom surface of the outer mold 10 and fitting the lower portion of the base 7 into the convex portion 10a as shown in the figure.

  As a result, the cylindrical housing main body 4 is molded, and at the same time, the base 7 is integrated on the inner peripheral side of the main body 4 and the cooling pipe 8 is spirally embedded in the wall thickness. , 2 as a heat exchanger is configured.

  In this case, the cooling pipe 8 is fixed to the base 7, and the cooling pipe 8 does not move unless the base 7 moves at the time of casting, and the position of the base 7 in the mold is fixed by the convex portion 10a in the figure. As a result, the movement of the cooling pipe 8 during casting can be reliably prevented, and the positional accuracy can be maintained.

  Thereby, the heat exchange effect as designed as a heat exchanger can be acquired.

  Further, since the cooling pipe 8 is spirally wound and fixed around the outer peripheral surface of the base 7, in addition to the heat exchanging (cooling) action acting on the entire circumference, the inner peripheral side of the cooling pipe 8 is cylindrical. Since it is only necessary to be restricted by the base 7 and prevent the movement of the pipe 8 in the diameter-expanding direction, the cooling pipe 8 can be easily fixed and the positional accuracy can be further increased.

  Further, since a plurality of concave grooves 9 intersecting with the cooling pipe 8 are provided on the outer peripheral surface (pipe mounting surface) of the base 7, at the time of casting, the casting water 4A is formed into the concave grooves 9 as shown in FIG. Filled and filled in the gaps formed between the pipes 8 and the outer peripheral surface of the base, the hot water overflowing from the grooves 9 is filled at all portions where the grooves 9 and the heat exchange pipe intersect. .

  This prevents the formation of an air layer (air nest) in the gap, thereby increasing the heat transfer area and increasing the heat exchange efficiency.

  On the other hand, as an effect of the housing manufacturing method, since the housing body 4 is molded on the outer peripheral surface of the base using the base 7 as one of the molds (in this case, the inner mold), the mold configuration is simplified and the molding is facilitated. Can be realized.

Second and third embodiments (see FIGS. 5 and 6)
Only differences from the first embodiment will be described.

  In the second embodiment shown in FIG. 5, the cooling pipe 8 is formed of a square pipe, and is wound around and fixed to the outer peripheral surface of the base 7 in a spiral manner as in the first embodiment.

  In this way, the contact area between the outer peripheral surface of the base 7 and the cooling pipe 8 can be increased, and the cooling efficiency can be increased.

  In the third embodiment shown in FIG. 6, the cooling pipe 8 is not spiral around the entire circumference of the base outer peripheral surface, but within a certain angular range in the circumferential direction (substantially a half-circular portion in the example), and the base axial direction. Are fixed in a state of being bent back and forth and in close contact with the outer peripheral surface of the base.

  In this case, the concave grooves 9 are provided in the circumferential direction of the outer peripheral surface of the base.

  In this way, even when the cooling pipe 8 cannot be wound around the entire circumference of the base due to layout restrictions or the like, the refrigerant passage can be secured in the remaining range.

  Note that the cooling pipe 8 may be fixed in a bent state in which the cooling pipe 8 is bent back and forth in the circumferential direction with respect to the outer peripheral surface of the base.

  In this case, the concave grooves 9 are provided in the axial direction of the outer peripheral surface of the base.

Fourth embodiment (see FIGS. 7 and 8)
In the fourth embodiment, a heat exchanger for cooling or warming up an electric / electronic device such as an inverter, a controller, and a capacitor mounted on a shovel is an application target.

  That is, a plurality of concave grooves 13 are provided in parallel on a single surface (pipe mounting surface) of the thick plate-like base 12 at a predetermined interval, and the heat exchange pipe 14 intersects the concave grooves 13. And a heat exchanger plate 15 in which the heat exchange pipe 14 is embedded in the wall thickness is formed by molding a heat transfer plate 15 as a heat transfer body on one side of the base 12.

  In FIG. 7, reference numerals 14 a and 14 b denote both end portions as heat exchange medium inlets or outlets of the heat exchange pipe 13.

  As with the motor housing, the heat exchanger 16 can also prevent the movement of the heat exchange pipe 14 due to the inflow pressure of the poured hot water and maintain its positional accuracy.

  Further, by providing the concave grooves 13 intersecting with the heat exchange pipe 14, it is possible to increase the heat transfer area by spreading cast hot water over the gap between the heat exchange pipe 14 and the base 12, and the base 12. The point that can be used as a part of the mold (for example, the lower mold) is the same as in the first to third embodiments.

  In this case, similarly to the second embodiment, the heat exchange pipe 14 may be a square pipe.

  By the way, this invention can be widely applied to the heat exchanger with which a heat exchange pipe is embed | buried, such as a heat exchange sheet | seat for floor heating other than the said embodiment.

H motor housing 4 housing main body as heat transfer body 4A pouring hot water 7 base 8 cooling pipe as heat exchange pipe 9 concave groove 10 outer mold 10a convex portion for fixing base position 12 base 13 concave groove 14 heat exchange pipe 15 heat transfer Board 16 heat exchanger

Claims (6)

  A heat exchange pipe through which a heat exchange medium is passed is fixed to a pipe mounting surface of a base, and a heat transfer body is molded on the pipe mounting surface side of the base while the heat exchange pipe is embedded. A heat exchanger characterized by   The base is cylindrical, the heat exchange pipe is fixed to the outer peripheral surface of the base as the pipe mounting surface in a bent state along the outer peripheral surface, and the heat transfer body is molded into a cylindrical shape. The heat exchanger according to claim 1.   The heat exchanger according to claim 2, wherein the heat exchange pipe is fixed by being spirally wound around an outer peripheral surface of the cylindrical base.   The heat exchanger according to any one of claims 1 to 3, wherein a plurality of concave grooves intersecting with the heat exchange pipe are provided on a pipe mounting surface of the base.   The heat exchange pipe through which the heat exchange medium is passed is fixed to the pipe mounting surface of the base, and the heat exchange is performed by molding the heat transfer body on the pipe mounting surface side of the base using the base as one of the molds. A method of manufacturing a heat exchanger, characterized by manufacturing a heat exchanger in which a pipe is embedded.   The base is cylindrical, the heat exchange pipe is fixed to the outer peripheral surface of the base as the pipe mounting surface in a bent state along the outer peripheral surface, and the base is used as an inner mold and is cylindrical on the outer peripheral surface side of the base 6. The method of manufacturing a heat exchanger according to claim 5, wherein the heat transfer body is molded.

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