JPH11145637A - Housing for servo amplifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a housing for a servo amplifier, in which a heat sink and a resin cover can be joined without a joining means, and the joining part thereof is made rugged. SOLUTION: A heat sink 2 and a resin cover 3 are formed in a body in a molding step and joined without a joining means. At the same time stress generated at the resin part is reduced and the joining part thereof is made rugged. In this way, a frame of a servo amplifier includes the heat sink 2 and the resin cover 3, and the heat sink 2 has at least a first projected, recessed or uneven fitting part 11. The resin cover 3 has a second fitting part 12 to be fitted with the first fitting part 11. The second fitting part 12 is formed near to the first fitting part 11 at the same time in the cover molding step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing for housing a servo amplifier circuit.

[0002]

2. Description of the Related Art In general, a circuit portion including a printed circuit board and a semiconductor element constituting an amplifier is housed in a housing, thereby protecting internal components and maintaining good appearance. In such an amplifier, since the servo amplifier uses a power semiconductor such as an IGBT, a large amount of heat is generated from internal components. Therefore, the servo amplifier is configured to include a heat sink (radiator) to radiate heat to the outside of the amplifier. I have.

For this reason, the housing of the servo amplifier includes a heat sink and a cover as components.

FIGS. 10 and 11 are schematic cross-sectional views for explaining the housing of a conventional servo amplifier. In the conventional configuration shown in FIG.
And a resin cover 3, and a printed circuit board 4 and a power semiconductor element 5 are housed therein. In the case of the servo amplifier, the heat sink 2 and the resin cover 3 are separately formed, and are connected to each other by screws 6.

[0005] In another conventional structure shown in FIG.
The heat sink 2 and the resin cover 3 forming the housing of the servo amplifier are formed separately from the heat sink 2 and the resin cover 3 in the same manner as in FIG. The snap 7 is hooked to the end of the heat sink 2 to connect the heat sink 2 to the resin cover 3. Generally, an aluminum heat sink is used.

[0006]

In a conventional servo amplifier housing, a heat sink and a resin cover are connected to each other by using fixing means such as screw fastening or resin snapping. There is a problem that a fixing means and a tool therefor are required, and a problem that the number of assembling steps for connection is increased.

Also, there is a large difference in mechanical strength between an aluminum heat sink and a resin cover.
When fixing means such as screw tightening or snapping of resin is used, stress is applied to the resin portion, the strength of the joint portion is reduced, and there is also a problem that resin cracking is caused (A in FIG. 10 and FIG. 10). B).

Accordingly, the present invention solves the problems of the conventional servo amplifier housing and provides a servo amplifier housing capable of connecting a heat sink and a resin cover without using fixing means. It is another object of the present invention to provide a servo amplifier housing in which the strength of the joint between the heat sink and the resin cover is high.

[0009]

The housing of the servo amplifier according to the present invention forms the heat sink and the resin cover at the same time by integrally forming the heat sink and the resin cover without using fixing means. Also, the strength of the joint between the heat sink and the resin cover is increased by reducing the stress generated in the resin portion.

Therefore, the housing of the servo amplifier according to the present invention comprises:
In order to simultaneously mold the heat sink and the resin cover integrally, in a servo amplifier housing provided with a heat sink and a resin cover, the heat sink has a convex or concave shape or an uneven shape on at least a part of a bonding surface to be bonded to the cover. And the resin cover is provided with a second engaging portion that engages with the first engaging portion. Are formed in contact with the engaging portions.

The heat sink is a radiator for radiating heat in the housing to the outside, and is formed of a material having good heat conductivity such as aluminum, and forms a housing of the servo amplifier together with a resin cover.

The resin cover covers the circuit components of the servo amplifier and protects the components and forms a good appearance.

According to the servo amplifier housing of the present invention, when the resin cover is formed, the resin cover is formed so as to be in contact with the first engaging portion formed on the heat sink joining surface. By this molding, a second engaging portion corresponding to the first engaging portion is formed simultaneously with the molding at a portion where the resin cover is in contact with the first engaging portion. By the engagement of the two engaging portions, the heat sink and the resin cover are joined.

Therefore, the heat sink and the resin cover are integrally molded at the same time, and the integral molding simultaneously joins the heat sink and the resin cover. This eliminates the need for fixing means and tools for it,
Further, since no stress is generated in the resin portion due to the fixing, the strength of the joint is increased (corresponding to claim 1).

One aspect of the housing of the servo amplifier of the present invention is as follows.
The first engagement portion on the heat sink side is a groove formed along the entire circumference or a part of the outer peripheral surface of the heat sink. For example, the groove is provided when the external shape of the aluminum heat sink is formed. Can be formed by simple shape processing.
Corresponding to).

Another aspect of the housing of the servo amplifier according to the present invention is that the heat sink has a block structure of a component having at least a first engagement portion, and the heat sink is formed by using a plurality of the blocks. The connection between the blocks can be performed by the engagement between the first engagement portion on the heat sink side and the second engagement portion of the resin cover. As a result, blocks having different heat dissipation characteristics can be used, and by combining the blocks having different heat dissipation characteristics, a servo amplifier housing having a heat sink corresponding to the heat dissipation characteristics of the servo amplifier can be configured. 3).

In another aspect of the housing of the servo amplifier of the present invention, the cover is formed by molding a molten resin. Thus, when the resin cover is formed, by disposing the heat sink in the mold, the resin cover and the heat sink can be joined by cover molding (corresponding to claim 4).

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 3 is a cross-sectional view of the servo amplifier housing of FIG. 1, a partial perspective view of the servo amplifier housing of FIG. 2, and a cross-sectional view of FIG. It will be described using FIG.

In FIG. 1, a housing 1 includes a heat sink 2
And a resin cover 3 for accommodating the printed circuit board 4 and the power semiconductor element 5 therein. The heat sink 3 can be made of aluminum and includes a base 21 in contact with a heat-generating portion such as the power semiconductor element 5 and fins 22 for releasing heat to the outside. A concave groove 23 is formed in the outer peripheral portion of the base 21 portion of the heat sink 3, thereby forming a first engaging portion. This groove 23 may be formed over the entire outer periphery of the base 21,
Also, it can be formed only on a part of the peripheral portion.

The resin cover 3 is formed at least at a position in contact with the groove 23 formed in the base 21 of the heat sink 2, and a second engaging part of the groove 23 is engaged with the first engaging portion 11. The joint 12 is formed. The joining of the heat sink 2 and the resin cover 3 can be performed by the engagement of the first engagement portion 11 and the second engagement portion 12.

FIG. 2 is a perspective view showing a portion of the base 21 of the heat sink 2 and a portion of the resin cover 3. By molding the resin cover 3, the second engaging portion 12 having a convex shape corresponding to the groove 23 of the heat sink 2 is formed on the inner surface of the resin cover 3 simultaneously with the molding. Therefore, the groove 23 that is the first engaging portion 11 and the second engaging portion 1
2, the molding is performed in the engaged state.

FIG. 3 is a diagram for explaining a process of forming the housing of the servo amplifier. The housing can be formed by molding. In the formation of the housing by this mold formation, at least the first engagement portion 11 of the heat sink 2 is housed inside and the mold 6 for molding the resin cover 3 is used. FIG. 3 shows an example of a configuration in which the heat sink 2 is stored in the mold 6. However, the configuration is not necessarily a configuration in which the entire heat sink 2 is stored, and a configuration in which the first engagement portion 11 of the heat sink 2 is stored inside. It suffices if it has a portion and a component for forming the resin cover 3. In FIG. 3, the mold 6 is indicated by oblique lines.

When the heat sink 2 is set on the mold 6, a gap is formed between the mold 6 and the heat sink 2 between the mold 6 and the heat sink 2. This gap becomes a molded part of the resin cover 3. When the molten resin is injected into the gap, the resin fills the gap and the first heat sink 2
The engaging portion 11 is deformed according to its shape. After the resin has hardened, the mold 6 is removed, whereby the molding of the resin cover 3 is completed. At this time, the first heat sink 2
The engaging portion 11 and the second engaging portion 12 of the resin cover 3 are molded in an engaged state, whereby the heat sink 2 and the resin cover 3 are integrally molded in a state of being simultaneously joined.

FIG. 4 is a perspective view for explaining a second configuration example of the embodiment of the present invention. Similar to FIG. 2, the base 21 of the heat sink 2 and a part of the resin cover 3 are shown. I have. FIG. 4A is a configuration example in which the first engagement portion 24 of the heat sink 2 is formed in a convex shape. In this configuration example, the second engagement portion 12 'of the resin cover 3 is formed in a concave shape corresponding to the convex shape 24 on the first engagement portion side.

FIG. 4B shows the first heat sink 2.
This is a configuration example in which the engaging portion 24 is formed in a convex shape and a concave shape. In this configuration example, the second engagement portion 12 ′ of the resin cover 3 is
It is formed into a convex shape and a concave shape corresponding to the concave shape groove 23 and the convex shape 24 on the first engagement portion side. Note that the depth of the groove 23 can be set arbitrarily. According to the above configuration, similarly to the first configuration example, the first engagement portion 11 and the second engagement portion 12 are molded in an engaged state.

FIG. 5 is a sectional view for explaining a third configuration example of the embodiment of the present invention. The third configuration example is a configuration in which the height of the resin cover is reduced, and the other configuration is the same as the third configuration example. According to this configuration example, the resin cover 3 'covers only the lower part of the circuit component, and the higher part is in a state where external interference is possible, so that the maintainability of the circuit component can be improved.

FIGS. 6 and 7 are a perspective view and a cross-sectional view of a heat sink for explaining a fourth configuration example of the embodiment of the present invention. In the fourth configuration example, the heat sink 2 is subdivided into a plurality of blocks, and the subdivided blocks are combined and combined to form a heat sink. The subdivided block part is the base part 2
1 'has at least a first engaging portion 11', and a radiation fin 22 'can be provided arbitrarily. The block without the heat radiating fins 22 'has only the base portion, and can be used as a coupling material for other blocks. FIG. 6 shows a case where each block has the same shape and the same dimensions, and the radiation fins 22 ′ are respectively shown.
Is shown.

FIGS. 8 and 9 are a perspective view and a sectional view of a heat sink for describing a fifth configuration example of the embodiment of the present invention. The fifth configuration example is similar to the fourth configuration example,
The heat sink 2 is subdivided into a plurality of blocks, and the subdivided blocks are combined and combined to form a heat sink. The subdivided block portion is configured to have at least first engagement portions 11 'and 11''on the base portions 21' and 21 '', and the radiation fins 22 'and 22''are provided arbitrarily. Can be. The block without the heat radiating fins 22 'has only the base portion, and can be used as a coupling material for other blocks.

Each block of the fifth configuration example includes a base unit 2
1 ′, 21 ″ pitch and radiation fins 22 ′, 2
This is a configuration in which the height of 2 '' is different. By varying the pitch of the blocks and the height of the fins, different heat radiation characteristics can be obtained.

According to this configuration, blocks having different heat radiation characteristics are combined in accordance with circuit components having different heat values,
Thereby, a heat sink can be formed.

FIG. 9 shows a configuration in which a block corresponding to the heat radiation characteristic of the power semiconductor element 5 'and a block corresponding to the heat radiation characteristic of the power semiconductor element 5''are combined.
This combination can be set arbitrarily according to the heat generation characteristics of the circuit components. When the resin cover is molded, a combination of the blocks is set and arranged, and is integrally molded together with the cover molding.

According to the fourth and fifth configurations, the shape and heat radiation characteristics of the heat sink can be set arbitrarily.
It is possible to design with a greater degree of freedom than when one heat sink is formed by extrusion or die casting.

The heat sink and the block used for the housing of the servo amplifier of the present invention are extruded products, processed products,
A processed product of an aluminum plate or an aluminum die-cast can be used.

[0034]

As described above, according to the servo amplifier housing of the present invention, the heat sink and the resin cover can be connected without using the fixing means. Can increase the strength of the joint portion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a housing of a servo amplifier for describing a first configuration example of an embodiment of the present invention.

FIG. 2 is a partial perspective view of a housing of a servo amplifier for describing a first configuration example of the embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a first example of a configuration of the embodiment of the present invention when a cover of a housing of a servo amplifier is formed.

FIG. 4 is a perspective view illustrating a second configuration example of the embodiment of the present invention.

FIG. 5 is a cross-sectional view for explaining a third configuration example of the embodiment of the present invention.

FIG. 6 is a perspective view of a heat sink for describing a fourth configuration example of the embodiment of the present invention.

FIG. 7 is a cross-sectional view of a heat sink for describing a fourth configuration example of the embodiment of the present invention.

FIG. 8 is a perspective view of a heat sink for describing a fifth configuration example of the embodiment of the present invention.

FIG. 9 is a cross-sectional view of a heat sink for describing a fifth configuration example of the embodiment of the present invention.

FIG. 10 is a schematic sectional view illustrating a housing of a conventional servo amplifier.

FIG. 11 is a schematic cross-sectional view illustrating a housing of a conventional servo amplifier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Heat sink 3, 3 'Resin cover 4 Printed circuit board 5 Power semiconductor element 6 Type 11, 11', 11 '' 1st engagement part 12 2nd engagement part 21, 21 ', 21' ' Base 22, 22 ′, 22 ″ Radiation fin 23 Groove 24 Convex portion

Claims (4)

[Claims] In a servo amplifier housing provided with a heat sink and a resinous cover, the heat sink has a first engaging portion having a convex or concave shape or an uneven shape on at least a part of a joining surface joined to the cover. Wherein the resin cover includes a second engagement portion that engages with the first engagement portion, and the second engagement portion is formed in contact with the first engagement portion simultaneously with molding the cover. Housing for servo amplifier. 2. The servo amplifier housing according to claim 1, wherein said first engagement portion is a groove formed along the entire circumference or a part of the outer peripheral surface of the heat sink. 3. The heat sink includes a plurality of components having at least a first engaging portion, and the plurality of components are formed by engaging the first engaging portion with a second engaging portion of the resin cover. The housing of the servo amplifier according to claim 1, wherein the coupling is performed. 4. The servo amplifier housing according to claim 1, wherein said cover molding is a molding of a molten resin.