Housing and device for housing heat-generating component

Abstract

To provide a housing having high heat dissipation without a molding problem.SOLUTION: A housing 1 for housing a heat-generating component therein includes a heat sink unit 11, and the heat sink unit 11 includes: a plurality of fins 111 protruding to the outside of the housing 1; a vent hole 112 communicating between the inside and the outside of the housing 1; a contact portion 113a in thermal contact with the heat-generating component; a convex portion protruding to the inside of the housing; and a hollow portion 114 recessed from the outside of the housing 1 toward a tip end portion of the convex portion 113. At least one portion of the one or two or more fins 111a of the plurality of fins 111 is provided in the thinned portion 114, and a tip portion of the one or two or more fins 111a provided at least in the thinned portion 114 protrudes from the recess of the thinned portion 114.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a housing for accommodating a heat-generating component therein, and to a device including the housing and the heat-generating component. [Background technology]

[0002] A heat sink is generally provided in a housing to dissipate heat generated by heat-generating components such as a circuit board and a light source inside the housing to the outside of the housing. One example of the shape of the heat sink is known, for example, to have a plurality of fins for heat dissipation that protrude outside the housing and a protrusion that protrudes inside the housing and is in thermal contact with the heat-generating components inside the housing (Patent Document 1).

[0003] A housing with a heat sink unit is generally manufactured by manufacturing the housing unit without the heat sink unit and the heat sink unit as separate parts and then attaching the heat sink unit to the housing unit (Patent Document 1), or by molding them together at once using a material with high heat dissipation properties, as an integrated molded product with the housing unit and heat sink unit. When a material with high heat dissipation properties is used for the housing unit, the housing unit also has a heat sink function in addition to the heat sink unit.

[0004] Generally, when components having large or thick portions are manufactured by molding, such as casting, molding problems such as the occurrence of porosity are likely to occur. For example, the occurrence of porosity reduces the mechanical properties (strength, etc.) and heat dissipation of the component, and the component with the porosity must be discarded. When porosity occurs on the surface of a component, it is visible from the outside, but it is difficult to see porosity that occurs inside the component. For this reason, the presence or absence of porosity is usually inspected using X-rays, etc., but this is costly. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 044731 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-described shape of the heat sink portion, for example, if the protrusion is large in volume, molding problems such as the occurrence of voids in the protrusion are likely to occur when the heat sink portion is manufactured by molding. Molding problems become particularly pronounced when the housing and the housing including the heat sink portion are molded together at one time. The heat sink portion and the housing including the heat sink portion can also be manufactured by cutting out a block of material. In this case, voids do not occur, but from the viewpoint of manufacturing costs, manufacturing the heat sink portion and the housing including the heat sink portion by cutting is not suitable for mass production.

[0007] An object of the present invention is to provide a housing that has no molding problems and has high heat dissipation properties. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a housing having a heat sink part for accommodating a heat-generating component therein, The heat sink portion is a plurality of fins protruding outward from the housing; a ventilation hole communicating between the inside and the outside of the housing; a protrusion that protrudes into the housing and is in thermal contact with the heat-generating component; a recessed portion recessed from the outside of the housing toward the tip of the protrusion; Equipped with At least a portion of one or more of the plurality of fins is provided in the hollowed portion, The housing has one or more fins at least a portion of which is provided in the cutout portion, the tips of which protrude from the recesses of the cutout portion. [Effects of the Invention]

[0009] According to the present invention, a housing with high heat dissipation properties is provided without any molding problems. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a display device including a housing according to one embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the display device shown in FIG. [Figure 3] FIG. 3 is a plan view of the housing shown in FIG. 1 as seen from the back side. [Figure 4] FIG. 4 is an enlarged view of region B in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, embodiments of the present invention may be described using mutually orthogonal x, y, and z axes as appropriate. The x axis extends in the left-right direction in FIG. 2, the y axis extends in the up-down direction in FIG. 2, and the z axis extends perpendicular to the xy plane. The direction in which the arrows indicating each of the x, y, and z axes point is the + (plus) direction of each axis, and the opposite direction is the - (minus) direction. For example, the + direction along the z axis is referred to as the +z direction.

[0012] FIG. 1 illustrates a display device including a housing 1, a circuit board 2 as a heat-generating component, a heat-conducting member 3, a display unit 4, a protective cover 5, a frame 6, and a connector 7. The display device illustrated in FIG. 1 is an example in which the housing 1 is applied to a display device mounted on a vehicle, such as a vehicle-mounted construction machine. When the display device is in operation, the +y direction is generally upward. The viewer's side of the display device is referred to as the front side, and the opposite side of the viewer is referred to as the back side. FIG. 2 is a perspective view of the display device illustrated in FIG. 1, FIG. 3 is a plan view of the housing 1 illustrated in FIG. 1 from the back, and FIG. 4 is an enlarged view of region B in FIG. 1. Note that FIG. 1 is a 180° rotated view of the cross section taken along line AA in FIG. 2.

[0013] In the drawings, the scale and aspect ratios have been changed as appropriate to facilitate understanding, and detailed structures and some components (screws and their threaded engagement portions, connecting means, adhesive means, cohesive means, etc.) have been omitted. In addition, in the drawings, for ease of viewing, reference symbols may be assigned to only some of the components that exist with the same attribute.

[0014] In this specification, terms specifying shapes and geometric conditions and the degree thereof (e.g., "plate," "rectangle," "surface," "parallel," "vertical," "plumb," and "continuous"), values, directions (e.g., "flow direction" and "up-down direction"), etc. are not bound by strict meanings, but are interpreted to include a range of degrees to which similar functions can be expected.

[0015] <Case> 1 to 3 show a housing 1 according to one embodiment of the present invention. The housing 1 has a general shape of a flat, closed-bottomed rectangular cylinder with an open front side. The housing 1 has a heat sink section 11 on the back side for dissipating heat inside the housing 1 to the outside. A display means 4, a protective cover 5, and a frame 6 are installed in the opening on the front side of the housing 1 so as to cover the opening of the housing 1.

[0016] The housing 1 is manufactured as a one-piece molded product that includes a housing portion and a heat sink portion 11 by molding the housing 1 integrally at one time using a material with high heat dissipation properties. Because the entire housing 1 is made of a material with high heat dissipation properties, portions other than the heat sink portion 11 also have a heat dissipation function.

[0017] The material with high heat dissipation properties is not particularly limited as long as it can function as a heat sink and allows a member formed using the material to have a given strength. Examples of the material with high heat dissipation properties include materials that are mainly composed of metals with high heat dissipation properties (e.g., aluminum, copper) or alloys thereof, graphite, or ceramics.

[0018] For a given purpose, the housing 1 may be subjected to a surface treatment. For example, if the housing 1 is mainly made of an aluminum alloy, the housing 1 or the heat sink portion 11, particularly the fins 111, may be subjected to a surface treatment such as plating or alumite treatment in order to improve heat dissipation.

[0019] The housing 1 can be manufactured by mold forming, for example, casting (plaster casting, die-casting, etc.) or cutting. When the housing 1 is mass-produced by cutting a block of material, the mass production costs tend to be high. Therefore, it is preferable that the housing 1 be mass-produced by mold forming, for example, casting (plaster casting, die-casting, etc.).

[0020] As shown in FIG. 3, the housing 1 may have screw holes on the back side for attaching the housing 1 to an external component, and a connector connection opening 12 for connecting the circuit board 2 housed inside the housing 1 to an external component.

[0021] 1 to 3, the heat sink 11 includes a plurality of plate-like fins 111 protruding to the outside of the housing 1, ventilation holes 112 communicating the inside and outside of the housing 1, a protrusion 113 protruding to the inside of the housing 1 and in thermal contact with the circuit board 2, which is a heat-generating component, and a first cutout 114 (hereinafter simply referred to as cutout 114) as a recess recessed from the outside of the housing 1 toward the tip of the protrusion 113. At least a portion of one or more of the plurality of fins 111 is also provided on the surface of the cutout 114 (hereinafter, the fin 111 at least a portion of which is provided in the cutout 114 is also referred to as the fin 111a). The tip of the one or more fins 111a at least a portion of which is provided in the cutout 114 protrudes from the recess of the cutout 114.

[0022] As described above, when components having large or thick portions are manufactured by die molding, molding problems such as the occurrence of porosity are likely to occur. Large or thick portions are areas where porosity that is difficult to visually identify from the outside can occur during manufacturing.

[0023] As described above, the protrusion 113 of the heat sink 11 can be a large portion in volume. However, as shown in Figures 1 and 3, the heat sink 11 is hollowed out from the outside of the housing 1 toward the tip of the protrusion 113, and has a hollowed-out portion 114. This keeps the volume of the protrusion 113 small, and therefore prevents voids from forming inside it.

[0024] 1 to 3, the heat sink 11 has a structure in which a portion thereof is raised by one step on the rear side of the housing 1, and this raised structure can be a thick portion. However, in this embodiment, the inside of the raised structure is hollowed out as shown in FIG. 1, and the heat sink 11 has a second hollowed out portion 115. As a result, the raised structure of the heat sink 11 does not have a thick portion, and therefore, voids are less likely to occur inside.

[0025] In the present invention, it is preferable that the entire housing 1 and the large-volume or thick-walled portions to be removed are removed so that problematic voids do not occur inside them and that even if voids do occur in them, the voids are visible from the outside. That is, for example, it is preferable that the thickness of the protrusion 113 is such that problematic voids do not occur inside the protrusion 113 and that even if problematic voids do occur in the protrusion 113, the voids are visible from the outside. The same applies to the thicknesses of the other portions of the housing 1. In this embodiment, the thickness of the protrusion 113 is formed to be approximately the same as the thickness of the other portions of the housing 1.

[0026] 1 is in use (operated), heat generated from the circuit board 2, which is a heat-generating component, is conducted to the fins 111 protruding to the outside of the housing 1, either via the protrusions 113 in thermal contact with the circuit board 2 or without the protrusions 113. The heat conducted to the fins 111 is then released to the outside of the housing 1 by heat exchange between the fins 111 and the air in contact with the fins 111, and optionally by radiation from the fins 111. Furthermore, since the entire housing 1 is made of a material with high heat dissipation properties, heat is efficiently released to the outside of the housing 1 from parts of the housing 1 other than the fins 111. In this embodiment, heat is also generated from the display means 4 in addition to the circuit board 2. However, the heat generated from the display means 4 and released into the housing 1 is also released to the outside of the housing 1 via substantially the same path as the heat generated from the circuit board 2.

[0027] As shown in FIGS. 2 and 3 , the fins 111 are arranged such that the length direction of each fin 111 is parallel to the y direction (i.e., approximately vertical). Normally, warm air flows generally upward. Therefore, in this embodiment, air heated by heat dissipation from the housing 1 flows in the +y direction (i.e., the flow direction of thermal convection generated by heat dissipation from the housing 1 is the +y direction). Therefore, the length direction of each fin 111 is parallel to the flow direction of thermal convection, and the fins 111 do not impede thermal convection. This promotes the formation of the following thermal convection cycle. This thermal convection cycle is formed as follows: air heated by heat dissipation from the fins 111 flows upward; accordingly, air flows in from below; the air flowing in from below is also heated by heat dissipation from the fins 111 and flows upward. The formation of the thermal convection cycle prevents localized air pockets and heat dissipation saturation, achieving and maintaining a highly efficient heat dissipation state.

[0028] In the present invention, the shape, thickness, height, length, fin pitch, arrangement, etc. of the multiple fins 111 are not particularly limited, but are preferably designed so as not to inhibit thermal convection caused by heat dissipation when the display device is in use (operating). For example, the shape of the multiple fins 111 may be pin-shaped, corrugated, etc. The lengths (lengths in the longitudinal direction) of the multiple fins 111 may be the same or different from each other. Furthermore, in this embodiment, the multiple long plate-shaped fins 111 are arranged in parallel, but for example, each of the multiple fins 111 may be divided in the longitudinal direction, and short plate-shaped fins may be arranged in a staggered pattern.

[0029] 2 and 3, the heat sink part 11 has ventilation holes 112 that communicate between the inside and outside of the housing 1. When the display device is in use (operating), the air inside the housing 1 is heated by heat generated from the circuit board 2 and the like, causing the inside of the housing 1 to be in a state of high internal pressure. Therefore, the air heated by the heat generated from the circuit board 2 and the like is released to the outside of the housing 1 through the ventilation holes 112. In this way, the ventilation holes 112 prevent an increase in the internal pressure inside the housing 1 and also exhibit a heat dissipation function.

[0030] As shown in FIG. 3 , above the vent hole 112 (in the +y direction), there is a void formed between two adjacent fins 111 (hereinafter also referred to as fins 111b) among the multiple fins 111. That is, two or more fins 111b may be arranged above the vent hole 112, or one fin 111b may be arranged above the vent hole 112, and the adjacent fin 111b may be arranged shifted outward in the left-right direction from the space above the vent hole 112, or two fins 111b may be arranged with the space above the vent hole 112 sandwiched between them. The warm air released from the vent hole 112 flows upward and passes through the void formed between two adjacent fins 111b, which is expected to accelerate the thermal convection. This increases the frequency of heat exchange between the fins 111b and the air that comes into contact with the fins 111b.

[0031] As shown in Fig. 3, the vent hole 112 is disposed approximately in the center of the heat sink portion 11. This makes the heat convection in the center of the heat sink portion 11 faster than in the center portion, which is effective for heat exchange in the center of the heat sink portion 11, where heat dissipation is important. In addition, since heat is easily dissipated in the center portion, the average distance that heat travels from the entire housing 1 to the center portion is shorter, which is advantageous. Furthermore, this is expected to be more effective in preventing local temperature imbalances than when the vent hole 112 is formed in other parts.

[0032] The ventilation hole 112 may be provided with a waterproof porous film or the like to protect the circuit board 2. The waterproof porous film is a film that does not allow water to pass through but allows air to pass through.

[0033] The heat sink 11 includes a protrusion 113 that protrudes into the housing 1 and is in thermal contact with a heat-generating component (circuit board 2). Being in thermal contact with a heat-generating component means that the protrusion 113 is in direct contact with the heat-generating component or indirectly via a heat-conducting member 3 or the like. In this embodiment, as shown in FIG. 1 , the protrusion 113 is in contact at its tip with an IC (Integrated Circuit) chip 21 mounted on the circuit board 2 via the heat-conducting member 3. The IC chip 21 is a component with relatively low heat resistance among the components mounted on the circuit board 2. While the heat resistance of the portions of a standard circuit board 2 other than the IC chip 21 is approximately 120°C, the heat resistance of the IC chip 21 is approximately 80 to 100°C. The thermal contact between the protrusion 113 and the IC chip 21 allows efficient transfer of heat from the IC chip 21 to the protrusion 113, thereby protecting the IC chip 21 from heat.

[0034] The heat conducting member 3 is not limited as long as it is a member that efficiently conducts heat from the heat-generating component to the protrusions 113, and known members may be used. Examples of the form of the heat conducting member 3 include an adhesive, a sheet, etc. Examples of the material that constitutes the heat conducting member 3 include silicone rubber, ceramic, etc.

[0035] The heat sink 11 has a recessed portion 114 recessed from the outside of the housing 1 toward the tip of the protrusion 113. The surface of the recessed portion 114 is continuous with the surface on the exterior side of the housing 1. As described above, the recessed portion 114 keeps the volume of the protrusion 113 small, thereby preventing molding problems such as the occurrence of voids when the housing 1 is manufactured by molding.

[0036] At least a portion of one or more fins 111a among the multiple fins 111 is provided in the cutout portion 114. For example, "a portion of the fin 111a is provided in the cutout portion 114" refers to a state in which, as shown in FIG. 3, a portion of the fin 111a is provided in the cutout portion 114 and the remaining portion of the fin 111a is provided in a portion of the housing 1 that is continuous with the cutout portion 114. In other words, the base of the fin 111a extends across the cutout portion 114 and an adjacent region of the housing 1 that is continuous with the cutout portion 114. Alternatively, the entire fin 111a may be provided in the cutout portion 114. This may be the case, for example, when the fin 111a is a pin-shaped fin or a short fin. As shown in FIG. 3, the tip of one or more fins 111a at least partially provided in the cutout portion 114 protrudes from the recess of the cutout portion 114.

[0037] Here, the expected effect of the fins 111a provided in the cutout portions 114 will be explained in comparison with a case where the fins 111a are not provided in the cutout portions 114. If the fins 111a are not provided in the cutout portions 114, most of the heat conducted from the circuit board 2 to the protrusions 113 may be released into the recesses of the cutout portions 114. The air heated by the heat released into the recesses of the cutout portions 114 may remain in the recesses of the cutout portions 114, which may hinder heat dissipation in the cutout portions 114. On the other hand, if the fins 111a are provided in the cutout portions 114 so that their tips protrude from the recesses of the cutout portions 114, the heat conducted from the circuit board 2 to the protrusions 113 is efficiently released to the outside of the housing 1 via the fins 111a, particularly their tips. As a result, heat dissipation in the cutout portions 114 is not hindered.

[0038] In this embodiment, the case where the thermal convection is upward is illustrated, but the present invention is not limited to this. That is, the direction of the thermal convection may vary depending on the environment in which the housing 1 is used, and the installation direction of the housing 1 and the arrangement of the multiple fins 111 may be set so as not to hinder the thermal convection. Furthermore, the thermal convection may be natural convection as in this embodiment, or may be forced convection using a fan or the like.

[0039] <Device> 1 and 2 also show a display device including a housing 1. The display device includes the housing 1, a circuit board 2 as a heat-generating component, a heat-conducting member 3, a display means 4, a protective cover 5, a frame 6, and a connector 7. In describing the display device, descriptions of items that have already been described will be omitted.

[0040] The circuit board 2 is disposed behind the frame 6 and is generally parallel to the rear surface of the frame 6. The circuit board 2 is fixed to the rear surface of the frame 6 and the housing 1 by connecting means (not shown). The circuit board 2 mainly includes a control unit for controlling the display means 4. The control unit includes a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), etc., and executes predetermined arithmetic processing according to, for example, a program written in the ROM. The control unit acquires, for example, vehicle speed, engine RPM, various vehicle information, navigation information, etc. from the vehicle's electronic control unit (ECU) via various sensors. The control unit displays information on the display means 4 based on the acquired information. The control unit is an IC chip 21, known as a graphics display controller (GDC), that controls the display means 4. This IC chip 21 generates relatively high heat and has relatively low heat resistance. For this reason, the circuit board 2, and particularly the IC chip 21, require heat dissipation. The IC chip 21 is mounted on the +z side surface of the circuit board 2 and is connected to the protrusion 113 via the heat conduction member 3. The circuit board 2 is connected to an external component of the housing 1 via the connector 7 through the connector connection opening 12 of the housing 1.

[0041] The display means 4 includes a liquid crystal display element and a light source substrate. The liquid crystal display element is, for example, a TFT (Thin Film Transistor) type liquid crystal display panel formed by sealing liquid crystal molecules between a pair of glass substrates. The light source substrate is, for example, a substrate on which LEDs (Light Emitting Diodes) that illuminate the liquid crystal display element are mounted, and serves as a backlight for the liquid crystal display element. The light source substrate is disposed on the back side of the liquid crystal display element. The display means 4 also includes a member including a light guide plate, a reflector provided on the back side of the light guide plate, and a diffuser provided on the front side of the light guide plate in order to spread the light from the LEDs over the entire surface of the liquid crystal display element. The display means 4 is controlled by the circuit board 2 and is connected to the circuit board 2 by a flexible printed circuit board through an opening (not shown) provided in the frame 6.

[0042] The protective cover 5 is a translucent plate-like member (for example, inorganic glass, polycarbonate resin, or PMMA resin). The protective cover 5 is optically bonded to the front surface of the display means 4 with a translucent adhesive. The protective cover 5, together with the frame 6, covers the opening of the housing 1, thereby protecting the surface of the display means 4 from impacts and preventing dust and other particles from entering the housing 1 through the opening.

[0043] The frame 6 is attached to the opening of the housing 1 and holds the protective panel 5, the circuit board 2, and the display unit 4. As shown in FIG. 4 , the frame 6 and the housing 1 are joined at a joint 13a located at the tip of the peripheral wall 13 of the housing 1 and at a portion formed by the side portion 61, the frame-shaped support portion 62, and the hanging portion 63 of the frame 6. The frame 6 and the housing 1 are fixed together, for example, by screws. The protective panel 5 is bonded at its end on the frame 6 side to the frame-shaped support portion of the frame 6 by adhesive means, such as a known adhesive or adhesive sheet. The frame 6 holds the display unit 4 in the space surrounded by the frame-shaped upright wall portion 64 and back portion of the frame 6 and the protective panel 5. The frame 6 is connected to the display unit 4 by connecting means (not shown).

[0044] The present invention is not limited to the above-described embodiments and drawings, and modifications (including the omission of components) can be made as appropriate within the scope of the present invention.

[0045] In the above description, in order to facilitate understanding of the present invention, descriptions of well-known technical matters have been omitted as appropriate.

[0046] The present invention includes the following embodiments. [1] A housing having a heat sink section for accommodating heat-generating components therein, The heat sink portion is a plurality of fins protruding outward from the housing; a ventilation hole communicating between the inside and the outside of the housing; a protrusion that protrudes into the housing and is in thermal contact with the heat-generating component; a recessed portion recessed from the outside of the housing toward the tip of the protrusion; Equipped with At least a portion of one or more of the plurality of fins is provided in the hollowed portion, A housing in which the tips of one or more fins, at least a portion of which is provided in the cutout portion, protrude from the recesses in the cutout portion. [2] The housing of [1], wherein each of the plurality of fins is plate-shaped, and the plurality of fins are arranged so that the length direction of each of the plurality of fins is approximately vertical when in use. [3] The housing of [1] or [2], wherein, when in use, there is a gap formed between two adjacent fins of the plurality of fins above the ventilation hole. [4] The housing of any one of [1] to [3], wherein the ventilation hole is disposed in the center of the heat sink portion. [5] The housing according to any one of [1] to [4], wherein the heat-generating component is a circuit board. [6] The housing according to any one of [1] to [5], wherein the housing is an integrally molded product. [7] A device comprising the housing according to any one of [1] to [6] and the heat-generating component. [Explanation of symbols]

[0047] 1. Housing 11. Heat sink section 111,111a,111b···Fin 112 Ventilation hole 113···Convex part 114···First hollowed-out section 115···Second hollowed-out section 12 Connector connection opening 13...peripheral wall part 13a...Joining part 2. Circuit board 21. IC chip 3. Heat conduction material 4...Display means 5. Protective cover 6 Frames 61 Side 62...Frame support part 63... hanging part 64...Frame-shaped vertical wall 7···Connector

Claims

1. A housing having a heat sink section for accommodating heat-generating components therein, The heat sink portion is a plurality of fins protruding outward from the housing; a ventilation hole communicating between the inside and the outside of the housing; a protrusion that protrudes into the housing and is in thermal contact with the heat-generating component; a recessed portion recessed from the outside of the housing toward the tip of the protrusion; Equipped with At least a portion of one or more of the plurality of fins is provided in the hollowed portion, A housing, wherein a tip portion of one or more fins, at least a portion of which is provided in the lightening portion, protrudes from a recess in the lightening portion.

2. The housing according to claim 1 , wherein each of the plurality of fins is plate-shaped, and the plurality of fins are arranged such that a length direction of each of the plurality of fins is substantially vertical when in use.

3. The housing according to claim 2 , wherein a void is formed above the vent hole between two adjacent fins of the plurality of fins.

4. The housing according to claim 1 , wherein the vent hole is located in a central portion of the heat sink portion.

5. The housing of claim 1 , wherein the heat-generating component is a circuit board.

6. The housing of claim 1 , wherein the housing is a single piece.

7. A device comprising the housing according to any one of claims 1 to 6 and the heat-generating component.

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