WO2021197173A1

WO2021197173A1 - Device housing, device, and laser radar

Info

Publication number: WO2021197173A1
Application number: PCT/CN2021/082819
Authority: WO
Inventors: 胡冲; 任民
Original assignee: 华为技术有限公司
Priority date: 2020-03-30
Filing date: 2021-03-24
Publication date: 2021-10-07
Also published as: CN113473762A; CN113473762B

Abstract

The present application relates to the technical field of housings. Disclosed are a device housing, a device, and a laser radar. The device housing comprises one or more foam metal composite walls. The one or more foam metal composite walls comprise at least an external connecting wall of the device housing, and the foam metal composite wall comprises a foam metal layer. The foam metal composite wall disclosed in the present application comprises a foam metal layer, therefore, the device housing has vibration isolation, sound absorption and heat dissipation functions due to good vibration isolation, sound absorption and heat dissipation properties of the foam metal layer, and in combination with a design of a metal rigid wall and a metal mesh surface protection layer, the vibration isolation, sound absorption and heat dissipation effects of a structure can be improved, especially the sound absorbing capability can be extended to medium and low frequencies. The application of the device housing to a device can achieve the effective protection for components and devices inside the device.

Description

Equipment housing, equipment and lidar

This application claims the priority of a Chinese patent application filed on March 30, 2020 with the application number 202010237980.2 and the invention title "Equipment Shell, Equipment and Lidar", the entire content of which is incorporated into this application by reference.

Technical field

This application relates to the technical field of housings, in particular to a device housing, a device and a lidar.

Background technique

As the degree of automation increases, various electronic devices are often installed on vehicles. For example, in order to realize the automatic driving of a vehicle, it is necessary to install a lidar on the vehicle to detect the surrounding environment.

During the driving of the vehicle, due to the complex environment that the vehicle passes through, it is inevitable that vibration will occur. Therefore, various components inside the electronic equipment may be affected by external vibration and noise, resulting in performance degradation or even damage. In addition, the heat generated by the internal components of the electronic equipment also needs to be dissipated in time through the equipment housing.

Therefore, this requires at least the equipment housing of the electronic equipment to have the functions of vibration isolation, sound absorption and heat dissipation, so as to effectively protect the internal components of the electronic equipment.

Summary of the invention

The embodiments of the present application provide a device housing, a device, and a lidar, which can solve technical problems existing in related technologies. The technical solutions of the equipment housing, equipment and lidar may be as follows:

In a first aspect, a device housing is provided, which includes one or more foamed metal composite walls, wherein the one or more foamed metal composite walls include at least the external connecting wall of the equipment housing, and the foamed metal composite wall includes foam Metal layer.

Wherein, the device housing provided in the embodiment of the present application may be a vehicle-mounted device housing. For example, it can be a MEMS lidar housing, but it is not limited to this. When the device housing is a Micro Electro Mechanical System (MEMS) lidar housing, the device housing also includes a transparent window for light to pass through, and the transparent window may be a glass window. The equipment shell may be a rectangular parallelepiped shell, including six shell walls, the external connecting walls of the six shell walls are foam metal composite walls, the six shell walls also include a transparent window, and the remaining four shell walls may be foam The metal composite wall may also be an existing ordinary shell wall (for example, it may be a single-layer metal plate), which is not limited in this application.

The external connection wall of the equipment housing can be understood as the installation wall of the equipment housing, and the external connection wall is connected to the installation surface. For example, the external connection wall of the equipment housing can be connected to the vehicle body.

The foamed metal composite wall includes a foamed metal layer, the foamed metal layer includes a foamed metal, and may also include a metal frame for fixing the foamed metal, and the metal frame provides support for the entire foamed metal. The material of the foamed metal layer can be foamed copper or foamed aluminum, but is not limited thereto. The foamed metal layer has the characteristics of high heat dissipation coefficient and high damping characteristics (for example, the damping value of foamed aluminum is about 5-10 times that of ordinary aluminum), and its vibration isolation, heat dissipation and sound absorption functions are good. The size of the foamed metal layer can be set according to actual needs.

The solution shown in the embodiment of the present application at least makes the external connection wall of the equipment casing a foamed metal composite wall, so that the heat dissipation, vibration isolation and sound absorption functions of the equipment casing are better. The specific principle is as follows:

First, in terms of heat dissipation: the metal foam layer has a higher heat dissipation coefficient. When the metal foam layer is placed in a flowing fluid (such as air), due to the high specific area of the metal foam layer and complex three-dimensional flow, convection can be improved. Heat dissipation, so that the equipment shell has a strong heat dissipation capacity.

Second, in terms of vibration isolation: the foamed metal layer has high damping characteristics. When the foamed metal layer vibrates, it will be forced to contract and consume more energy, so that excessive vibration can be effectively attenuated.

Thirdly, in terms of sound absorption: sound waves are incident on the metal foam layer to excite the air in the pores of the metal foam layer to vibrate, causing relative movement between the air and the solid ribs. Due to the viscosity of air, corresponding internal friction and viscous resistance are generated in the pores, so that sound is converted into heat dissipation through vibration. It should be noted that the foamed metal layer has a better sound absorption effect on medium and high frequency sounds.

In a possible implementation manner, the thickness of the foamed metal layer is greater than 5 mm, the pore density of the foamed metal layer is 5PPI-40PPI, and the porosity of the foamed metal layer is greater than 70%. The aperture is 0.5mm～2mm.

In a possible implementation manner, the material of the foamed metal layer is foamed copper or foamed aluminum.

In a possible implementation manner, the foamed metal composite wall further includes a metal rigid wall layer, and the metal rigid wall layer is arranged on a side of the foamed metal layer close to the inside of the device;

The metal rigid wall layer includes a flat metal plate and a plurality of heat dissipation fins arranged on the flat metal plate, and the plurality of heat dissipation fins are in contact with the foamed metal layer.

The material of the metal rigid wall layer may be copper or aluminum, or other metal materials, which is not limited in this application.

The metal rigid wall layer can be integrally formed, or radiating fins can be welded on a flat metal plate.

In the solution shown in the embodiment of the present application, one side of the flat metal plate of the metal rigid wall layer can directly contact the heat source (various heat-generating components) inside the equipment housing, and the other side can be connected with multiple heat dissipation fins. The heat generated by the heat source can be transferred to a plurality of heat dissipation fins through the flat metal plate, and then transferred to the foam metal layer through the plurality of heat dissipation fins, and is dissipated by the foam metal layer.

By providing a metal rigid wall layer, the inside of the device can be sealed to prevent external particles from entering the inside of the device shell along the pores of the foamed metal layer, which plays a role of physical dust and moisture prevention.

In a possible implementation manner, a Helmholtz resonant cavity is formed between the planar metal plate, a plurality of heat dissipation fins and the foamed metal layer.

Among them, the Helmholtz resonator can also be called a Helmholtz resonator, which has a sound absorption function. The Helmholtz resonance cavity is composed of the back cavity and the neck, and the back cavity and the neck are connected. A flat metal plate, a plurality of heat dissipation fins and a foamed metal layer form a back cavity, and the pores on the foamed metal layer form a neck. The shape of the back cavity may be a cubic shape or a hemispherical shape, which is not limited in this application.

The Helmholtz resonant cavity has a better sound absorption effect for sounds with frequencies near the resonance frequency. The resonance frequency of the Helmholtz resonant cavity can be calculated according to the following formula:

f ₀ is the resonance frequency of the Helmholtz cavity; с is the speed of sound; s is the cross-sectional area of the neck opening; d is the diameter of the neck opening; l is the length of the neck; V is the volume of the back cavity.

Therefore, the specific dimensions of the Helmholtz resonant cavity formed between the planar metal plate, multiple heat dissipation fins, and the foamed metal layer can be determined according to specific sound absorption requirements.

The solution shown in the embodiment of the present application can extend the sound absorption capability of the device housing to the absorption of mid-, low- and high-frequency sound by forming a Helmholtz resonance cavity between the flat metal plate, the heat dissipation fin and the foamed metal layer.

In addition, the high-speed airflow impinging in all directions in the Helmholtz cavity increases the vibration of the air, increases the loss of sound wave intensity, and further enhances the sound absorption effect.

In a possible implementation manner, the plurality of heat dissipation fins includes a plurality of horizontal fins and a plurality of vertical fins.

In the solution shown in the embodiment of the present application, the horizontal fins and the vertical fins may be perpendicular to each other, and the number of the horizontal fins and the vertical fins may be set according to actual needs. There can be five fins, including two horizontal fins and three vertical fins. The five heat dissipation fins and the flat metal plate form two back cavities, and together with the foam metal layer form two Helmholtz resonant cavities.

The size of the flat metal plate and the heat dissipation fins can be set according to the actual sound absorption requirements, heat dissipation requirements, and the actual environment in which the equipment is located, which is not limited in this application.

In a possible implementation, the thickness of the flat metal plate is greater than 2 mm, the thickness of the heat dissipation fin is greater than 2 mm, the distance between any two horizontal fins is greater than 40 mm, and the thickness of any two vertical fins is greater than 40 mm. The distance therebetween is greater than 40 mm, and the size of the plurality of heat dissipation fins along a direction perpendicular to the plane metal plate is greater than 20 mm. The resonant frequency of the Helmholtz resonant cavity formed by the metal rigid wall layer of this size can reach about 2kHz.

In a possible implementation manner, the material of the metal rigid wall layer is copper or aluminum.

In a possible implementation manner, the foam metal composite wall further includes a metal mesh protective surface layer, and the metal mesh protective surface layer is arranged on a side of the foam metal layer away from the inside of the device.

Among them, the metal mesh protective surface layer can be a stainless steel screen. The aperture of the metal mesh protective surface layer can be set to be smaller, but it is not limited to this. The surface of the metal mesh protective layer can be treated with corrosion resistance to enhance the corrosion resistance of the metal mesh protective layer. For example, electrostatic spraying treatment can be carried out.

In the solution shown in the embodiment of the application, the metal mesh protective layer is provided on the outer side of the foam metal layer. The metal mesh protective layer can prevent dust particles and other impurities from entering the foam metal layer, which has a dust-proof function. The metal layer plays a protective role. Moreover, the metal mesh protective surface layer has holes to enhance convective heat dissipation.

In a possible implementation manner, the metal mesh protective surface layer is grounded.

In the solution shown in the embodiment of the present application, in order to achieve the effect of shielding the static electricity provided inside the equipment casing, the metal mesh protective surface layer may be grounded. In this way, due to electrostatic induction, induced charges will be generated on the outer surface of the metal mesh protective surface layer, and the induced charges will be released through grounding. Moreover, when the foamed metal composite wall further includes a metal rigid wall layer, a secondary shield can also be formed by the metal rigid wall layer and the metal walls of the remaining shell walls.

In a possible implementation manner, the mesh number of the metal mesh protective surface layer is greater than 100 meshes.

In a possible implementation manner, the material of the metal mesh protective surface layer is stainless steel.

In a possible implementation manner, the device housing further includes a transparent window.

For the solution shown in the embodiment of the present application, for example, when the equipment housing is a lidar equipment housing, the equipment housing needs to include a transparent window for the laser to pass through.

In a possible implementation manner, the equipment housing is a rectangular parallelepiped housing, the equipment housing includes a foamed metal composite wall and a transparent window, and the foamed metal composite wall is an external connection wall of the equipment housing.

In the solution shown in the embodiment of the present application, the device shell may be a rectangular parallelepiped shell, that is, the device shell has a total of six shell walls. Among the six shell walls, only the external connecting wall may be a foam metal composite wall, another shell wall may be a transparent window, and the other four shell walls may be ordinary shell walls, such as a single-layer metal shell wall. In this way, the heat dissipation, vibration isolation and sound absorption effects of the equipment housing are better, and the volume of the equipment housing will not be too large.

In a possible implementation manner, the equipment housing is a rectangular parallelepiped housing, and the equipment housing includes five foam metal composite walls and a transparent window.

In the solution shown in the embodiment of the present application, the device shell may be a rectangular parallelepiped shell, that is, the device shell has a total of six shell walls. The six equipment housings can include a transparent window and five foam metal composite walls, so that the equipment housing has the best heat dissipation, vibration isolation and sound absorption effects.

Which shell walls of the specific equipment housing are set as the foamed metal composite wall 1 can be selected according to the volume requirements of the equipment housing, and the requirements of heat dissipation, vibration isolation, and sound absorption effects of the equipment housing.

In a possible implementation manner, the device housing is applied to lidar.

In the solution shown in the embodiment of the present application, the device casing may be a lidar casing, and the lidar may be a MEMS lidar or a mechanical lidar.

In a possible implementation manner, the foamed metal composite wall includes a metal rigid wall layer, a foamed metal layer and a metal mesh protective surface layer in order from the inside to the outside.

Among them, the flat metal plate of the metal rigid wall layer can directly contact the heat source inside the device. After the equipment including the equipment shell is installed, the metal mesh protective surface of the equipment shell can be grounded.

The metal rigid wall layer, the foamed metal layer and the metal mesh protective surface layer can be connected by brazing and riveting processes, but are not limited to this.

The device housing provided by the embodiments of the present application has at least the following beneficial effects:

First, in terms of heat dissipation: the metal foam layer of the metal foam layer has a higher heat dissipation coefficient. When the metal foam layer that receives heat is placed in a flowing fluid, it can be greatly improved due to its large specific surface area and complex three-dimensional flow. Convection heat exchange, so that it has a high heat dissipation capacity.

Second, in terms of vibration isolation: the foamed metal layer has high damping characteristics. For example, the damping value of foamed aluminum is about 5-10 times that of pure aluminum. When the foamed metal layer is used as a damping layer, it will be forced to expand and contract and lose With more energy, the damping characteristics will effectively dampen excess vibration.

Third, in terms of sound absorption: sound waves incident on the foamed metal layer excite the air vibration in the micropores, causing relative movement between the air and the solid ribs. Due to the viscosity of the air, corresponding internal friction and friction are generated in the micropores. The viscous resistance causes sound to be dissipated by converting it into heat through vibration. This feature can effectively absorb mid- and high-frequency sound. In addition, in order to improve the sound absorption effect of mid- and low-frequency sounds, a Helmholtz resonance cavity is formed between the foamed metal layer and the metal rigid wall layer. Moreover, in the Helmholtz resonant cavity, the high-speed airflow impinging from all directions increases the vibration of the air, increases the loss of sound wave intensity, and further enhances the sound absorption effect.

Fourth, the aspect of electrostatic shielding: due to electrostatic induction, induced charges will be generated on the outer surface of the metal mesh protective surface layer, which will be released by grounding, and then a secondary shield will be formed by the enclosed rigid metal wall layer.

Fifth, dust and moisture resistance: the inner metal rigid wall layer is a closed structure, which can achieve physical dust and moisture resistance. The outermost metal mesh protection layer has a small pore size to prevent common dust particles from entering the holes of the foam metal layer.

In a second aspect, a device is provided, which includes the device housing according to any one of the first aspects.

Wherein, the device may be a vehicle-mounted device, specifically, it may be a lidar, and the lidar may be a mechanical lidar or a MEMS lidar, which is not limited in this application.

In the solution shown in the embodiment of the present application, the device housing of the device adopts the device housing provided in the embodiment of the present application, so that the components inside the device can be effectively protected.

In a third aspect, a lidar is provided, and the lidar includes the device housing according to any one of the above-mentioned first aspects.

Wherein, the lidar may be a MEMS lidar or a mechanical lidar, which is not limited in this application.

According to the solutions shown in the embodiments of the application, the lidar provided by the embodiments of the application may be a MEMS lidar. The MEMS lidar includes a device housing, and a laser assembly, a detector assembly, a MEMS galvanometer assembly, and a laser assembly arranged inside the equipment housing. Optical path system composed of lenses. The equipment housing includes a transparent window, and the external connection wall of the equipment housing is a foamed metal composite wall (the wall opposite to the transparent window), and the foamed metal composite wall is grounded.

The laser light emitted by the laser component of the lidar is transmitted to the MEMS galvanometer assembly through the optical path system, and then is reflected by the MEMS galvanometer assembly, and then emitted through the transparent window.

The reflected laser light is reflected by the MEMS galvanometer component to the optical path system, and then reflected to the detector component through the optical path system, and the reflected laser light is received by the detector component.

The beneficial effects brought about by the technical solutions provided by the embodiments of the present application are:

The embodiment of the present application provides a device housing. The external connecting wall of the device housing is a foamed metal composite wall. The foamed metal composite wall includes a foamed metal layer, and the foamed metal layer has good vibration isolation, sound absorption, and heat dissipation characteristics. This allows the equipment shell to achieve the functions of vibration isolation, sound absorption and heat dissipation. Therefore, when the equipment shell is applied to the equipment, it can effectively protect the internal components of the equipment.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a schematic diagram of a MEMS lidar provided by an embodiment of the present application;

Fig. 2 is a schematic diagram of a foamed metal layer provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of a metal rigid wall layer provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of a Helmholtz resonant cavity provided by an embodiment of the present application;

5 is a schematic diagram of a metal mesh protective surface layer provided by an embodiment of the present application;

Fig. 6 is a schematic diagram of a foamed metal composite wall provided by an embodiment of the present application.

illustration

1. Foamed metal composite wall, 11, foamed metal layer, 12, metal rigid wall layer, 121, flat metal plate, 122 heat dissipation fins, 1221, horizontal fins, 1222, vertical fins, 13, metal mesh protective surface Layer, 110, neck, 120, back cavity;

2. Transparent window;

3. Laser components;

4. Detector components;

5. MEMS galvanometer components;

6. Optical system.

Detailed ways

The embodiment of the present application provides a device housing, which can be applied to an in-vehicle device, for example, can be applied to a Micro Electro Mechanical System (MEMS) lidar. Of course, the device housing provided in the embodiments of this application can also be applied to other electronic devices, which is not limited in this application. In the following, the application of the device housing in the MEMS lidar will be described as an example.

MEMS lidar, as a next-generation mass-produced lidar, has the advantages of high resolution and low cost. As shown in Figure 1, the hardware system of the MEMS lidar includes a laser component 3, a detector component 4, a MEMS galvanometer component 5, and an optical path system 6 composed of an optical lens. These components are placed together in the equipment housing of the MEMS lidar. middle. Among them, the performance of the laser assembly 3 and the detector assembly 4 will deteriorate at high temperatures, and the vibration of the MEMS galvanometer assembly 5 is susceptible to external vibrations and external mid- and low-frequency (<3KHz) sounds. Due to the complexity of the working environment of MEMS lidar, in order to ensure the high performance and continuous and stable operation of components, at least strong heat dissipation, vibration isolation and sound absorption requirements are put forward for the equipment shell of MEMS lidar.

In the related art, in order to reduce the interference of vibration, the reliability of the long-term operation of the MEMS galvanometer assembly 5 is improved. Some MEMS lidars add vibration isolators on the bottom surface, or attach damping pads/sound-absorbing anti-vibration sheets on the surface to reduce vibration and noise interference, but this undoubtedly adds to the cost, and the externally attached materials are not good for the heat dissipation of the device.

The embodiment of the present application provides an equipment housing, as shown in Figure 1, Figure 2 and Figure 6, the equipment housing includes one or more foam metal composite walls 1, wherein the one or more foam metal composite walls 1 At least including the external connecting wall of the equipment shell, the foamed metal composite wall 1 includes a foamed metal layer 11.

Wherein, the device housing provided in the embodiment of the present application may be a vehicle-mounted device housing. For example, it can be a MEMS lidar housing, but it is not limited to this. When the equipment housing is a MEMS lidar housing, the equipment housing also includes a transparent window 2 for light to pass through, and the transparent window 2 may be a glass window. As shown in Figure 1, the equipment housing can be a rectangular parallelepiped housing, including six housing walls, the external connecting walls of the six housing walls are the foam metal composite wall 1, the six housing walls also include a transparent window 2, and the rest The four shell walls of may be the foam metal composite wall 1, or the existing ordinary shell walls (for example, may be a single-layer metal plate), which is not limited in this application.

The foamed metal composite wall 1 includes a foamed metal layer 11, which includes a foamed metal, and may also include a metal frame for fixing the foamed metal, and the metal frame provides support for the entire foamed metal. The material of the foamed metal layer 11 can be foamed copper or foamed aluminum, but is not limited thereto. The foamed metal layer 11 has the characteristics of high heat dissipation coefficient and high damping characteristics (for example, the damping value of foamed aluminum is about 5-10 times that of ordinary aluminum), and its vibration isolation, heat dissipation and sound absorption functions are good. The size of the metal foam layer 11 can be set according to actual needs. For example, the thickness of the metal foam layer 11 can be greater than 5mm, the pore density can be 5PPI-40PPI, the porosity can be greater than 70%, and the pore size can be 0.5mm-2mm.

In the solution shown in the embodiment of the present application, by making at least the external connecting wall of the equipment casing as the foamed metal composite wall 1, the heat dissipation, vibration isolation and sound absorption functions of the equipment casing are better. The specific principle is as follows:

First, in terms of heat dissipation: the heat dissipation coefficient of the foamed metal layer 11 is relatively high. When the foamed metal layer 11 is placed in a flowing fluid (such as air), because the foamed metal layer 11 has a high specific area and will produce a complex three-dimensional flow, It can improve the convection heat dissipation, so that the equipment shell has a strong heat dissipation capacity.

Second, in terms of vibration isolation: the foamed metal layer 11 has high damping characteristics. When the foamed metal layer 11 vibrates, it will be forced to contract and consume more energy, so that excessive vibration can be effectively attenuated.

Third, in terms of sound absorption: sound waves are incident on the metal foam layer 11 to excite the air in the pores of the metal foam layer 11 to vibrate, causing relative movement between the air and the solid ribs. Due to the viscosity of air, corresponding internal friction and viscous resistance are generated in the pores, so that sound is converted into heat dissipation through vibration. It should be noted that the foamed metal layer 11 has a better sound absorption effect on medium and high frequency sounds.

In addition to the metal foam layer 11, the metal foam composite wall 1 may also include a metal rigid wall layer 12. By adding a metal rigid wall layer 12, the heat dissipation capacity of the equipment housing can be improved, and the sound absorption capacity of the equipment housing can be improved, and the medium and high frequency sound absorption of the foam metal composite wall 1 can be extended to low, medium and high frequency sound absorption. The specific scheme can be described as follows :

In a possible implementation manner, as shown in FIGS. 3 and 6, the foamed metal composite wall 1 further includes a metal rigid wall layer 12, and the metal rigid wall layer 12 is arranged on the side of the foamed metal layer 11 close to the inside of the device. The metal rigid wall layer 12 includes a flat metal plate 121 and a plurality of heat dissipation fins 122 arranged on the flat metal plate 121, and the plurality of heat dissipation fins 122 are in contact with the foamed metal layer 11.

The material of the metal rigid wall layer 12 may be copper or aluminum, or other metal materials, which is not limited in this application.

The metal rigid wall layer 12 can be integrally formed, or the heat dissipation fins 122 can be welded to the flat metal plate 121.

In the solution shown in the embodiment of the present application, one side of the flat metal plate 121 of the metal rigid wall layer 12 can directly contact the heat source (various heat-generating components) inside the equipment housing, and the other side can be connected with multiple heat dissipation fins. 122. The heat generated by the heat source can be transferred to the plurality of heat dissipation fins 122 through the flat metal plate 121, and then transferred to the foam metal layer 121 through the plurality of heat dissipation fins 122, and is radiated by the foam metal layer 121.

By providing the metal rigid wall layer 12, the inside of the device can be sealed, and external particles can be prevented from entering the inside of the device shell along the pores of the foamed metal layer 11, which plays a role of physical dust-proof and moisture-proof.

In a possible implementation manner, a Helmholtz resonant cavity is formed between the planar metal plate 121, the plurality of heat dissipation fins 122, and the foam metal layer 11.

Among them, the Helmholtz resonator can also be called a Helmholtz resonator, which has a sound absorption function. As shown in FIG. 4, the Helmholtz resonance cavity is composed of a back cavity 120 and a neck 110, and the back cavity 120 and the neck 110 communicate with each other. The flat metal plate 121, the plurality of heat dissipation fins 122 and the foamed metal layer 11 form the back cavity 120, and the pores on the foamed metal layer 11 constitute the neck 110. The shape of the back cavity 120 may be a cube shape or a hemispherical shape, which is not limited in this application.

Therefore, the specific size of the Helmholtz resonant cavity formed between the planar metal plate 121, the plurality of heat dissipation fins 122 and the foamed metal layer 11 can be determined according to specific sound absorption requirements.

The solution shown in the embodiment of the present application can extend the sound absorption capability of the device housing to medium, low, and high frequency sounds by forming a Helmholtz resonance cavity between the flat metal plate 121, the heat dissipation fin 122, and the foam metal layer 11. Absorption.

In a possible implementation, as shown in FIG. 3, the plurality of heat dissipation fins 122 include a plurality of horizontal fins 1221 and a plurality of vertical fins 1222.

Wherein, the horizontal fins 1221 and the vertical fins 1222 may be perpendicular to each other, and the number of the horizontal fins 1221 and the vertical fins 1222 may be set according to actual needs. As shown in FIG. 3, there may be five heat dissipation fins 122, including two horizontal fins 1221 and three vertical fins 1222. The five heat dissipation fins 122 and the flat metal plate 121 form two back cavities, and together with the foam metal layer 11 form two Helmholtz resonant cavities.

The size of the flat metal plate 121 and the heat dissipation fin 122 can be set according to the actual sound absorption requirements, heat dissipation requirements, and the actual environment in which the device is located, which is not limited in this application.

For example, the thickness of the planar metal plate 121 is greater than 2 mm, the thickness of the plurality of heat dissipation fins 122 is greater than 2 mm, the distance between any two vertical fins 1222 is greater than 40 mm, and the distance between any two horizontal fins 1221 is greater than 40 mm , The size of the plurality of heat dissipation fins 122 along the direction perpendicular to the plane metal plate 121 is greater than 20 mm. The resonant frequency of the Helmholtz resonant cavity formed by the metal rigid wall layer 12 of this size can reach about 2 kHz.

The foamed metal composite wall 1 may also include a metal mesh protective surface layer 13, so as to protect the foamed metal layer 11 and achieve the effect of electrostatic shielding. This is very important for components that need to use magnetoelectric or electrostatic drive. . The specific scheme can be described as follows:

In a possible implementation, as shown in Figures 5 and 6, the foamed metal composite wall 1 further includes a metal mesh protective surface layer 13, which is arranged on the side of the foamed metal layer 11 away from the inside of the device. .

Wherein, the metal mesh protective layer 13 may be a stainless steel screen. The aperture of the metal mesh protective layer 13 can be set smaller. For example, the mesh of the metal mesh protective layer 13 can be greater than 100 meshes, but is not limited to this. The surface of the metal mesh protective layer 13 can be treated with corrosion resistance to enhance the corrosion resistance of the metal mesh protective layer 13. For example, electrostatic spraying treatment can be carried out.

In the solution shown in the embodiment of the present application, by providing a metal mesh protective layer 13 on the outside of the foam metal layer 11, the metal mesh protective layer 13 can prevent dust particles and other impurities from entering the foam metal layer 11, thereby preventing dust Function to protect the foamed metal layer 11. Moreover, the metal mesh protective surface layer 13 has holes to enhance convective heat dissipation.

In addition, in order to achieve the effect of shielding the static electricity provided inside the equipment casing, the metal mesh protective surface layer 13 may be grounded. In this way, due to the electrostatic induction effect, induced charges will be generated on the outer surface of the metal mesh protective surface layer 13, and the induced charges will be released through grounding. Moreover, when the foamed metal composite wall 1 further includes a metal rigid wall layer 12, a secondary shield can also be formed by the metal rigid wall layer 12 and the metal walls of the remaining shell walls.

It should be noted that the metal foam composite wall 1 in the equipment housing provided by the embodiments of the present application may only include the foam metal layer 11, or may only include the foam metal layer 11 and the metal rigid wall layer 12, or may only include the foam metal layer. 11 and the metal mesh protective surface layer 13 may also include a foamed metal layer 11, a metal rigid wall layer 12 and a metal mesh protective surface layer 13, which are not limited in this application.

It should also be noted that, in the device housing provided by the embodiments of the present application, only the external connecting wall may be a foamed metal composite wall 1, or all shell walls of the device housing (except those with special requirements, for example, , The transparent windows) are all foam metal composite walls 1, and some specific shell walls of the equipment housing can also be foam metal composite walls 1, which are not limited in the embodiment of the present application. When all the shell walls of the equipment shell are foam metal composite walls 1, the heat dissipation, vibration isolation and sound absorption effects of the equipment shell are the best, but the volume of the equipment shell will become larger. When only the external connecting wall of the equipment housing is the foamed metal composite wall 1, the volume of the equipment housing is small, but the effect of heat dissipation, vibration isolation and sound absorption of the equipment housing may be worse. Therefore, which shell walls of the specific equipment housing are set as the foam metal composite wall 1 can be selected according to the volume requirements of the equipment housing, and the requirements of the heat dissipation, vibration isolation and sound absorption effects of the equipment housing.

Hereinafter, taking the foamed metal composite wall 1 including the foamed metal layer 11, the metal rigid wall layer 12 and the metal mesh protective surface layer 13 as an example, the equipment enclosure provided by the embodiment of the present application will be described in detail:

As shown in FIG. 6, the foamed metal composite wall 1 of the equipment housing provided by the embodiment of the present application includes a rigid metal wall layer 12, a foamed metal layer 11 and a metal mesh protective surface layer 13 in order from the inside to the outside. The flat metal plate 121 of the metal rigid wall layer 12 can directly contact the heat source inside the device, and the metal mesh protective surface layer 13 can be grounded. The metal rigid wall layer 12, the foamed metal layer 11 and the metal mesh protective surface layer 13 may be connected by brazing and riveting processes, but are not limited to this.

The foamed metal layer 11 provided by the embodiments of the present application may be through-hole foamed aluminum or through-hole foamed copper, with a thickness greater than 10mm, a pore density less than 20PPI, a porosity greater than 85%, and a pore size of 0.8-2mm to ensure heat dissipation and sound absorption reduction. Vibrating balance.

The metal rigid wall layer 12 is made of aluminum or copper, where the thickness of the flat metal plate 121 is greater than 2mm; the thickness of the heat dissipation fins 122 is greater than 2mm, and the width is greater than 20mm; the spacing between the heat dissipation fins 122 is greater than 40mm; The resonant frequency of the Helmholtz resonator formed between the metal rigid wall layer 12 and the foamed metal layer 11 can reach about 2 kHz.

The metal mesh protective surface layer 13 is made of stainless steel wire mesh, the mesh number is required to be more than 100 meshes, and the surface is electrostatically sprayed to improve corrosion resistance and grounding.

First, in terms of heat dissipation: the metal foam layer 11 has a higher heat dissipation coefficient. When the metal foam layer 11 that receives heat is placed in a flowing fluid, it has a large specific surface area and produces a complex three-dimensional flow. Significantly improve the convection heat transfer, so that it has a high heat dissipation capacity.

Second, in terms of vibration isolation: the foamed metal layer 11 has high damping characteristics. For example, the damping value of the foamed aluminum is about 5-10 times that of pure aluminum, and the foamed metal layer 11 will be forced to expand and contract when it is used as a damping layer. , More energy is lost, and the damping characteristic will effectively dampen excessive vibration.

Third, in terms of sound absorption: sound waves incident into the foamed metal layer 11 excite the air in the micropores to vibrate, causing relative movement between the air and the solid ribs. Due to the viscosity of the air, corresponding internal friction is generated in the micropores. With viscous resistance, sound is converted into heat through vibration and dissipated. This feature can effectively absorb mid- to high-frequency sound. In addition, in order to improve the sound absorption effect of mid- and low-frequency sounds, a Helmholtz resonance cavity is formed between the foamed metal layer 11 and the metal rigid wall layer 12. Moreover, in the Helmholtz resonant cavity, the high-speed airflow impinging from all directions increases the vibration of the air, increases the loss of sound wave intensity, and further enhances the sound absorption effect.

Fourth, electrostatic shielding: due to electrostatic induction, induced charges will be generated on the outer surface of the metal mesh protective surface layer 13, which will be released by grounding, and then the enclosed rigid metal wall layer 12 will form a secondary shield.

Fifth, in terms of dust and moisture resistance: the inner metal rigid wall layer 12 is a closed structure, which can achieve physical dust and moisture resistance. The outermost metal mesh protective layer 13 has a small pore size, which can prevent common dust particles from entering the foam metal layer 11 Holes.

An embodiment of the present application also provides a device, which includes the device housing described in any one of the foregoing.

An embodiment of the present application also provides a laser radar. As shown in FIG. 1, the laser radar includes any of the above-mentioned equipment housings.

The solution shown in the embodiment of the application is shown in FIG. 1. The laser radar provided by the embodiment of the application may be a MEMS laser radar. The MEMS laser radar includes a device housing, and a laser component 3 and a detector component arranged inside the device housing 4. MEMS galvanometer assembly 5 and optical path system 6 composed of lenses. The equipment housing includes a transparent window 2, and the external connecting wall of the equipment housing is a foamed metal composite wall 1 (the wall opposite to the transparent window 2), and the foamed metal composite wall 1 is grounded.

The laser light emitted by the laser component 3 of the lidar provided by the embodiment of the present application is transmitted to the MEMS galvanometer assembly 5 through the optical path system 6, and then is reflected by the MEMS galvanometer assembly 5, and then emitted through the transparent window 2.

The reflected laser light is reflected by the MEMS galvanometer assembly 5 to the optical path system 6, and then reflected by the optical path system 6 to the detector assembly 4, and the reflected laser light is received by the detector assembly 4.

The above is only an embodiment of the application and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the principles of the application shall be included in the protection scope of the application.

Claims

An equipment housing, characterized in that the equipment housing includes one or more foamed metal composite walls (1), wherein the one or more foamed metal composite walls (1) at least include the exterior of the equipment housing The connecting wall, the foamed metal composite wall (1) includes a foamed metal layer (11).
The device enclosure according to claim 1, wherein the thickness of the foamed metal layer (11) is greater than 5mm, the pore density of the foamed metal layer (11) is 5PPI-40PPI, and the foamed metal layer (11) The porosity of) is greater than 70%, and the pore size of the foamed metal layer (11) is 0.5mm-2mm.
The device housing according to any one of claims 1 or 2, wherein the material of the foamed metal layer (11) is foamed copper or foamed aluminum.
The device enclosure according to claim 1, wherein the foamed metal composite wall (1) further comprises a metal rigid wall layer (12), and the metal rigid wall layer (12) is arranged on the foam metal layer ( 11) The side close to the inside of the equipment;

The metal rigid wall layer (12) includes a flat metal plate (121) and a plurality of heat dissipation fins (122) arranged on the flat metal plate (121), and the plurality of heat dissipation fins (122) are connected to the The foamed metal layer (11) is in contact.
The device housing according to claim 4, characterized in that Helmholtz resonance is formed between the flat metal plate (121), the plurality of heat dissipation fins (122) and the foamed metal layer (11) Cavity.
The device enclosure according to claim 5, wherein the plurality of heat dissipation fins (122) comprise a plurality of horizontal fins (1221) and a plurality of vertical fins (1222).
The device enclosure according to claim 6, wherein the thickness of the flat metal plate (121) is greater than 2mm, the thickness of the heat dissipation fin (122) is greater than 2mm, and any two horizontal fins (1221) The distance between the two vertical fins (1222) is greater than 40mm, the distance between any two vertical fins (1222) is greater than 40mm, and the size of the heat dissipation fins (122) along the direction perpendicular to the plane metal plate (121) is greater than 20mm.
The device housing according to any one of claims 4-7, wherein the material of the metal rigid wall layer (12) is copper or aluminum.
The equipment housing according to any one of claims 1-2 or 4-7, wherein the foamed metal composite wall (1) further comprises a metal mesh protective surface layer (13), and the metal mesh protective surface layer (13) It is arranged on the side of the foamed metal layer (11) away from the inside of the device.
The device housing according to claim 9, characterized in that the metal mesh protective surface layer (13) is grounded.
The equipment housing according to claim 9, characterized in that the mesh number of the metal mesh protective surface layer (13) is greater than 100 meshes.
The equipment housing according to claim 9, characterized in that the material of the metal mesh protective surface layer (13) is stainless steel.
The device casing according to claim 1, wherein the device casing further comprises a transparent window (2).
The equipment housing according to claim 13, characterized in that the equipment housing is a rectangular parallelepiped housing, the equipment housing includes a foamed metal composite wall (1) and a transparent window (2), and the foamed metal composite wall ( 1) It is the external connecting wall of the equipment housing.
The equipment housing according to claim 13, wherein the equipment housing is a rectangular parallelepiped housing, and the equipment housing includes five foam metal composite walls (1) and a transparent window (2).
The device housing of claim 1, wherein the device housing is used in a lidar.
A device, characterized in that the device comprises the device housing according to any one of claims 1-16.
A laser radar, characterized in that the laser radar comprises the equipment housing according to any one of claims 1-16.