JP2022042064A - Housing structure of electronic device - Google Patents

Abstract

To provide a housing structure for an electronic device achieving effective vibration countermeasures to suppress vibration from multiple directions.SOLUTION: A rack-mounted industrial computer housing 1 includes a front opening and houses a printed circuit board and the like. The housing 1 further includes a top plate 4, a bottom plate, a back plate 6, and left and right side plates 7. The inner peripheral edges of the corners 7a of the side plates 7 are connected by a metal frame 8. Further, the back plate 6 is not fixed to a frame 8 but to a female screw hole 7e of a mounting piece 7c formed in each side plate 7 by screwing.SELECTED DRAWING: Figure 8

Description

The present invention relates to a structure of a housing for accommodating electronic components of an electronic device.

For example, Patent Document 1 is known as a housing structure of an electronic device. The housing of Patent Document 1 is mainly composed of a box-shaped housing body.

The housing body is configured by joining the left and right side plates, the back plate, the bottom plate, and the top plate in a box shape so as to have a front opening. Further, a printed board (printed wiring board) is housed in the housing body from the front opening, and a substantially U-shaped front plate is attached to the front end of each printed board.

Japanese Patent Application Laid-Open No. 2003-152359

Electronic components such as a CPU and a hard disk drive device (hereinafter referred to as HDD) are mounted on each printed circuit board. The performance of these electronic components has improved remarkably, and the processing speed has been improving year by year.

However, while the processing speed is improved, the vulnerability of electronic devices to vibration is promoted. In particular, industrial computers are used in places where vibrations occur, such as factory production lines and vehicles, so vibrations may cause malfunctions.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an effective vibration countermeasure by suppressing vibration from a plurality of directions in a housing of an electronic device.

(1) The present invention is a structure of a housing for accommodating parts of an electronic device and having a front opening.
The housing has a pair of side plates and
A bottom plate that closes between the lower ends of both side plates and
A top plate that closes between the upper ends of the side plate and
A back plate that closes between the rear ends of the side plate and
A frame connecting the inner peripheral edges of each corner of the both side plates,
Equipped with
The back plate is characterized in that it is fixed to both side plates instead of the frame.

(2) In one aspect of fixing the back plate,
A mounting piece bent in a direction facing each other is formed at the rear end of each side plate, and the back plate is fixed to the mounting piece.

(3) In another aspect of fixing the back plate,
A pair of female screw holes are formed in each of the mounting pieces.
The back plate is fixed to the mounting piece by screwing it into the female screw hole of each mounting piece.

(4) One aspect of the component includes an electronic component mounted on a printed circuit board and a dedicated power supply, and the printed circuit board and the dedicated power supply are fixed to the frame.

According to the present invention, vibration from a plurality of directions is suppressed in the housing of the electronic device, so that effective vibration countermeasures can be taken.

(A) is a front perspective view showing a housing of an industrial computer according to an embodiment, (b) is the same rear perspective view, and (c) is the same lower rear perspective view. A front perspective view showing a housing structure in a state where the top plate and the bottom plate are omitted. A partial view showing a fixed state of the top plate and the bottom plate. Rear perspective view showing the left and right side plates. Front perspective view showing the state when vibrated in the vertical direction from the installation surface of the housing. Explanatory drawing which shows the bending vibration direction of a frame. The rear perspective view which shows the housing structure of the comparative example. The rear perspective view which shows the structure which fixes the back plate to the left and right side plates. A front perspective view showing a state when the vehicle is vibrated in the left-right direction from the installation surface of the housing. A rear perspective view showing the diagonal line of the housing. A rear perspective view showing a state when the vehicle is vibrated in the front-rear direction from the installation surface of the housing.

Hereinafter, the housing structure of the electronic device according to the embodiment of the present invention will be described. Here, as an example of the electronic device to which the present invention is applied, an example of an industrial computer installed in a production line of a factory or the like will be described.

As industrial computers, desktop type and rack mount type are mainly used. Since the desktop type industrial computer has relatively few restrictions on the installation location and few restrictions on the housing size, it is possible to provide a vibration damping structure outside the housing.

On the other hand, rack-mounted industrial computers have all the external dimensions of the housing determined by the standard, and often have the same structural design. Further, since the storage space of the rack is almost the same as the external dimensions of the housing of the industrial computer, it is difficult to provide a vibration damping structure outside the housing, and the storage space may not be provided with vibration countermeasures. many.

Therefore, in the structure of the embodiment, the vibration of the electronic components in the housing is reduced by improving the sheet metal constituting the housing of the rack-mounted industrial computer, and the vibration transmitted by amplification in the housing is suppressed. rice field.

The housing (case) 1 of the industrial computer according to the embodiment will be described with reference to FIGS. 1 to 11. The "up", "down", "front", "rear", "right", and "left" arrows shown in the figure are above, below, forward (front direction), and rear (rear) of the housing 1, respectively. Direction) ・ Indicates the right direction and the left direction.

<< Configuration of housing 1 >>
As shown in FIG. 1, the housing 1 is formed in a box shape having a front opening 2. Most of the electronic components housed in the housing 1, for example, a CPU, RAM, hard disk drive device (hereinafter referred to as HDD), etc., are mounted on each printed circuit board (printed circuit board) 3 shown in FIG. 1 (a). Has been done.

The printed board 3 is housed inside from the front opening 2 along a rail (not shown). Of the electronic components housed in the housing 1, the dedicated power supply (not shown) is housed in the housing 1 without using the printed circuit board 3.

Specifically, the housing 1 includes five metal plates (top plate 4, bottom plate 5, back plate 6, left and right side plates 7) and four metal frames 8 shown in FIGS. 2 and 3. It is mainly composed of and. At this time, as shown in FIGS. 1 (a) to 1 (c), the top plate 4 closes between the upper ends of the both side plates 7, the bottom plate 5 closes between the lower ends of the both side plates 7, and the back plate 6 closes between the lower ends. The space between the rear ends of both side plates 7 is closed. A pair of mounting holes 6a (see FIG. 1C) are formed through the both ends of the back plate 6.

Further, as shown in FIG. 2, a pair of the frames 8 are arranged in the left-right direction on the upper and lower sides between the side plates 4. That is, the inner peripheral edges of the corner portions 7a of the side surface plates 4 are connected by the frames 8, and both end portions of the frame 8 are fixed to the inner peripheral edges by screwing.

Here, as shown in FIG. 3, the top plate 4 is fixed to the upper surface of the two frames 8 arranged above by screwing, while the bottom plate is attached to the lower surface of the two frames 8 arranged below. 5 is fixed by screwing. The printed circuit board 3 and the dedicated power supply housed in the housing 1 are directly fixed to the frame 8 by screwing.

As shown in FIG. 4, the side plate 7 has a mounting piece 7b whose lower end is bent inward and a mounting piece 7c which is bent inward from the rear end side. That is, the right side plate 7 is formed with the mounting pieces 7b and 7c bent in the left direction, while the left side plate 7 is formed with the mounting pieces 7b and 7c bent in the right direction. The mounting pieces 7b and 7c of the above face each other.

Further, a pair of female screw holes 7d and 7e are formed through the mounting pieces 7b and 7c, respectively. The mounting piece 7b is fixed to the housing installation surface of the rack storage space (not shown) by screwing a male screw member such as a bolt into the female screw hole 7d. On the other hand, the female screw hole 7e of the mounting piece 7c communicates with the mounting hole 6a of the back plate 6 and is screwed to the female screw hole 7e via the mounting hole 6a so that both ends of the back plate 6 are fixed to the mounting piece 7c. ..

≪Vibration isolation effect≫
The anti-vibration effect of the housing 1 will be described with reference to FIGS. 5 to 11. Since it is expected that the housing 1 of the rack-mounted industrial computer will be subjected to vibrations in various directions in the vertical direction, the horizontal direction, and the front-rear direction from the above-mentioned housing installation surface, each direction will be described individually.

(1) Vertical Vibration First, a case where the vertical vibration shown by the arrow P1 in FIG. 5 is applied to the housing 1 from the housing installation surface will be described. Since this vibration P1 is an in-plane force (stress vector is in the plane of the XY coordinate system) for each side plate 7, it is hardly amplified in the side plate 7 (response magnification is "1"). Do not exceed.).

However, for the surface between the upper and lower frames 8, that is, the top plate 4 and the bottom plate 5, the vibration of the arrow P1 becomes an out-of-plane force (the stress vector is out of the plane of the XY coordinate system). Therefore, the surface vibration of the arrow P2 that amplifies the vibration transmitted from the housing installation surface is individually generated on the top plate 4 and the bottom plate 5. In particular, individual resonances of surface vibrations are likely to occur at frequencies close to each other when the top plate 4 and the bottom plate 5 have substantially the same structure and mass.

At this time, the surface vibration P2 of the top plate 4 develops into the bending vibration (arrow P3 in FIG. 6) of the two frames 8 arranged above. At the same time, the surface vibration P2 of the bottom plate 5 develops into the bending vibration P3 of the two frames 8 arranged below.

The housing 11 of the comparative example shown in FIG. 7 has a structure in which the back plate 6 is fixed to the upper and lower frames 8 arranged at the rear. In FIG. 7, 8a shows a female screw hole formed in the frame 8, and 6b shows a mounting hole communicating with the female screw hole 8a. Here, the back plate 6 is fixed to the upper and lower frames 8 by screwing to the female screw hole 8a via the mounting hole 6b.

In the case of the housing 11, although the vibration of the arrow P1 is an in-plane force of the side plate 7, the back plate 6 plays a role of transmitting individual bending vibrations to the upper and lower frames 8 to be fixed. Therefore, when the natural peripheral frequencies of the bending vibrations of the four frames 8 are close to each other, there is a possibility that the vibration accelerations of the four frames 8 are amplified.

Then, considering that the printed circuit board 3 in the housing 1 and the dedicated power supply are directly fixed to the four frames 8, there is a possibility that the bending vibration of each frame 8 is directly transmitted. In this case, if the bending vibration transmitted to the frame 8 can be suppressed to a small value, the adverse effects on the CPU, HDD, and the like mounted on the printed board 3 can be reduced.

Therefore, as shown in FIG. 8, the housing 1 adopts a structure in which the back plate 6 is fixed to the mounting pieces 7c formed on the left and right side plates 7 by screwing. According to this structure, the back plate 6 can be separated from the bending vibration of the upper and lower frames 8 arranged at the rear, and the amplification of the bending vibration can be prevented at this point. As an actual measurement value, the result of reducing the acceleration of the bending vibration by 50% was obtained, and the RW characteristic of the HDD mounted on the printed board 3 could be improved by 10 times or more.

(2) Vibration in the left-right direction Next, a case where the vibration in the left-right direction (lateral vibration) shown by the arrow P4 in FIG. 9 is applied to the housing 1 from the housing installation surface will be described. Since this vibration P4 is an out-of-plane force for the left and right side surface plates 7, surface vibration may occur in the side surface plates 7 on both sides, causing resonance.

At this time, since the lower end portion of the side plate 7 is close to the housing installation surface, the vibration P4 is hardly amplified. On the other hand, the upper end portion of the side plate 7 is far from the housing installation surface, and there is a possibility that the vibration P4 is greatly amplified.

As a result, the vibration P4 of the two frames 8 arranged above the four frame 8 groups is amplified, and the amplified vibration P4 passes through the respective frames 8 to the printed circuit board 3 in the housing 1 and the vibration P4. It may be transmitted to the dedicated power supply. This vibration P4 changes the lengths of the diagonal lines X1 and X2 (see FIG. 10) between the left and right side plates 7 and the four frames 8.

When the back plate 6 is screwed to the upper and lower frames 8 as in the housing 11 of the comparative example, the binding force for suppressing the vibration P4 that changes the lengths of the diagonal lines X1 and X2 of the housing 11 is strengthened. In other words, the rigidity of the housing 11 with respect to the vibration P4 becomes stronger. This vibration P4 becomes the largest in the resonance state.

Here, the vibration "u" received from the housing installation surface is expressed by the equation (1), "a = acceleration", "ω = angular acceleration", "t = time", and "M = mass of the housing". If "K = rigidity of the housing" and "c = viscosity of the housing" are set, the value of the acceleration "A" at the time of resonance of the housing can be calculated by the equation (2).

According to the equation (2), the smaller the rigidity of the housing, that is, the value of "K", the smaller the acceleration at resonance can be. Looking at the housing 1, as shown in FIG. 8, the vibration P4 that changes the lengths of the diagonal lines X1 and X2 is generated by screwing the back plate 6 to the mounting pieces 7c of the left and right side plate 7. The force to suppress, that is, the rigidity is reduced. Then, according to the configuration of the housing 1, the acceleration of the vibration P4 can be reduced as shown in the equation (2), and in this respect as well, the CPU and HDD mounted on the printed plate 3 can be reduced. It is possible to suppress adverse effects on such things. It was confirmed that the acceleration of the vibration P4 could actually be reduced by "5% to 10%", and the RW characteristics of the HDD mounted in the housing 1 could be improved by about 4 times.

(2) Anti-vibration against vibration in the front-rear direction Finally, a case where the vibration P5 in the front-rear direction shown in FIG. 11 is applied to the housing 1 from the housing installation surface will be described. This vibration P5 is transmitted to the top plate 4 and the bottom plate 5 via the left and right side plates 7.

At this time, since the vibration P5 is an in-plane force for the plates 4, 5 and 7, it is hardly amplified in the face plates of the plates 4, 5 and 7. However, since the vibration P5 exerts an out-of-plane force on the back plate 6, there is a risk of causing surface vibration in the surface of the back plate 6 and amplifying it.

When the back plate 6 is fixed to the upper and lower frames 8 arranged rearward by screwing as in the housing 1 of the comparative example, the surface vibration of the back plate 6 is directly transmitted to the upper and lower frames 8. Bending vibration occurs. Therefore, surface vibration may be transmitted to the printed circuit board 3 directly fixed to each frame 8 and the dedicated power supply via the upper and lower frames 8.

Therefore, in the housing 1, as shown in FIG. 8, the back plate 6 is fixed to the mounting pieces 7c of the left and right side plate 7 by screwing. According to this configuration, the surface vibration of the back plate 6 can be isolated from the upper and lower frames, and the vibration transmission to the printed plate 3 and the dedicated power supply due to the surface vibration can be suppressed. Actually, it was confirmed that the acceleration of the bending vibration was reduced by about "10% to 20%", and the RW performance of the HDD mounted in the housing 1 could be improved by about 4 times.

Therefore, according to the structure of the housing 1, the vibration of the printed plate 3 in the housing 1 and the vibration of the dedicated power supply generated by the vibration P1 in the vertical direction P1, the vibration P4 in the horizontal direction P4, and the vibration P5 in the front-rear direction is a simple structure. It can be effectively reduced. In this respect, it is possible to take effective vibration countermeasures for suppressing vibration from a plurality of directions to the housing 1 of the rack-mounted industrial computer.

The present invention is not limited to the above embodiment, and can be modified and implemented within the scope described in each claim. For example, the method of fixing the back plate 6 is not limited to screwing, and other means such as slide fitting to the mounting piece 7c may be adopted.

1 ... Housing 2 ... Front opening 3 ... Printed board 4 ... Top plate 5 ... Bottom plate 6 ... Back plate 7 ... Side plate 7a ... Corner parts 7b, 7c ... Mounting pieces 7d, 7e ... Female screw holes 8 ... Frame

Claims (4)

It is a housing structure that stores electronic device parts and has a front opening.
The housing has a pair of side plates and
A bottom plate that closes between the lower ends of both side plates and
A top plate that closes between the upper ends of the side plate and
A back plate that closes between the rear ends of the side plate and
A frame connecting the inner peripheral edges of each corner of the both side plates,
Equipped with
The housing structure of an electronic device, wherein the back plate is fixed to both side plates instead of the frame. At the rear end of each of the side plates, mounting pieces bent in directions facing each other are formed.
The housing structure for an electronic device according to claim 1, wherein the back plate is fixed to the mounting piece. A pair of female screw holes are formed in each of the mounting pieces.
The housing structure for an electronic device according to claim 2, wherein the back plate is fixed to the mounting piece by screwing it into the female screw hole of each mounting piece. The components include electronic components mounted on a printed circuit board and a dedicated power supply.
The housing structure for an electronic device according to any one of claims 1 to 3, wherein the printed circuit board and the dedicated power supply are fixed to the frame.

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