Electronic equipment device

Abstract

To enable circuit boards different in size to be accommodated in a common case while improving vibration resistance.SOLUTION: An electronic equipment device 11 includes a circuit board 12, a case 16, a first cover 23, a second cover 26, and a fixture 29. The circuit board 12 has insertion holes 13, 14 (fixing parts) for being housed in the case 16 via the fixture 29. The case 16 has: a frame-shaped inner wall 17 with an upper surface 16A and a lower surface 16B open; and a frame 21 joined to the inner wall 17 and extending in the planar direction of the circuit board 12. A plurality of frames 21 are arranged inside the case 16 with a predetermined gap therebetween. The fixture 29 is inserted into the gap between the frames 21 and fixed.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an electronic device apparatus including a case for housing a circuit board.

Background Art

[0002] Construction machines represented by excavators are equipped with electronic device apparatuses for controlling the vehicle body. A wide variety of types of electronic device apparatuses have been developed for each application of the construction machines to be mounted. In addition to this, in recent years, along with further increases in added value and high performance of electronic components, version upgrades such as miniaturization of electronic device apparatuses and component changes have been frequently carried out. The dimensions of the circuit board inside the thus-designed electronic device apparatus and the case for housing the circuit board vary depending on the type and specifications of the construction machine. However, construction machines are basically produced in small quantities and with a wide variety of types. For this reason, the increase in electronic device apparatuses with different shapes and the like as described above has caused an increase in cost in terms of design and manufacturing. Therefore, reduction of cost by commonalization of components such as cases is required.

[0003] Techniques for solving the above problems related to electronic device apparatuses are disclosed in Patent Document 1. According to the technique described in Patent Document 1, by connecting a connector and a substrate with a flexible printed wiring board and providing substrate support portions in a plurality of locations inside the case, circuit boards with different dimensions can be fixed to a common case.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the configuration disclosed in Patent Document 1, circuit boards with different dimensions can be fixed by providing substrate support portions at multiple locations. However, since the fixing locations are limited to the end portions on the outer side of the circuit board, the inner portion of the circuit board cannot be fixed. Since construction machinery is used in an environment with intense vibration, in the case of a large circuit board, in order to improve vibration resistance, not only the outer portion but also the inner portion of the circuit board needs to be fixed to the case.

[0006] An object of the present invention is to provide an electronic device that can accommodate circuit boards with different dimensions in a common case and also takes vibration resistance into consideration.

Means for Solving the Problems

[0007] The present invention includes a circuit board, a case for accommodating the circuit board, a first cover for covering the upper side of the case, a second cover for covering the lower side of the case, and a fixture for fixing the circuit board to the case. In the electronic device in which the circuit board has a fixing portion for being accommodated in the case via the fixture, the case has a frame-shaped inner wall with an open upper surface and a lower surface, and a frame joined to the inner wall and extending in the plane direction of the circuit board. A plurality of the frames are arranged inside the case with a predetermined gap, and the fixture is inserted and fixed into the gap between the frames.

Effects of the Invention

[0008] According to the present invention, circuit boards with different dimensions can be accommodated in a common case, and vibration resistance can be enhanced.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Mode for Carrying Out the Invention

[0010] Hereinafter, an electronic device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking the case of applying it to a hydraulic excavator as an example.

[0011] As shown in Fig. 1, the hydraulic excavator 1 includes a crawler-type lower traveling body 2 that can travel in the front-rear direction, an upper revolving body 3 that is rotatably mounted on the lower traveling body 2, and a working device 4 provided on the front side of the upper revolving body 3. The lower traveling body 2 and the upper revolving body 3 constitute the main body (vehicle body) of the hydraulic excavator 1. The hydraulic excavator 1 travels to the work site by the lower traveling body 2, and performs earth excavation work and the like using the working device 4 while revolving the upper revolving body 3.

[0012] The upper revolving body 3 has a revolving frame 5 as a vehicle body frame. The revolving frame 5 constitutes the base of the upper revolving body 3 and is rotatably mounted on the lower traveling body 2. A counterweight 6, a building cover 7, and a cab 8 are provided on the revolving frame 5.

[0013] The counterweight 6 is provided at the rear part of the revolving frame 5. This counterweight 6 is a heavy object that balances the weight with the working device 4.

[0014] The building cover 7 is located in front of the counterweight 6 and is provided on the revolving frame 5. A machine room is formed inside the building cover 7. Mounted equipment (not shown) such as an engine and a hydraulic pump is accommodated in the machine room inside the building cover 7.

[0015] The cab 8 is provided on the left front side of the slewing frame 5. The cab 8 defines a driver's cab in which an operator rides. As shown in FIG. 2, inside the cab 8, for example, a driver's seat 9 on which the operator sits, a travel operation lever, and a work operation lever (both not shown) are arranged. Further, an electronic device unit 11 is disposed inside the cab 8. The electronic device unit 11 is located, for example, below the driver's seat 9 and fixed to the floor surface of the cab 8. The present invention is not limited thereto. For example, as shown by the dashed line in FIG. 2, the electronic device unit 11 may be located behind the driver's seat 9 and fixed to the inner wall (rear wall surface) of the cab 8. Further, the electronic device unit 11 is not limited to the inside of the cab 8 (driver's cab), and may be arranged, for example, inside the building cover 7 (machine room). Furthermore, the electronic device unit 11 is not limited to the upper slewing body 3, and may be arranged on the lower traveling body 2.

[0016] Next, the configuration of the electronic device unit 11 according to the first embodiment will be described with reference to FIGS. 3 to 10.

[0017] As shown in FIGS. 3 to 5, the electronic device unit 11 includes a circuit board 12, a case 16 that houses the circuit board 12, a first cover 23 that covers the upper side of the case 16, a second cover 26 that covers the lower side of the case 16, and a fixture 29 for fixing the circuit board 12 to the case 16.

[0018] As shown in FIG. 5, the circuit board 12 is formed, for example, in a rectangular plate shape. Various electronic components (not shown) are attached to the upper surface (first main surface) and the lower surface (second main surface) of the circuit board 12. Thereby, a control circuit for controlling various electrical devices such as an air conditioner, a communication device, a display device, an audio device, and a lighting device is formed on the circuit board 12. Note that the control circuit may control hydraulic devices such as control valves, or may control an inverter.

[0019] The circuit board 12 is formed with a plurality of insertion holes 13 and 14 as fixing portions. The insertion hole 13 is disposed at an end portion 12A that is an outer portion of the circuit board 12. For this reason, the plurality (for example, six) of insertion holes 13 are located at the rear side in the front-rear direction and both end sides in the left-right direction of the circuit board 12, and are arranged along the outer peripheral edge of the circuit board 12. On the other hand, the insertion hole 14 is disposed at a central portion 12B that is an inner portion of the circuit board 12. The plurality (for example, two) of insertion holes 14 are located at an intermediate portion in the front-rear direction of the circuit board 12 and are arranged at an intermediate portion in the left-right direction.

[0020] A connector 15 is attached to the front side of the circuit board 12. The connector 15 is located, for example, at the front end of the circuit board 12 and is attached to the lower surface of the circuit board 12. The connector 15 includes a connector case 15A, terminal pins 15B, and connection terminals 15C. The connector case 15A is formed, for example, in a rectangular bottomed cylindrical shape with an open front end portion. A plurality of terminal pins 15B are arranged inside the connector case 15A and extend forward from the bottom (rear inner portion) of the connector case 15A. The terminal pins 15B are electrically connected to an external electrical device when the connector 15 is connected to an external connector (not shown). One end side of the connection terminal 15C is connected to the terminal pin 15B. The other end side of the connection terminal 15C is joined to the circuit board 12 by, for example, soldering. Thereby, the terminal pins 15B and the connection terminals 15C electrically connect between the external electrical device and the control circuit of the circuit board 12.

[0021] As shown in FIGS. 5 to 7, the case 16 has an inner wall 17 in a frame shape with an open upper surface 16A (first main surface) and a lower surface 16B (first main surface), and a frame 21 joined to the inner wall 17 and extending in the plane direction of the circuit board 12. The inner wall 17 is formed, for example, in a rectangular frame shape. The case 16 is formed, for example, in a rectangular box shape using a metal material, a resin material, or the like.

[0022] At this time, the inner wall 17 has a front wall portion 17A and a rear wall portion 17B disposed at both ends in the front-rear direction, and a left wall portion 17C and a right wall portion 17D disposed at both ends in the left-right direction. The left wall portion 17C is disposed at the left ends of the front wall portion 17A and the rear wall portion 17B and connects them. The right wall portion 17D is disposed at the right ends of the front wall portion 17A and the rear wall portion 17B and connects them. At the corner portions (four corner portions) of the inner wall 17, screw holes 17E are formed at positions on the upper surface 16A, and screw holes 17F are formed at positions on the lower surface 16B. The screw holes 17E and 17F maintain the assembled state of the first cover 23 and the second cover 26 with the case 16. Further, inside the inner wall 17, a substrate support portion 18 that supports the circuit board 12 is provided at a position below the inner wall 17. The substrate support portion 57 is formed in a planar shape with a gap and has a horizontally placed ladder shape (lattice shape).

[0023] On the front side in the front-rear direction of the inner wall 17, a connector fitting portion 19 into which the connector 15 is fitted is formed. The connector fitting portion 19 is located, for example, at the intermediate portion in the left-right direction of the front wall portion 17A and is formed by partially cutting out the upper side of the front wall portion 17A. For this reason, the connector fitting portion 19 has a rectangular shape along the outer shape of the connector case 15A. Thereby, when the electronic device 11 is assembled, the connector 15 is inserted from above, facilitating the positioning of the circuit board 12.

[0024] The frame 21 is joined to the inner wall 17 and extends in the planar direction of the circuit board 12. The frame 21 extends linearly, for example, in the front-rear direction of the case 16. A plurality of frames 21 are provided inside the case 16. These plurality of frames 21 are arranged at equal intervals in the left-right direction of the case 16. At this time, the frames 21 are arranged in plurality inside the case 16 with slits 22 having a predetermined gap. Thereby, the plurality of frames 21 are arranged in a substantially planar shape and form the substrate support portion 18 that becomes the bottom surface portion of the case 16.

[0025] The slit 22 is located between two adjacent frames 21 and extends in the front-rear direction with a predetermined width dimension. The slit 22 is an elongated gap that penetrates the frames 21 in the vertical direction and extends along the frames 21. The width dimension of the slit 22 is set to a value such that, for example, the shaft portion of the bolt 30 can be inserted, while the head of the bolt 30 cannot be inserted. Also, the width dimension of the slit 22 is set to a value smaller than the outer diameter dimension of the cylindrical spacer 32.

[0026] In addition, in FIGS. 5 to 7, the frames 21 are illustrated as having the same width dimension and thickness dimension, but the present invention is not limited to this. If a required number (for example, two or more) of slits 22 can be formed, the shapes of the frames 21, including the width dimension of the frames 21, may be different from each other.

[0027] As shown in FIG. 5, the first cover 23 covers the upper side of the case 16. The first cover 23 is formed, for example, in a rectangular shape with the same outer shape as the case 16. Insertion holes 24 penetrating in the thickness direction are formed at the corner portions (four corner portions) of the first cover 23. The bolt 25 is inserted through the insertion hole 24 of the first cover 23, and its tip portion is screwed into the screw hole 17E of the case 16. Thereby, the first cover 23 is fixed to the upper side of the case 16, closing the upper opening portion of the case 16.

[0028] As shown in FIG. 5, the second cover 26 covers the lower side of the case 16. The second cover 26 is formed, for example, in a rectangular shape with the same outer shape as the case 16. Insertion holes 27 penetrating in the thickness direction are formed at the corner portions (four corner portions) of the second cover 26. The bolt 28 is inserted through the insertion hole 27 of the second cover 26, and its tip portion is screwed into the screw hole 17F of the case 16. Thereby, the second cover 26 is fixed to the lower side of the case 16, closing the lower opening portion of the case 16.

[0029] The fixture 29 fixes the circuit board 12 to the case 16. As shown in FIGS. 5, 8 to 10, the fixture 29 is constituted by, for example, a bolt 30 and a nut 31. The bolt 30 is inserted through the insertion hole 13 of the circuit board 12 and, via the spacer 32, is inserted into the slit 22. Also, the bolt 30 is inserted through the insertion hole 14 of the circuit board 12 and, via the spacer 32, is inserted into the slit 22.

[0030] At this time, the spacer 32 is formed in a cylindrical shape (circular cylindrical shape) extending in the vertical direction and is inserted between the lower surface of the circuit board 12 and the upper surface of the frame 21. A nut 31 disposed on the lower surface of the frame 21 is screwed onto the tip of the bolt 30. Thereby, the circuit board 12 is positioned inside the inner wall 17 and is attached to the case 16 in a state substantially parallel to the plurality of frames 21.

[0031] The electronic device 11 according to the present embodiment has the configuration as described above. Next, the assembly procedure of the electronic device 11 will be described with reference to FIGS. 3, 4, 5, 8 to 12.

[0032] As shown in FIGS. 8 to 10, the circuit board 12 is disposed inside the case 16. At this time, the connector 15 is inserted into the connector fitting portion 19 of the case 16. Thereby, at the time of assembly, the circuit board 12 can be easily positioned with respect to the case 16. In this state, the bolt 30 is inserted into the insertion hole 13 of the circuit board 12 and the bolt 30 is inserted into the insertion hole 14 (see FIGS. 5 and 10). At this time, the shaft portion of the bolt 30 is inserted through the insertion hole 13 of the circuit board 12 and, via the spacer 32, is inserted into the slit 22. Similarly, the shaft portion of the bolt 30 is inserted through the insertion hole 14 of the circuit board 12 and, via the spacer 32, is inserted into the slit 22. A nut 31 is screwed onto the tip of the shaft portion of the bolt 30 from the lower surface side of the frame 21. Thereby, the circuit board 12 is fixed inside the case 16.

[0033] Figs. 11 and 12 show a case where a circuit board 41 having a size different from that of the circuit board 12 is housed inside the case 16. Specifically described, the circuit board 41 is formed, for example, in a rectangular plate shape similar to the circuit board 12. A connector 15 is attached to the front side of the circuit board 41.

[0034] However, the circuit board 41 is smaller than the circuit board 12. That is, the length dimension in the front - rear direction of the circuit board 41 is set to a value smaller than the length dimension in the front - rear direction of the circuit board 12. In addition to this, the length dimension in the left - right direction of the circuit board 41 is set to a value smaller than the length dimension in the left - right direction of the circuit board 12.

[0035] A plurality of insertion holes 42 as fixing portions are formed in the circuit board 41. The insertion holes 42 are arranged at an end portion 41A which is an outer portion of the circuit board 41. For this reason, a plurality (for example, five) of insertion holes 42 are located at the rear side in the front - rear direction and both end sides in the left - right direction of the circuit board 41, and are arranged in a U - shape along the outer peripheral edge of the circuit board 41. On the other hand, no insertion holes as fixing portions are formed in a central portion 41B which is an inner portion of the circuit board 41. In this respect, the circuit board 41 is different from the circuit board 12. The reason for this is that since the circuit board 41 is smaller than the circuit board 12, by fixing the end portion 41A, vibration etc. of the central portion 41B can be suppressed.

[0036] When attaching the circuit board 41 to the case 16, the connector 15 is inserted into the connector fitting portion 19 of the case 16, and the circuit board 41 is positioned with respect to the case 16. In this state, bolts 30 are inserted into the insertion holes 42 of the circuit board 41. At this time, the shaft portion of the bolt 30 is inserted through the insertion hole 13 of the circuit board 12 and is inserted through the slit 22 via the spacer 32. A nut 31 is screwed to the tip of the shaft portion of the bolt 30 from the lower surface side of the frame 21. Thereby, the circuit board 41 is fixed inside the case 16. Note that even for the small circuit board 41, it may have a through - hole for inserting the bolt 30 in the central portion 41B. In this case, the vibration suppression effect of the circuit board 41 becomes larger.

[0037] As shown in FIGS. 8 to 10, the circuit board 12 is designed such that the same bolt 30 can be inserted into the insertion holes 13 and 14 and the slit 22. Also, as shown in FIGS. 11 and 12, for a circuit board 41 different from the circuit board 12, the same bolt 30 can be inserted into the insertion hole 42 thereof. Therefore, the case 16 can accommodate circuit boards 41 of different dimensions.

[0038] Also, the large circuit board 12 can be fixed not only at the end portion 12A but also at the central portion 12B by the fixture 29. Therefore, breakage of the circuit board 12 due to vibration can be prevented. At this time, a spacer 32 is interposed between the circuit board 12 and the frame 21 constituting the board support portion 18. As a result, a gap corresponding to the height dimension of the spacer 32 is formed between the circuit board 12 and the board support portion 18. Therefore, not only on the upper surface of the circuit board 12 but also on the lower surface of the circuit board 12 facing the board support portion 18, electronic components such as capacitors can be mounted. As a result, the degree of freedom in the design of the circuit board 12 can be improved.

[0039] Next, with the first cover 23 in contact with the upper surface 16A of the case 16, the shaft portion of the bolt 25 is inserted into the insertion hole 24 and screwed into the screw hole 17E of the case 16 (see FIGS. 3 to 5). Thereby, the first cover 23 is fixed to the upper surface 16A of the case 16.

[0040] Similarly, with the second cover 26 in contact with the lower surface 16B of the case 16, the shaft portion of the bolt 28 is inserted into the insertion hole 27 and screwed into the screw hole 17F of the case 16. Thereby, the second cover 26 is fixed to the lower surface 16B of the case 16. As a result, with the circuit board 12 accommodated therein, the case 16 has its upper opening closed by the first cover 23 and its lower opening closed by the second cover 26, and the electronic device 11 is completed.

[0041] Thus, the electronic device 11 of the present embodiment includes a circuit board 12, a case 16 that houses the circuit board 12, a first cover 23 that covers the upper side of the case 16, a second cover 26 that covers the lower side of the case 16, and a fixture 29 for fixing the circuit board 12 to the case 16. The circuit board 12 has insertion holes 13 and 14 as fixing portions for being housed in the case 16 via the fixture 29. At this time, the case 16 has a frame-shaped inner wall 17 with an open upper surface 16A and a lower surface 16B, and a frame 21 joined to the inner wall 17 and extending in the plane direction of the circuit board 12. A plurality of frames 21 are arranged inside the case 16 with a predetermined gap (slit 22), and the fixture 29 is inserted and fixed into the slit 22 that becomes a gap between the frames 21.

[0042] Therefore, the fixture 29 can be attached at any position of the slit 22 extending in the front-rear direction of the case 16. Also, a plurality of frames 21 are arranged in the left-right direction of the case 16. As a result, a plurality of slits 22 are also arranged in the left-right direction of the case 16. For this reason, the fixture 29 can be attached to any of the plurality of slits 22 arranged side by side in the left-right direction. Therefore, the common case 16 can house circuit boards 12 and 41 of different dimensions and fix the circuit boards 12 and 41 to the case 16. In this way, by making the case 16 common, the design cost and management cost can be reduced.

[0043] Also, the fixing portions (insertion holes 13 and 14) of the circuit board 12 are arranged at the outer portion (end portion 12A) and the inner portion (central portion 12B) of the circuit board 12. For this reason, the circuit board 12 can be fixed not only by the end portion 12A but also by the central portion 12B with the fixture 29. Therefore, even when the case 16 vibrates as the hydraulic excavator 1 is driven, with the end portion 12A of the circuit board 12 fixed, the central portion 12B is displaced together with the board support portion 18 of the case 16. For this reason, for example, the central portion 12B of the circuit board 12 does not repeatedly approach and separate from the board support portion 18, and vibrations of such a central portion 12B and deformation of the circuit board 12 can be suppressed. Thereby, breakage of the circuit board 12 due to vibration can be prevented.

[0044] The circuit board 12 has a connector 15. At this time, the slit 22 extends in the insertion direction of the connector 15. Therefore, when fixing the circuit board 12 to the case 16, the position of the circuit board 12 can be adjusted with respect to the insertion direction of the connector 15.

[0045] In the first embodiment, the position of the connector 15 is set as the long side portion (for example, the front side portion) of the circuit board 12. The present invention is not limited to this, and for example, the position of the connector 15 may be set as the short side portion (for example, the left side portion) of the circuit board 20. At this time, the slit 22 preferably extends in the insertion direction of the connector 15. Therefore, when the position of the connector 15 is set as the short side portion (for example, the left side portion) of the circuit board 20, the slit preferably extends in the left - right direction.

[0046] In the first embodiment, the case where the fixture 29 is composed of a bolt 30 and a nut 31 is illustrated, but the present invention is not limited to this. The fixture may be, for example, a rivet or a tapping screw. That is, the fixture may have a structure capable of fixing the circuit boards 12 and 41 to the case 16.

[0047] Next, with reference to FIGS. 13 to 16, a second embodiment of the present invention will be described. The feature of the second embodiment is that the frame has a structure extending radially in the plane direction of the circuit board. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0048] As shown in FIG. 13, the electronic device 51 according to the second embodiment includes a circuit board 52, a case 55 that houses the circuit board 52, a first cover 61 that covers the upper side of the case 55, a second cover 64 that covers the lower side of the case 55, and a fixture 29 for fixing the circuit board 52 to the case 55.

[0049] The circuit board 52 is formed, for example, in a rectangular plate shape. As shown in FIG. 14, various electronic components (not shown) are attached to the upper surface (first main surface) and the lower surface (second main surface) of the circuit board 52. Thus, a control circuit for controlling various electrical devices is formed on the circuit board 52 in the same manner as the circuit board 12 according to the first embodiment.

[0050] A plurality of insertion holes 53 as fixing portions are formed in the circuit board 52. The insertion holes 53 are arranged at the end portion 52A which is the outer portion of the circuit board 52. For this reason, a plurality (for example, eight) of insertion holes 53 are respectively located on both end sides in the front-rear direction and both end sides in the left-right direction of the circuit board 52, and are arranged in a state of surrounding the outer peripheral edge portion of the circuit board 52.

[0051] A connector 54 is attached to the central portion 52B which is the inner portion of the circuit board 52. The connector 54 is located, for example, at the central portion 52B of the circuit board 52 and is attached to the upper surface of the circuit board 52. The connector 54 includes a connector case 54A, terminal pins 54B, and connection terminals (not shown). The connector case 54A is formed, for example, in a square bottomed cylindrical shape with an open upper end portion. A plurality of terminal pins 54B are arranged inside the connector case 54A and extend upward from the bottom (lower back portion) of the connector case 54A. The terminal pins 54B are electrically connected to an external electrical device when the connector 54 is connected to an external connector (not shown). The connection terminals extend in the same vertical direction as the terminal pins 54B and continuously extend linearly. The connection terminals project downward from the lower surface of the circuit board 12. One end side of the connection terminal is connected to the terminal pin 54B. The other end side of the connection terminal projects downward from the lower surface of the circuit board 52 and is joined to the circuit board 52 by, for example, soldering.

[0052] The case 55 has a frame-shaped inner wall 56 with an open upper surface 55A (first main surface) and a lower surface 55B (second main surface), and a frame 59 joined to the inner wall 56 and extending in the planar direction of the circuit board 52. As shown in FIGS. 13 and 15, the inner wall 56 is formed, for example, in a rectangular frame shape. The case 55 is formed, for example, in a rectangular box shape using a metal material, a resin material, or the like.

[0053] At this time, the inner wall 56 has a front wall portion 56A and a rear wall portion 56B arranged at both ends in the front-rear direction, and a left wall portion 56C and a right wall portion 56D arranged at both ends in the left-right direction. The left wall portion 56C is arranged at the left ends of the front wall portion 56A and the rear wall portion 56B and connects them. The right wall portion 56D is arranged at the right ends of the front wall portion 56A and the rear wall portion 56B and connects them. At the corner portions (four corner portions) of the inner wall 56, screw holes 56E are formed at positions on the upper surface 55A, and screw holes 56F are formed at positions on the lower surface 55B. Inside the inner wall 56, a board support portion 57 for supporting the circuit board 52 is provided at an intermediate portion in the vertical direction of the inner wall 56.

[0054] The board support portion 57 is formed in a planar shape with a gap. At the central portion of the board support portion 57, a connector fitting portion 58 into which the connector 54 is fitted is formed. The connector fitting portion 58 is formed, for example, by a through hole that penetrates the board support portion 57 in the vertical direction. The connector fitting portion 58 has a rectangular shape, for example, according to the outer shape of the connector case 54A. When the circuit board 52 is placed on the upper surface of the board support portion 57 of the case 55 during the assembly of the electronic device 51, the connection terminals of the connector 54 are inserted into the connector fitting portion 58. Thereby, the connector fitting portion 58 prevents the connection terminals of the connector 54 from interfering with the board support portion 57.

[0055] The frame 59 is joined to the inner wall 56 and extends in the planar direction of the circuit board 52. The frame 59 extends radially, for example, from the central portion (connector fitting portion 58) of the case 55 toward the outer peripheral edge portion. A plurality of frames 59 are provided inside the case 55. The frames 59 are paired in twos. For example, eight pairs of frames 59 are provided inside the case 55. Among these, four pairs of frames 59 extend respectively from the connector fitting portion 58 toward the four corners of the case 55. The remaining four pairs of frames 59 extend respectively from the connector fitting portion 58 in the front-back direction and left-right direction of the case 55. These multiple frames 59 are arranged in a substantially planar shape and form the board support portion 57 that becomes the bottom surface portion of the case 55.

[0056] A slit 60 having a predetermined width dimension is formed between a pair of frames 59. The slit 60 penetrates in the vertical direction of the frame 59 and is an elongated gap extending along the pair of frames 59. The width dimension of the slit 60 is set to a value such that, for example, the shaft portion of the bolt 30 can be inserted and the head of the bolt 30 cannot be inserted.

[0057] In addition, in FIG. 15, the case where all the frames 59 have the same width dimension and thickness dimension is illustrated, but the present invention is not limited to this. As long as a necessary number (for example, two or more) of slits 60 can be formed, the shape of the frame 59 including the width dimension etc. of the frame 59 may be different from each other.

[0058] The first cover 61 covers the upper side of the case 55. As shown in FIGS. 13 and 16, the first cover 61 is formed in a square shape, for example, with the same outer shape as the case 55. An opening 62 through which the connector 54 can be inserted is formed at a position corresponding to the connector 54 in the central portion of the first cover 61. The opening 62 is a through hole penetrating in the vertical direction (thickness direction) of the first cover 61 and is formed in a square shape, for example, similar to the connector 54.

[0059] At the corner portions (four corner portions) of the first cover 61, insertion holes 24 penetrating in the thickness direction are formed. The bolt 25 is inserted through the insertion hole 24 of the first cover 61, and its tip portion is screwed into the screw hole 56E of the case 55. Thereby, the first cover 61 is fixed above the case 55 and closes the upper opening portion of the case 55.

[0060] The second cover 63 covers the lower side of the case 55. As shown in FIG. 13, the second cover 63 is formed in a rectangular shape, for example, with the same outer shape as the case 55. At the corner portions (four corner portions) of the second cover 63, insertion holes 27 penetrating in the thickness direction are formed. The bolt 28 is inserted through the insertion hole 27 of the second cover 63, and its tip portion is screwed into the screw hole 56F of the case 55. Thereby, the second cover 63 is fixed below the case 55 and closes the lower opening portion of the case 55.

[0061] The fixture 29 fixes the circuit board 52 to the case 55. The fixture 29 is constituted by, for example, a bolt 30 and a nut 31. The bolt 30 is inserted through the insertion hole 53 of the circuit board 52 and is inserted through the slit 60 via the spacer 32. At this time, the spacer 32 is formed in a cylindrical shape (circular cylindrical shape) extending in the vertical direction and is inserted between the lower surface of the circuit board 52 and the upper surface of the frame 59. The nut 31 is screwed onto the tip of the bolt 30 from the lower surface side of the frame 59. Thereby, the circuit board 52 is located inside the inner wall 56 and is attached to the case 55 in a state substantially parallel to the plurality of frames 59.

[0062] The electronic device 51 according to the present embodiment has the configuration as described above. Next, the assembly procedure of the electronic device 51 will be described with reference to FIG. 13.

[0063] First, place the circuit board 52 inside the case 55. At this time, after placing the circuit board 52 above the board support portion 57, insert the connection terminals of the connector 54 into the connector fitting portion 58 of the case 55. In this state, insert the bolt 30 into the insertion hole 53 of the circuit board 52. At this time, the shaft portion of the bolt 30 is inserted through the insertion hole 53 of the circuit board 52 and, via the spacer 32, is inserted into the slit 60. A nut 31 is screwed onto the tip of the shaft portion of the bolt 30. Thereby, the circuit board 52 is fixed inside the case 55.

[0064] Next, with the first cover 61 in contact with the upper surface 55A of the case 55, fix the first cover 61 to the upper surface 55A of the case 55 using the bolt 25. Similarly, with the second cover 63 in contact with the lower surface 55B of the case 55, fix the second cover 26 to the lower surface 55B of the case 55 using the bolt 28. As a result, with the circuit board 52 housed inside it, the case 55 has its upper opening closed by the first cover 61 and its lower opening closed by the second cover 63, and the electronic device 51 is completed.

[0065] Thus, also in the second embodiment configured in this way, substantially the same operational effects as those of the first embodiment can be obtained. In the second embodiment, the frame 59 has a structure that extends radially in the plane direction of the circuit board 52. At this time, the slit 60 extends radially along the frame 59. For this reason, the fixture 29 can be attached at any position of the slit 60 that extends radially inside the case 55. Therefore, the common case 55 can accommodate circuit boards 52 of different dimensions.

[0066] In the second embodiment, a connector 54 is provided at the central portion 52B of the circuit board 52. The lower portion of the connector 54 is fitted into the connector fitting portion 58, and the upper portion of the connector 54 is inserted into the insertion hole 24 of the first cover 61. Therefore, the central portion 52B of the circuit board 52 is positioned and fixed through the connector 54, and its vibration is suppressed. For this reason, also in the second embodiment, it has the same vibration resistance as the first embodiment. In addition to this, in the second embodiment, the size of the circuit board 52 can be designed steplessly with the dimension of the inner wall 56 of the case 55 as the upper limit, and the degree of freedom in designing the circuit board 52 can be improved.

[0067] In the second embodiment, the connector 54 is provided above the circuit board 52, and an opening 62 for exposing the connector 54 to the outside is provided in the first cover 61 that covers the upper side of the case 55. However, the present invention is not limited to this. For example, the connector 54 may be provided below the circuit board 52, and an opening for exposing the connector 54 to the outside may be provided in the second cover 26 that covers the lower side of the case 55.

[0068] In the second embodiment, the through hole 53 as a fixing portion is provided only at the end portion 52A of the circuit board 52. However, the present invention is not limited to this. Not limited to the end portion 52A of the circuit board 52, the central portion 52B of the circuit board 52 may also have a through hole for inserting the bolt 30. In this case, the vibration suppression effect of the circuit board 52 is increased.

[0069] Next, a third embodiment of the present invention will be described with reference to FIGS. 17 and 18. The feature of the third embodiment is that the cases are joined to each other in a state where a plurality of them are stacked in the vertical direction. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0070] The electronic device 71 according to the third embodiment includes a circuit board 12, cases 16 and 72 that house the circuit board 12, a first cover 23 that covers the upper side of the case 72, a second cover 26 that covers the lower side of the case 16, and a fixture 29 for fixing the circuit board 12 to the cases 16 and 72.

[0071] The case 72 is formed substantially the same as the case 16. Therefore, the case 72 has a frame-shaped inner wall 17 with an open upper surface 72A (first main surface) and a lower surface 72B (first main surface), and a frame 21 joined to the inner wall 17 and extending in the planar direction of the circuit board 12. The case 72 is formed in a rectangular box shape using, for example, a metal material, a resin material, or the like. Inside the inner wall 17, a flat substrate support portion 18 that supports the circuit board 12 and is located below the inner wall 17 is provided. The substrate support portion 18 is composed of a plurality of frames 21. A slit 22 is formed between two adjacent frames 21. On the front side in the front-rear direction of the inner wall 17, a connector fitting portion 19 into which the connector 15 is fitted is formed. The circuit board 12 is attached inside the case 72 using the fixture 29.

[0072] However, insertion holes 73 penetrating in the vertical direction are formed at the corner portions (four corner portions) of the inner wall 17. In this regard, the case 72 is different from the case 16. The case 72 is fixed to the case 16 in a state where the upper side of the case 72 is stacked.

[0073] When assembling the electronic device 71, a case 72 containing the circuit board 12 is stacked on top of the case 16 containing the circuit board 12. In this state, the first cover 23 is placed on top of the case 72. With the first cover 23 in contact with the upper surface 72A of the case 72, the shaft portion of the bolt 74 is inserted through the insertion hole 24 and the insertion hole 73. At this time, the bolt 74 has a shaft portion that is longer than the vertical height dimension of the case 72. Therefore, the tip of the bolt 74 inserted through the insertion hole 24 and the insertion hole 73 protrudes downward from the lower surface 72B of the case 72 and is screwed into the screw hole 17E of the case 16. As a result, the case 16 and the case 72 are joined in a stacked state, and the first cover 23 is fixed to the upper surface 72A of the case 72.

[0074] On the other hand, with the second cover 26 in contact with the lower surface 16B of the case 16, the shaft portion of the bolt 28 is inserted through the insertion hole 27 and is screwed into the screw hole 17F of the case 16. As a result, the second cover 26 is fixed to the lower surface 16B of the case 16. As a result, the cases 16 and 72 have the circuit board 12 housed therein, and the upper opening is closed by the first cover 23, and the lower opening is closed by the second cover 26.

[0075] Thus, also in the third embodiment configured as described above, substantially the same operational effects as those of the first embodiment can be obtained. In the third embodiment, the cases 16 and 72 are joined to each other in a state where a plurality of them are stacked in the vertical direction. As a result, compared to the case where the electronic device is configured separately with a plurality of cases 16 and 72, the number of the first cover 23 and the second cover 26 can be reduced, and the manufacturing cost can be reduced.

[0076] In the third embodiment, the case where the connector 15 is disposed on the front side of both the cases 16 and 72 is illustrated. The present invention is not limited to this, and the connector 15 may be disposed at different positions in the cases 16 and 72. For example, while the connector 15 is disposed on the front side of the case 16, the connector 15 may be disposed on the rear side of the case 72, or the connector 15 may be disposed on the left side or the right side of the case 72.

[0077] In the first embodiment, the case where the circuit board 12, the case 16, the first cover 23, and the second cover 26 are all formed in a square shape has been described as an example. The present invention is not limited to this. For example, the circuit board, the case, the first cover, and the second cover may be triangular, polygonal such as pentagonal or hexagonal, circular, elliptical, or the like. That is, the shape of the case or the like can be arbitrarily adopted according to the application location. This also applies to the second and third embodiments.

[0078] In the first embodiment, the case where the electronic device 11 is mounted on the hydraulic excavator 1 equipped with the crawler-type lower traveling body 2 has been described as an example. However, the present invention is not limited to this, and it may be applied to a hydraulic excavator equipped with a wheel-type lower traveling body, or may be applied to construction machines such as a wheel loader or a hydraulic crane. This also applies to the second and third embodiments.

Explanation of Reference Numerals

[0079] 11, 51, 71 Electronic device 12, 41, 52 Circuit board 12A, 41A, 52A End (outer part) 12B, 41B, 52B Central part (inner part) 13, 14, 42, 53 Insertion hole (fixing part) 15, 54 Connector 16, 55, 72 Case 16A, 55A, 72A Upper surface 16B, 55B, 72B Lower surface 17, 56 Inner wall 18, 57 Substrate support part 19, 58 Connector fitting part 21, 59 Frame 22, 60 Slit (gap) 23, 61 First cover 26, 63 Second cover 29 Fixture 30 Bolt 31 Nut 32 Spacer

Claims

1. A circuit board, a case for housing the circuit board, a first cover for covering the upper side of the case, a second cover for covering the lower side of the case, and a fixture for fixing the circuit board to the case, and in the electronic device apparatus in which the circuit board has a fixing portion for being housed in the case via the fixture, the case has an inner wall in a frame shape with an open upper surface and a lower surface, and a frame joined to the inner wall and extending in the plane direction of the circuit board, a plurality of the frames are arranged inside the case with a predetermined gap therebetween, and the fixture is inserted and fixed in the gap between the frames. The electronic device apparatus is characterized by this.

2. The electronic device apparatus according to claim 1, wherein the frame has a structure extending radially in the plane direction of the circuit board.

3. The electronic device apparatus according to claim 1 or 2, wherein the cases are joined to each other in a state of being stacked in the vertical direction.

4. The electronic device apparatus according to claim 1, wherein the fixing portion is arranged at an outer portion and an inner portion of the circuit board.

5. The electronic device apparatus according to claim 1 or 2, wherein the circuit board has a connector.

Images