JP2011054582A - Device net apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize adverse effects on apparatus operation, data transmission or the like by effectively preventing external noise from intruding into an apparatus. <P>SOLUTION: A device net apparatus 1 is constituted such that external noise is prevented from intruding into an internal cable 6 of the device net apparatus 1 by attaching a noise countermeasure board 10 to a metallic connector 4 that is in accordance with IEC and is fixed to an apparatus chassis 3 for connecting the device net apparatus 1 to a body such as a personal computer through a signal line 5, wherein a capacitor 13 for AC coupling between the signal line 5 and the chassis 3 is mounted on the noise countermeasure board 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides a data signal that is connected to a main body of a personal computer or the like and transmitted from the main body via a signal line, such as a mass flow controller used by connecting to a network system to remotely control the flow rate. In particular, the present invention relates to a noise resistance (EMC) countermeasure technique for equipment.

In this type of device network equipment, it is necessary to provide an impedance of 1 MΩ or more on the equipment side in order to comply with a communication standard for protecting against dangerous lines of the entire network system and preventing malfunction of each equipment. An example of this will be described with reference to FIG. 5. A printed circuit board 2 on which an electronic device such as an IC or a transistor, an electronic component such as a resistor or a capacitor, or other components is mounted and fixed is installed in the chassis 3. The device net device 1 is a device net standard connector 4 (Micro-style M12 / 5 pin connector that is fastened and fixed to the chassis 3 and conforms to IEC 60947-5-2. And a signal line 5 joined to one end of the connector 4 and connected to a main body (not shown) such as a personal computer. Then, the other end side of the connector 4 and the printed circuit board 2 are connected via the cable 6 and the impedance 7 of 1 MΩ or more is interposed between the chassis 3 and the shield (drain) line, thereby satisfying the communication standard described above. A suitable network system is built.

In the network system constructed as described above, since the electromagnetic shield 8 that covers the signal line 5 that connects the main body and the device network device 1 cannot be directly connected to the chassis 3, the external noise N is generated by the signal line 5. There is a problem that it directly enters the chassis 3 of the device 1 through the unshielded portion of the device 1 and causes malfunction of the device 1 or causes data error in data transmission and transfer.

Conventionally, as a countermeasure against EMC (noise resistance) for avoiding such a problem, as shown in FIG. 5, means for forming a noise countermeasure circuit 9 composed of, for example, a conductive land and a capacitor on the printed circuit board 2. Was adopted.

  However, in the conventional EMC countermeasure as described above, since the cable 6 from the connector 4 to the printed circuit board 2 is long wired in the chassis 3, the external noise component N taken into the chassis 3 through the cable 6. However, there is a problem in that a sufficient and sufficient EMC countermeasure effect cannot be exhibited, such as leaking inside the device 1 and interfering with electronic devices and electronic components, adversely affecting device operation and data transmission.

  The present invention has been made in view of the above-described circumstances, and its purpose is to effectively prevent the entry of external noise into the device and to minimize adverse effects on device operation, data transmission, and the like. To provide device network equipment.

  In order to achieve the above object, a device network device according to the present invention is a device network device connected to a main body through a connector fixed to a chassis containing a board on which an electronic device and an electronic component are mounted. A noise countermeasure component for AC coupling between the signal line and the chassis is provided at a position closest to the connector or inside the connector.

  According to the present invention having the above-described characteristic configuration, an external noise component picked up by a signal line in a state where it cannot be directly shielded by the equipment chassis due to the conformity to the communication standard described above, the position closest to the connector. Alternatively, it is possible to escape to the chassis through a noise countermeasure component that is provided inside the connector and AC-couples between the signal line and the chassis. That is, a sufficient EMC countermeasure effect can be exhibited before the external noise component enters the long wiring portion in the device. Therefore, regardless of the length of the wiring part in the equipment, external noise components are taken into the equipment and leak from the wiring parts in the equipment and interfere with electronic devices and electronic components, thereby causing equipment operation and data transmission. There is an effect that it is possible to suppress the adverse effect on the minimum.

  In the device network device according to the present invention, the noise countermeasure component may be directly incorporated in the connector. However, as described in claim 2, a noise countermeasure substrate separately manufactured by mounting the noise countermeasure component is provided. By attaching to the connector, it is preferable to provide the noise countermeasure component at a position closest to the connector. In this case, when taking countermeasures for EMC in equipment that uses existing connectors, the excellent EMC as described above can be obtained by simply attaching a noise countermeasure board to the existing connectors without incurring the extra cost of connector replacement. A countermeasure effect can be easily provided.

  In the present invention, the noise countermeasure component is most preferably provided in close contact with the device inner end surface of the connector, but at least within a distance range of less than 20 mm from the device inner end surface of the connector, The EMC countermeasure effect can be exhibited.

It is a schematic longitudinal cross-sectional view of the device network apparatus which concerns on this invention. It is an enlarged side view of a connector. It is an enlarged surface view of a noise countermeasure board. It is an enlarged back view of a noise countermeasure board. It is the longitudinal cross-sectional view of the principal part which shows the conventional device network apparatus and the EMC countermeasure state with respect to this apparatus. (A), (b), (c) is a graph which shows a test result.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic longitudinal sectional view of a device network device according to the present invention. This device network device 1 is mounted and fixed with electronic devices such as ICs and transistors, electronic components such as resistors and capacitors, and other components. The printed circuit board 2 is installed and installed inside the chassis 3, and is connected to the personal computer via the IEC-compliant metal connector 4 fastened to the chassis 3 and the signal line 5 joined to one end of the connector 4. The other end side of the connector 4 and the printed circuit board 2 are connected via a cable 6 wired inside the chassis 3, thereby the device network device 1. A network system that can remotely control the network has been constructed.

  As shown in FIG. 2, the IEC-compliant metal connector 4 has five connector pins 4B held by a resin mold inside the metal shell 4A, and the outer peripheral female thread portion 4C of the metal shell 4A A nut 4D for fastening and fixing to the chassis 3 is screwed. The metal connector 4 is provided with a noise countermeasure board 10 that makes a noise countermeasure component, which will be described later, in close contact with the equipment-side inner end face 4a of the metal shell 4A and AC-couples the signal line 5 and the chassis 3 with each other.

The noise countermeasure board 10 is manufactured separately from the connector 4 and has a cross-shaped hole at the center of the surface through which the connector pin 4B of the connector 4 is inserted, as clearly shown in FIG. 11 is formed, and connector pin connection portions 12 that are in contact with each connector pin 4B and become conductive are formed around the end portions of the cross-shaped holes 11, and noise countermeasures are provided near the outer periphery of the substrate 10. A capacitor 13, which is an example of a component, is attached (mounted) by soldering in a state where the capacitor 13 is electrically connected to the connector pin connection portion 12. An impedance 7 of 1 MΩ or more is attached to the surface of the substrate 10. The hatched portion is a conduction region.

On the other hand, as clearly shown in FIG. 4, an annular connection portion 14 corresponding to the device-side inner end surface 4a of the metal shell 4A in the connector 4 is formed on the back surface of the noise countermeasure board 10. By soldering the noise countermeasure board 10 to the metal shell 4A of the connector 4 through the plurality of through holes 15 in a state where the portion 14 is in close contact with the device-side inner end surface 4a of the metal shell 4A, the capacitor 13 is interposed. The signal line 5 and the chassis 3 are AC coupled.

In the device network device 1 configured as described above, the external noise component input through the signal line 5 placed in a state where it cannot be directly shielded to the device chassis 3 due to the compatibility with the communication standard is connected to the connector. 4 can be released to the chassis 3 through the capacitor 13 mounted on the noise countermeasure board 10 attached to the circuit board 4, and the external noise component is surely sufficient at a stage before entering the long wiring portion in the device 1, that is, the cable 6. The EMC countermeasure effect can be exhibited. Therefore, regardless of the length of the cable 6 in the device 1, the external noise component is taken into the device 1 and interferes with an electronic device, an electronic component, and the like, resulting in device operation and data transmission. Adverse effects can be minimized.

  Incidentally, the present inventors have (a) a device that is not subjected to noise countermeasures, (b) a conventional device in which a noise countermeasure circuit is formed on a printed circuit board, and (c) as described in the above embodiment. In addition, an EMC test was conducted to confirm the EMC countermeasure effect of each of the devices of the present invention in which the noise countermeasure board was attached to the connector. The test conditions were 10 V / m, 80 MHz to 1000 MHz, and the effect was confirmed by the flow rate output of the mass flow controller as the test equipment.

  The results of the above test are as shown in FIGS. 6A, 6B, and 6C. As is apparent from these results, in the apparatus of the present invention, the external noise component is an electronic device inside the apparatus. It was confirmed that a predetermined flow rate output could be obtained without interfering with the electronic parts. Although the test results are not shown in the drawings, if noise countermeasure components are provided within a distance range of less than 20 mm from the inner end surface of the connector, the noise resistance circuit is formed on a printed circuit board, compared to conventional devices. It was also confirmed that a high EMC countermeasure effect was obtained.

In the above-described embodiment, the capacitor 13 is mounted on the noise countermeasure board 10 manufactured separately from the connector 4, and the board 10 is attached to the connector 4, so that the predetermined EMC countermeasure is used while using the existing connector as it is. However, when the capacitor 13 is directly built in the connector 4 to produce a noise countermeasure connector, and the main body and the device network device 1 are connected using the noise countermeasure connector, the same EMC countermeasure is adopted. An effect is obtained.

  Further, as a noise countermeasure component, a coil or an EMI filter may be used in addition to the capacitor.

DESCRIPTION OF SYMBOLS 1 Device net device 2 Printed circuit board 3 Chassis 4 Metal connector based on IEC 5 Signal line 10 Noise suppression board 13 Capacitor (noise suppression component)

Claims (3)

Electronic device, device net equipment connected to the main body through a connector fixed to a chassis containing a board on which electronic components are mounted,
A device network device characterized in that a noise countermeasure component for AC coupling between a signal line and the chassis is provided in a position closest to the connector or inside the connector.   2. The device network device according to claim 1, wherein the noise countermeasure component is provided at a position closest to the connector by attaching a noise countermeasure substrate separately mounted by mounting the component to the connector. 3.   3. The device network device according to claim 1, wherein the noise countermeasure component is provided within a distance range of less than 20 mm from the device-side inner end surface of the connector.

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