JP4699958B2 - Branch connector - Google Patents

Description

  The present invention relates to a branch connector, and particularly to reduce waveform distortion due to reflection at a branch portion of a communication line.

  In recent years, with the increase in functions of automobiles, electronic control units (hereinafter referred to as ECUs: Electronic Control Units) mounted on automobiles have become higher performance, and the number thereof tends to increase. That is, a plurality of ECUs are connected by a communication line to constitute an in-vehicle LAN. Since an in-vehicle LAN such as CAN (Controller Area Network) adopted in many automobiles is a network of bus topology, each ECU is connected to the in-vehicle LAN via a communication line that is a branch line connected to the CAN bus. .

  The CAN communication line has a pair of CAN_H and CAN_L, and a communication line called a twisted pair cable is formed by weaving the pair of communication lines in a spiral shape. The pair of communication lines (CAN_H, CAN_H) are differential transmission balanced communication lines that transmit signals by a potential difference therebetween.

  By the way, in order to cope with the increase in the number of ECUs, an in-vehicle LAN configured to connect branch lines formed of a plurality of communication lines in a star shape at one point of the communication lines constituting the CAN bus may be configured. However, when the communication line is branched and connected to a plurality of points at one point, an electrical signal is reflected due to impedance mismatching, which may cause a problem that the length of the branch line is limited.

  Patent Document 1 discloses a configuration of a star-connected data communication system. In this data communication system, attenuation means comprising a ferrite core is provided in the vicinity of the branch point of each star-connected communication line, and load impedance is provided at the branch point, so that the branch portion is approximately viewed from the branch line side. It is described that it is terminated with the impedance of a branch line. That is, it is described that the generation of reflected waves caused by impedance mismatch at the branch connection is suppressed.

JP 7-700463 Gazette

  However, particularly in a communication line configured to branch from one point to a plurality of points, the impedance at the branch point becomes a parallel combined resistance of the impedances of the branch lines. It was extremely difficult to accurately match the impedance. Also, if the ferrite core is used to match the impedance of the branch point seen from the branch line side with the impedance of the communication line of the branch line, at least in the high frequency band, the size of the ferrite core must be increased, and the branch The problem is that the connector becomes large.

  Furthermore, in order to match the impedance at the branch point, it is necessary to increase the impedance by the attenuation means inserted in each branch line, thereby causing a problem that the signal itself communicated via the CAN bus is attenuated. .

  To solve the above problem, a noise filter circuit having a minimum necessary electrical characteristic for attenuating high frequency noise due to a reflected wave generated at the branch point is provided instead of matching the impedance at the branch point. I can think of it. However, when such a noise filter circuit is provided, it becomes difficult to dispose each element constituting the filter circuit in the vicinity of the branch portion in the branch connector whose density is increased.

  Although it may be possible to reduce the size by using a chip-type element that can be surface-mounted as the resistor and the coil, a plurality of elements (for example, to form a noise filter circuit on each of a pair of signal lines) In order to connect both resistors and coils to form branch points of a large number of communication lines, a large area is required for mounting each element, and there is a problem that the branch connector becomes large.

  The present invention has been made in view of the above problems, and a communication line that constitutes a branch line by reflection at a branch point while having a simple configuration that can easily achieve downsizing at a branch point of a balanced transmission line for differential transmission. It is an object of the present invention to provide a branch connector that can quickly attenuate high-frequency noise generated inside.

In order to solve the above problems, as a first invention,
A branch connector having a pair of communication lines constituting a balanced communication line for differential transmission, into which terminal plugs of a plurality of paired wires are fitted,
A plurality of terminals respectively connected to one first communication line of each of the paired wires;
A substrate fixed to a base end portion of the plurality of terminals;
A resistor and a coil having one end connected to each terminal and the other end connected to a branch connection pattern on the substrate;
And a joint bus bar having a plurality of branch connection terminal portions respectively connected to the other second communication line of each of the paired wires.

Preferably, the pair of communication lines constituting the differential transmission balanced communication line is a twisted pair electric wire or a shielded twisted pair electric wire.
According to the configuration of the present invention, among the paired wires constituting one balanced transmission line for differential transmission, a signal sent via the first communication line includes a terminal connected to the first communication line, It flows in the branch connection pattern formed on the substrate through the resistor connected to the terminal and the parallel connection circuit of the coil. Since the branch connection pattern is connected to the plurality of resistors and the other end of the coil, the signal is sent to the other connection through the resistor and coil parallel connection circuit and the terminals connected to the resistor and the coil. Sent to one communication line.

  Therefore, in the portion of the branch connection pattern that constitutes the branch point of the branch connector, reflection of the signal occurs due to impedance mismatch, but each time high frequency noise generated by this reflection is reflected, it is attenuated by a filter circuit comprising a resistor and a coil. be able to. The peak (or valley) of the signal passes through the filter circuit only once, whereas the peak (or valley) of the reflected wave attenuates through the filter circuit every time it is reflected. Can be increased. The filter circuit is designed to attenuate signal components other than the signal band, but it is preferable to reduce the attenuation as much as possible except for the frequency band of ringing due to reflection. Thus, even if the attenuation amount of the reflected wave obtained by passing through the filter circuit once is set small, ringing generated in the communication line to which the filter circuit composed of the resistor and the coil is attached is effectively attenuated. be able to.

Moreover, the signal sent via the 2nd communication line among a pair of communication lines which comprise one communication line is sent out to another communication line directly branched-connected in the joint bus bar. At this time, reflection due to impedance mismatch at the branch point also occurs in the second communication line, but the pair of communication lines constituting the balanced communication line for differential transmission affect each other to prevent noise from entering. Therefore, the high-frequency noise in the second communication line can be attenuated by the high-frequency noise attenuation means using the resistor and the coil provided in the first communication line constituting the balanced transmission line for differential transmission.
In addition, it is preferable that the magnitude | size of the electrical characteristic of each element (resistor, coil) is set to twice the optimal magnitude | size when providing a filter circuit in both of a pair of communication lines.

Thus, the number of resistors and coils can be reduced by forming a filter circuit composed of resistors and coils only in a portion of the pair of communication lines connected to the first communication line. Therefore, since the number of resistors and coil attachment terminals formed on the substrate can be reduced, the area of the substrate can be reduced and the size of the branch connector can be reduced.
Moreover, since the 2nd communication line is comprised so that the some branch connection terminal part formed in the joint bus bar may be connected, it becomes unnecessary to connect a board | substrate to this joint bus bar. Therefore, the area of the substrate connected to the first communication line can be increased, and elements can be arranged without difficulty.
In addition, since the area of the substrate is large, all necessary elements can be mounted on one surface, and manufacturing is easier than in the case where elements are mounted on both the front and back surfaces, and the reliability can be improved accordingly.

  Furthermore, as the number of elements to be connected decreases, the assembly process can be reduced, and the manufacturing cost can be reduced. In addition, by using the substrate, it becomes easy to connect the resistor and the coil to each terminal, and the connection state of the resistor and the coil can be stabilized.

  In addition, since the waveform distortion can be reduced by attenuating high-frequency noise generated in the branch-connected communication line, the length of each communication line connected to the branch connector of the present invention can be increased.

Further, as a second invention, a terminal connector of a plurality of paired electric wires provided with a pair of communication lines constituting a balanced transmission line for differential transmission is a branch connector to be fitted,
A plurality of terminals respectively connected to one first communication line of each of the paired wires;
A resistor and a coil having one end connected to the base ends of the plurality of terminals;
A branch connection conductor connected to the other end of the resistor and coil;
A joint bus bar having a plurality of branch connection terminal portions respectively connected to the other second communication line of each of the pair wires;
A resin holding material that molds the resistor, the coil, the branch connection conductor, and the base end of the terminal connected to the resistor and the coil;
A branch connector is provided.

The paired electric wires of the second invention are also preferably twisted pair electric wires or shielded twisted pair electric wires.
According to the configuration of the second invention, the signal sent via the first communication line among the pair of communication lines constituting one balanced transmission line of differential transmission is connected to the first communication line. It flows to a branch connection conductor formed of a strip-shaped bus bar or the like through a terminal, a resistor and a parallel connection circuit of coils connected to these terminals.
In addition, since a plurality of resistors and coils are connected to the branch connection conductor, the signal is connected to the other first communication line via a parallel connection circuit of the resistor and the coil and a terminal connected to the resistor and the coil. Sent out.
In addition, since the base end of the terminal, resistor, coil and branch connection conductor are molded with a resin holding material, the connection state of each part can be stably maintained, and further miniaturization is achieved by not using a substrate. can do.

  Therefore, in the portion of the branch connection conductor constituting the branch point of the branch connector, signal reflection occurs due to impedance mismatch, and high frequency noise generated by this reflection passes through the filter circuit composed of a resistor and a coil each time it is reflected. Can be attenuated. That is, ringing that occurs in the first communication line to which the filter circuit including the resistor and the coil is attached can be efficiently attenuated.

  Of the pair of communication lines constituting one communication line, a signal sent via the second communication line is sent to another communication line that is directly branch-connected at the joint bus bar. Although reflection due to impedance mismatching occurs, the high frequency noise in the second communication line can be attenuated by the high frequency noise attenuation means by the resistor and the coil provided in the first communication line constituting the balanced transmission line for differential transmission. Is possible. In addition, it is preferable that the magnitude | size of the electrical characteristic of each element (resistor, coil) is set to 2 times the optimal magnitude | size when providing a filter circuit in both of a pair of communication lines.

  That is, the number of resistors and coils can be reduced by forming a filter circuit composed of resistors and coils only in a portion of the pair of communication lines connected to the first communication line. Can be arranged freely, and the size of the branch connector can be reduced.

  In addition, since the waveform distortion can be reduced by attenuating high-frequency noise generated in the branch-connected communication line, the length of each communication line connected to the branch connector of the present invention can be increased.

  The resistor is disposed in a direction opposite to the coil with the base end portion of the terminal as a center, and the resistor and the coil collectively attenuate signal components of reflected waves generated in a pair of communication lines. It is preferable to have electrical characteristics that can form a circuit.

  According to the said structure, since resistance and a coil can be efficiently arrange | positioned at the base end part of one terminal, size reduction can be achieved.

  As described above, according to the present invention, in the branch connector having a pair of communication lines constituting a balanced communication line for differential transmission and fitted with terminal plugs of a plurality of paired wires, the pair of communication lines The number of resistors and coils can be reduced by forming a filter circuit composed of resistors and coils only in the portion connected to the first communication line, and the resistors and coils attached to the substrate can be reduced accordingly. Since the number of terminals can be reduced, downsizing can be achieved. In addition, since the waveform distortion can be reduced by attenuating high-frequency noise generated in the branch-connected communication line, the length of each communication line connected to the branch connector of the present invention can be increased.

Embodiments of the present invention will be described with reference to the drawings.
1 to 3 are views showing the configuration of the branch connector 1 according to the first embodiment of the present invention. FIG. 1 is an exploded perspective view of the branch connector 1, and FIG. FIG. 3 is a view of the branch connector 1 as viewed from the rear side (in this specification, the receiving port of the branch connector 1 is the front side), and FIG.

A branch connector 1 according to the first embodiment is a connector that branches and connects twisted pair electric wires including a first communication line 2A and a second communication line 2B that constitute a balanced transmission line 2 for differential transmission.
The branch connector 1 includes a plurality of terminals 3 connected to the first communication line 2A among the twisted pair wires, a substrate 4 for fixing the base end portions 3a of the terminals 3 in a juxtaposed state, and one end to each of the terminals 3. A resistor 5 and a coil 6 for connecting the other ends 5b and 6b to the branch connection pattern 4a on the substrate 4 and a plurality of branch connection terminal portions 7a connected to the other second communication line 2B are connected continuously. A joint bus bar 7 formed integrally with the portion 7 b and a cover body 8 for accommodating and protecting the substrate 4 and the joint bus bar 7 are provided.

  The distal ends of the first and second communication lines 2A and 2B can be individually inserted into the receiving ports 8a of the cover body 8, and the first and second communication lines 2A and 2B are connected to the terminals in the inserted state. 3 and a terminal plug 2 </ b> C that is fitted and connected to the branch connection terminal portion 7 a of the joint bus bar 7.

  The terminal 3 is made of a rod-shaped body made of a metal having good conductivity, and is formed at the back of the cover body 8 in accordance with the number of balanced communication lines 2 to be branched and connected to the interval of the receiving port 8a. The wall 8b is inserted into a hole 8c (shown only in FIG. 3) and fixed in parallel.

  The substrate 4 is formed with holes 4b in accordance with the distance between the terminals 3, the base end portion 3a of the terminals 3 is inserted into the holes 4b, and the terminals 3 are soldered to soldering bats 4c provided on the back side of the holes 4b. The terminal 3 is positioned and fixed at the same time.

The resistor 5 and the coil 6 are chip-shaped elements that are surface-mounted by soldering to the pad 4c and the branch connection pattern 4a. Thus, by using the resistor 5 and the coil 6 as chip-type elements, the size can be reduced and the surface area of the substrate 4 can be reduced.
In the present invention, the resistor 5 and the coil 6 are not limited to the chip-like element, and an element for insertion type mounting may be used.
All the resistors 5 mounted on the substrate 4 and the other end side of the coil 6 are connected to one by the branch connection pattern 4 a of the substrate 4, so that each terminal 3 is connected from the parallel connection circuit of the resistor 5 and the coil 6. It connects in the star shape centering on the branch connection pattern 4a through the filter circuit F which becomes.

  Further, since the resistor 5 is mounted on the substrate 4 so as to be located on the opposite side of the coil 6 with the base end portion 3a of the terminal 3 as the center, the interval W between the terminals 3 can be formed narrowly. The branch connector 1 can be reduced in size.

  Note that the branch connector 1 of the present invention forms the filter circuit F only on the first communication line 2A and is unbalanced, so that the two first and second communication lines 2A are used by using one filter circuit F. , 2B, the electrical characteristics of the resistor 5 and the coil 6 are set to twice the optimum value for attenuating the high frequency noise in one first communication line 2A.

  The joint bus bar 7 is formed by punching a conductive metal plate, and a plurality of branch connection terminal portions 7 a are projected from the connection portion 7 b in parallel with the terminals 3. The connecting portion 7 b of the joint bus bar 7 is inserted into a hole 8 d formed in the inner wall surface 8 b of the cover body 8 and fixed to the cover body 8.

  The cover body 8 includes a main body 8A and a lid body 8B located on the back surface of the main body 8A. The lid body 8B protects the substrate 4. The cover body 8 is formed of a hard synthetic resin. In the cover body 8 shown in the present embodiment, guide ribs 8d are provided in the receiving ports 8a through which the terminal plugs 2C are individually inserted and removed.

By using the branch connector 1 configured as described above and inserting the terminal plug 2C into the receiving port 8a, the communication lines 2 connected via the terminal plugs 2C can be branched and connected in a star shape. The number of balanced communication lines 2 connected to the branch connector 1 can be arbitrarily increased or decreased. In this embodiment, for example, seven balanced communication lines 2 can be connected.
The terminal plug 2C connects a plurality of pairs of communication lines 2A and 2B to one terminal plug 2C so that a plurality of communication lines 2 including a pair of communication lines 2A and 2B can be collectively inserted into the receiving port 8a. You may comprise as follows.

  As the number of balanced communication lines 2 connected to the branch connector 1 increases, impedance mismatching occurs in the branch connector 1 and signal reflection occurs. The high-frequency noise generated thereby is caused by the resistance 5 and the coil 6. It can be attenuated by a filter circuit F comprising a parallel connection circuit. That is, the reflected wave appears as high-frequency noise, but is attenuated by the filter circuit F every time reflection occurs at the ends of the first and second communication lines 2A and 2B serving as branch lines, so that the high-frequency noise is effective. Can be attenuated.

4 to 6 show a branch connector 10 according to a second embodiment of the present invention.
4 to FIG. 6, the same members as those in FIG. 1 to FIG.

  4 to 6, reference numeral 11 denotes a terminal connected to the first communication line 2 </ b> A of the twisted pair electric wire, and reference numeral 12 denotes a branch made of a strip-shaped bus bar connected to the base end portion 11 a of the terminal 11 via the resistor 5 and the coil 6. Connection conductor. Reference numeral 13 denotes a resin holding material, which molds the resistor 5, the coil 6, the base end portion 11 a of the terminal 11, and the branch connection conductor 12.

  In the present embodiment, the resistor 5 and the coil 6 are connected to the terminal 11 by forming the soldering surface 11b at the base end portion 11a of the terminal 11 and the ends 5a and 6a of the resistor 5 and the coil 6 to the soldering surface 11b. Soldering. Further, the other end 5a of all the resistors 5 and the other end 6b of the coil 6 are connected to the branch connection conductor 12 in parallel.

  The resin holding member 13 molds the base end portion 11 a of the terminal 11 to position and fix the terminal 11, and also connects the resistor 5, the coil 6, the base end portion 11 a of the terminal 11 and the branch connection conductor 12. It protects so that external force is not directly applied to.

  Also in the second embodiment, the joint bus bar 7 in which a plurality of branch connection terminal portions 7a connected to the other second communication line 2B are integrally formed with the continuous portion 7b, the joint bus bar 7 and the resin holding A cover body 8 including a main body 8A for accommodating and protecting the material and a lid body 8B is provided.

  The branch connector 10 of the second embodiment branches and connects the first communication line 2A via each terminal 11 and the branch connection conductor 12, and branches and connects the second communication line 2B via the joint bus bar 7. Since the filter circuit F is formed between the one communication line 2A and the branch connection conductor 12, high-frequency noise caused by impedance mismatch at the branch point can be attenuated early, and the waveform can be improved.

  Moreover, since the branch connector 10 of 2nd Embodiment is formed without using a board | substrate, it can reduce manufacturing cost.

It is a disassembled perspective view which shows the branch connector of 1st Embodiment. It is the figure which looked at the principal part of the said branch connector from the back. It is a longitudinal cross-sectional view of the said branch connector. It is a disassembled perspective view which shows the branch connector of 2nd Embodiment. It is the figure which looked at the principal part of the said branch connector from the back. It is a longitudinal cross-sectional view of the said branch connector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10 Branch connector 2 Balanced communication line 2A 1st communication line 2B 2nd communication line 2C Terminal plug 3,11 Terminal 3a, 11a Terminal base part 4 Board | substrate 4a Branch connection pattern 5 Resistance 6 Coil 7 Joint bus bar 7a Branch connection Terminal section 12 Branch connection conductor 13 Resin holding material

Claims (4)

A branch connector having a pair of communication lines constituting a balanced communication line for differential transmission, into which terminal plugs of a plurality of paired wires are fitted,
A plurality of terminals respectively connected to one first communication line of each of the paired wires;
A substrate fixed to a base end portion of the plurality of terminals;
A resistor and a coil having one end connected to each terminal and the other end connected to a branch connection pattern on the substrate;
A joint bus bar having a plurality of branch connection terminal portions respectively connected to the other second communication line of each of the pair wires;
A branch connector comprising: A terminal connector of a plurality of paired wires provided with a pair of communication lines constituting a balanced communication line for differential transmission is a branch connector to be fitted,
A plurality of terminals respectively connected to one first communication line of each of the paired wires;
A resistor and a coil having one end connected to the base ends of the plurality of terminals;
A branch connection conductor connected to the other end of the resistor and coil;
A joint bus bar having a plurality of branch connection terminal portions respectively connected to the other second communication line of each of the pair wires;
A resin holding material that molds the resistor, the coil, the branch connection conductor, and the base end of the terminal connected to the resistor and the coil;
A branch connector comprising: The resistor and the coil are connected and arranged on both sides of the base end portion of the terminal, and
The branch connector according to claim 1 or 2, wherein a filter circuit for attenuating a signal component of a reflected wave generated in the first communication line and the second communication line of the pair electric wire is formed in the resistor and the coil.   The branch connector according to any one of claims 1 to 3, wherein the pair electric wire including a pair of communication wires constituting the differential transmission balanced communication line is a twisted pair electric wire or a shielded twisted pair electric wire.

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