This application is a based on a claims priority from Japanese Patent Applications No. 2017-195316 filed on Oct. 5, 2017, the entire contest of which are incorporated herein by reference.
The present invention relates to a connector having a plurality of terminals that are electrically connected to each other.
Connectors are known widely that are equipped with a housing that holds plural terminals that are electrically connected to each other. Connectors of this type are also called joint connectors. Joint connectors are typically used being fitted in a mating connector that is connected to a trunk line and branch lines, to have the branch lines branch off the trunk line that constitutes an electric circuit.
In a case that a joint connector is used to have branch lines branch off a trunk line, noise (ringing) is prone to occur due to reflection waves mainly in the branch lines which are larger in terminal resistance than the trunk line.
To suppress such noise, in one conventional joint connector, every terminal held in a housing is provided with a noise reduction member for reducing noise (refer to Patent document 1, for example). Since the noise reduction members are provided for all of the terminals, respectively, one type of joint connector, that is, a common connector, can be applied to a number of electrical circuits.
Patent document 1: JP-A-2012-69270
Where a joint connector is used to have branch lines branch off a trunk line, noise is not prone to occur in the trunk line which is smaller in terminal resistance than the branch lines. Among the branch lines, short ones are less prone to noise like the trunk line because they are small in terminal resistance. In other words, among the plurality of terminals of a joint connector there may exist terminals that are low in the necessity to be provided with a noise reduction member.
In the above conventional joint connector, the noise reduction members are provided for all of the terminals, respectively, though there exist terminals that are low in the necessity to be provided with a noise reduction member. This results in size increase and cost increase of the joint connector as a whole. It is desirable to minimize such size increase and cost increase of a joint connector.
Furthermore, where as described above branch lines are caused to branch off a trunk line by fitting a joint connector into or with a mating connector that is connected to the trunk line and the branch lines, it is necessary to perform work of attaching terminals for connection to the mating connector to end portions of two divisional trunk lines produced by dividing the original trunk line at a position corresponding to the mating connector. It is desirable to make such work necessary for connection of the trunk line as easy as possible.
The present invention has been made in view of the above circumstances, and an object of the present invention is therefore to provide a connector that is used to have branch lines branch off a trunk line and that can suppress its size increase and cost increase and facilitate work necessary for connection of the trunk line.
To attain the above object, the present invention provides connectors having features that are described below in the form of items (1) to (5):
(1) A connector comprising:
a housing capable of being fitted in a mating housing of a mating connector;
a plurality of terminals which are held in the housing and electrically connected to each other; and
a noise reduction member which is held in the housing and disposed at at least one of the plurality of terminals so as to reduce noise occurring in the at least one of the plurality of terminals,
wherein the mating connector is connected to a brunch line among a trunk line and the brunch line constituting an electric circuit;
the connector is connected to the trunk line;
the plurality of terminals includes trunk-line connection terminals which are electrically connected to the trunk line directly and branch-line connection terminals which are electrically connected to the branch line when the housing is connected to the mating housing;
the noise reduction member is not disposed at the trunk-line connection terminals; and
the noise reduction member is disposed at at least one of the branch-line connection terminals or all of the plurality of branch-line connection terminals.
(2) The connector according to item (1), wherein the housing has a trunk wire housing portion which houses the trunk line that press-contacts with the trunk-line connection terminal.
(3) The connector according to item (1) or (2), wherein the noise reduction member is made of a material containing ferrite.
(4) The connector according to item (1), wherein the trunk-line connection terminal is a pressure contact terminal, and
the branch-line connection terminal is a male terminal or a female terminal.
(5) The connector according to item (1), wherein one of the plurality of terminals is the trunk-line connection terminal, and
the remaining terminals other than the one of the plurality of terminals is the branch-line connection terminals.
In the connector (joint connector) according to the present invention, no noise reduction member is provided for the one trunk-line connection terminal that is not prone to noise and a noise reduction member is provided for all or part of the branch-line connection terminals that are prone to noise. In this manner, where the connector is used to have branch lines branch off a trunk line, the noise reduction member(s) can be provided properly for only the terminals where noise is relatively prone to occur. As a result, size increase and cost increase of the connector as a whole can be suppressed unlike in the above-described conventional connector.
Furthermore, since the trunk line is directly brought into pressure contact with the trunk-line connection terminal which is a pressure contact terminal without intervention of the mating connector, unlike in the conventional connector, work of dividing the original trunk line and providing noise reduction members for end portions of resulting two divisional trunk lines is not necessary. This makes work of connecting the trunk line easier than in the conventional connector. Furthermore, since the trunk line need not be provided with terminals, the number of components can be reduced. And since the trunk line is not divided, a phenomenon can be prevented that the communication performance is degraded by division of the trunk line W1.
Where a plurality of connectors are connected together in series via a trunk line, the noise reduction members are not disposed at an unduly large number of locations along the trunk line which extends being connected to the plurality of connectors. Thus, when a signal is transmitted from the side of one end of the trunk line to the side of its other end, a phenomenon is not prone to occur that an output signal waveform is distorted too much with respect to an input signal waveform due to disposition of noise reduction members at a large number of locations along the trunk line. This will be described later in detail.
According to the connector of the present invention, since the trunk line that is in pressure contact with the trunk-line connection terminal is housed in the trunk wire housing portion of the housing, the load due to, for example, external force acting on the portion where the trunk line is connected to the trunk-line connection terminal can be made smaller than in a case that the trunk line is not housed in the trunk wire housing portion. As a result, the reliability of the electrical connection between the trunk-line connection terminal and the trunk line can be increased.
According to the connector of the present invention, since the noise reduction member or members are made of a material containing ferrite which is very high in noise reducing ability, the noise reducing effect can be exercised stably and reliably.
The present invention can provide a connector that is used to have branch lines branch off a trunk line and that can suppress its size increase and cost increase and facilitate work necessary for connection of the trunk line.
The present invention has been described above concisely. The details of the present invention will become more apparent when the modes for carrying out the present invention (hereinafter referred to as an embodiment) described below are read through with reference to the accompanying drawings.
A specific embodiment of the present invention will be hereinafter described with reference to the drawings.
A connector 1 according to the embodiment of the present invention will be hereinafter described with reference to the drawings. The connector 1, which is also called a joint connector, has a plurality of terminals that are electrically connected to each other. As shown in
As shown in
The housing 10 is made of a resin and is composed of a main housing 11 and a hood housing 12 which is attached to the main housing 11 from the front side.
Noise reduction member holding rooms 13 for holding respective noise reduction members 30 are formed inside a front cuboid-shaped portion of the main housing 11. In the embodiment, two noise reduction member holding rooms 13 are defined and formed so as to be arranged in the width direction. Each noise reduction member holding room 13 is a cuboid-shaped recess that conforms to the shape of each noise reduction member 30 and has a front opening. The rear wall of the noise reduction member holding rooms 13 is formed with two (upper and lower) through-holes (not shown) which extend in the front-rear direction and through which terminals 21 (21a) of the busbars 20 are inserted.
The two outer side surfaces of the front cuboid-shaped portion of the main housing 11 are formed with respective lock projections 14 which project outward in the width direction and on which the hood housing 12 is locked.
A rear cuboid-shaped portion of the main housing 11 is formed with, at two (upper and lower) levels, trunk wire housing portions 15 for housing trunk line W1. Each trunk wire housing portion 15 is a groove that is open on the rear side and penetrates through the main housing 11 in the width direction. The upper and lower trunk wire housing portions 15 are the same in shape and house the two respective wires W1s and W1g of the trunk line W1 which extends straightly. The front wall of the trunk wire housing portions 15 (grooves) is also the rear wall of the noise reduction member holding rooms 13. Thus, the upper and lower through-holes that are formed through the rear wall of the noise reduction member holding rooms 13 penetrate through the front wall of the upper and lower trunk wire housing portions 15.
A lid 17 is connected, via a hinge 16, to a bottom-rear edge of the rear cuboid-shaped portion of the main housing 11 rotatably so as to be able to close and open. The lid 17 is provided to close the openings of the two (upper and lower) trunk wire housing portions 15. A tip strip of the lid 17 is formed with a lock nail 18 at the center in the width direction. The lid 17 can be kept closed by engaging the lock nail 18 with an engagement portion 19 which is formed on the top wall of the rear cuboid-shaped portion of the main housing 11.
The noise reduction members 30 are members that are disposed so as to correspond to terminals 21 (21a) of the busbars 20 to reduce noise (e.g., noise due to reflection waves) occurring in the terminals 21 (21a) of the busbars 20. Each noise reduction member 30 is a block that is approximately shaped like a cuboid so as to conform to the shape of each noise reduction member holding room 13, and, in the embodiment, is made of ferrite. Although it is preferable that each noise reduction member 30 be made of a material containing ferrite, it may be made of any material as long as it can reduce noise occurring in the associated terminals 21. Through-holes 31 through which terminals 21 are inserted penetrate through each noise reduction member 30 at two positions in the top-bottom direction.
As shown in
The hood housing 12 is approximately shaped like a rectangular pipe. As shown in
The metal busbars 20 are a signal wire busbar 20s and a grounding wire busbar 20g which are the same in shape. In the following description, each of the busbars 20s and 20g will be referred to as a “busbar 20” unless they need to be discriminated from each other.
Each busbar 20 is formed by a plurality of (in the embodiment, two) branch-line connection terminals 21a which are arranged parallel with each other, a link portion 22 which links the rear ends of the two branch-line connection terminals 21a, and one trunk-line connection terminal 21b which is connected to one end of the link portion 22. The branch-line connection terminals 21a are male terminals and the trunk-line connection terminal 21b is a pressure contact terminal. In the following description, the branch-line connection terminals 21a and the trunk-line connection terminal 21b will be referred to as “terminals 21” unless the former need to be discriminated from the latter.
As shown in
In a state that fixing of the busbars 20s and 20g is completed, the two pairs of branch-line connection terminals 21a are located at two (upper and lower) levels and project forward beyond the front surfaces of the noise reduction members 30. In other words, an upper terminal 21a that is one of the two branch-line connection terminal 21a of the signal wire busbar 20s and a lower terminal 21a that is a corresponding one of the two terminals 21a of the grounding wire busbar 20g are arranged at the two levels in the top-bottom direction and project beyond the front surface of the main housing 11. The portions, projecting beyond the front surface of the main housing 11, of the plurality of terminals 21a (the four terminals 21a in total arranged at the two (upper and lower) levels in the top-bottom direction) are located in the internal space of the hood housing 12. Thus, the four terminals 21a in total protected from outside by the hoof housing 12.
Since as described above the noise reduction members 30 are held in the two respective noise reduction member holding rooms 13, each noise reduction member 30 is disposed so as to bridge two (upper and lower) terminals 21a (branch-line connection terminals 21a) for a signal wire and a grounding wire. As a result, noise occurring between these two branch-line connection terminals 21a is reduced.
On the other hand, in a state that fixing of the busbars 20s and 20g is completed, the trunk-line connection terminal 21b of the busbar 20s is located inside the upper trunk wire housing portion 15 and the trunk-line connection terminal 21b the busbar 20g is located inside the lower trunk wire housing portion 15. No noise reduction member 30 is provided for either of the trunk-line connection terminals 21b of the busbars 20.
After the completion of fixing of the busbars 20s and 20g, as shown in
In the state that the trunk line W1 is in direct pressure contact with the trunk-line connection terminals 21b, the lock nail 18 of the lid 17 is engaged with the engagement portion 19 of the main housing 11 by rotating the lid 17 in the closing direction, whereby the lid 17 is kept closed. As a result, the state that the trunk line W1 is held in the trunk wire housing portions 15 is maintained and the attachment of the connector 1 is completed (i.e., the connector 1 shown in
Since the trunk line W1 is housed in the trunk wire housing portions 15 in the above-described manner, the load due to, for example, external force acting on the portions where the trunk line W1 is connected to the trunk-line connection terminals 21b can be made smaller than in a case that the trunk line W1 is not housed in the trunk wire housing portions 15. As a result, the reliability of the electrical connection between the trunk-line connection terminals 21b and the trunk line W1 can be increased.
As described above, in the connector 1 according to the embodiment, the noise reduction members 30 are provided for the two respective branch-line connection terminals 21a, prone to noise, of each busbar 20 and no noise reduction member 30 is provided for the one trunk-line connection terminal 21b, not prone to noise, of each busbar 20. In this manner, where the connector 1 is used to have branch lines W2 branch off a trunk line W1, the noise reduction members 30 can be provided properly for only the terminals where noise is relatively prone to occur.
As a result, size increase and cost increase of the connector 1 as a whole can be suppressed unlike in the above-described conventional connector in which noise reduction member holding rooms and noise reduction members are provided for all of the terminals.
Furthermore, since the trunk line W1 is directly brought into pressure contact with the trunk-line connection terminals 21b which are pressure contact terminals without intervention of the mating connector 40, unlike in the conventional connector, work of dividing an original trunk line and providing noise reduction members for end portions of resulting two divisional trunk lines is not necessary. This makes work of connecting the trunk line W1 easier than in the conventional connector. Furthermore, since the trunk line W1 need not be provided with terminals, the number of components can be reduced. And since the trunk line W1 is not divided, a phenomenon can be prevented that the communication performance is degraded by division of the trunk line W1.
Next, a specific description will be made of a case that connectors 1 are used to have branch lines W2 branch off a trunk line W1 that constitutes an electric circuit. In this case, as shown in
In
Two terminals (not shown; four terminals (female terminals) in total if a signal wire terminal and a grounding wire terminal are discriminated from each other) that are connected to four electric wires in total (if electric wires W2s and W2g constituting each brunch line are discriminated from each other) are housed in the housing 41 (
The housing 41 of each mating connector 40 is fitted into the hood housing 12 of the corresponding connector 1 (see
In the example shown in
In the following, as a preparation for description of workings and advantages of the configuration shown in
In general, in an electric circuit in which branch lines W2 branch off a trunk line W1 as in Comparative Example 1, noise (ringing) due to reflection waves is prone to occur mainly in the branch lines W2 which are larger in terminal resistance than the trunk line W1. In Comparative Example 1, when reflection waves occur mainly in the branch lines W2, noise cannot be reduced because no noise reduction member 30 is provided for either of the two terminals 21 of the busbar 20.
Thus, when as indicated by arrows in
Next, Comparative Example 2 shown in
In Comparative Example 2, when a signal having the same rectangular input signal waveform as shown in
This phenomenon is thought to be due to an excessive degree of effectuation of the noise reducing effect (similar to what is called lowpass filtering) of the noise reduction members 30 because the noise reduction members 30 are disposed at many locations (more specifically, one location per connector 1 and hence three locations in total) in the route from the input side (left side) of the trunk line W1 to its output side (right side).
In the configuration shown in
This is considered due to a proper degree of effectuation of the noise reducing effect of the noise reduction members 30 because a noise reduction member 30 is provided for one trunk-line connection terminal 21b where noise is not prone to occur whereas noise reduction members 30 are provided for the two respective branch-line connection terminal 21a where noise is prone to occur.
The present invention is not limited the above embodiment, and various modifications, improvements, etc. can be made as appropriate without departing from the scope of the present invention. And the material, shape, dimensions, number (where a plurality of ones are provided), location, etc. of each constituent element of the embodiment are optional and no limitations are imposed on them as long as the present invention can be implemented.
For example, in the embodiment, as shown in
In the configuration shown in
Furthermore, in the configuration shown in
Still further, in the configuration shown in
Features of the connector 1 according to the embodiment of the present invention will be summarized below concisely in the form of items (1) to (5):
(1) A connector (1) comprising:
a housing (10) capable of being fitted in a mating housing (41) of a mating connector (40);
a plurality of terminals (21) which are held in the housing (10) and electrically connected to each other; and
a noise reduction member (30) which is held in the housing (10) and disposed at at least one of the plurality of terminals (21) so as to reduce noise occurring in the at least one of the plurality of terminals (21),
wherein the mating connector (40) is connected to a brunch line (W2) among a trunk line (W1) and the brunch line (W2) constituting an electric circuit;
the connector (1) is connected to the trunk line (W1),
the plurality of terminals (21) includes trunk-line connection terminals (21b) which are electrically connected to the trunk line (W1) directly and branch-line connection terminals (21a) which are electrically connected to the branch line (W2) when the housing (1) is connected to the mating housing (41);
the noise reduction member (30) is not disposed at the trunk-line connection terminals (21b); and
the noise reduction member (30) is disposed at at least one of the branch-line connection terminals or all of the plurality of branch-line connection terminals (21a).
(2) The connector (1) according to item (1), wherein the housing (10) has a trunk wire housing portion (15) which houses the trunk line (W1) that press-contacts with the trunk-line connection terminal (21b).
(3) The connector according to item (1), wherein the noise reduction member (30) is made of a material containing ferrite.
(4) The connector according to item (1), wherein
the trunk-line connection terminal (21b) is a pressure contact terminal, and
the branch-line connection terminal (21a) is a male terminal or a female terminal.
(5) The connector according to item (1), wherein
one of the plurality of terminals (21) is the trunk-line connection terminal (21b), and
the remaining terminals other than the one of the plurality of terminals is the branch-line connection terminals (21a).
Number | Date | Country | Kind |
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2017-195316 | Oct 2017 | JP | national |