阅读说明：本技术 同轴连接器 (Coaxial connector ) 是由 土屋博崇 笹木仁人 高野龙太郎 芹沢胜久 田口典英 于 2019-05-22 设计创作，主要内容包括：本发明提供一种同轴连接器，其能使外形小型化并且能抑制流过同轴连接器的高频信号的损耗。在进行小型化而使直径变小的筒状壳体的内侧同轴配置的中心接触件的筒状的连结部形成有开口。由于形成开口的部位处的电容降低，特性阻抗接近同轴线路的特性阻抗，因此，即使将同轴连接器小型化，也能抑制高频信号的损耗。(The invention provides a coaxial connector, which can miniaturize the appearance and restrain the loss of high-frequency signals flowing through the coaxial connector. An opening is formed in a cylindrical coupling portion of a center contact coaxially disposed inside a cylindrical housing which is made smaller in diameter. Since the capacitance at the position where the opening is formed is reduced and the characteristic impedance is close to that of the coaxial line, the loss of the high-frequency signal can be suppressed even if the coaxial connector is miniaturized.)

1. A coaxial connector is provided with:

a center contact connected to a center conductor of the coaxial line;

a cylindrical case connected to an outer conductor of the coaxial line; and

an insulator disposed between the center contact and the cylindrical housing and coaxially supporting the cylindrical housing around a center axis of the center contact,

the coaxial connector brings the cylindrical housing and the center contact into contact with an outer contact and a mating center contact of a mating coaxial connector to be fitted and connected, respectively,

the coaxial connector is characterized in that it is provided with,

the center contact has: a center conductor connecting portion connected to a center conductor of the coaxial line on one side along the center axis; a center contact portion that is in contact with the counterpart center contact at the other side; and a cylindrical connecting portion connecting the center conductor connecting portion and the center contact portion,

the periphery of the coupling portion of the center contact is covered with the cylindrical housing via the insulator,

at a joint of the connecting portion formed in a tubular shape by bending a conductive metal plate around the central axis, an opening for increasing a characteristic impedance of a portion of the connecting portion to be close to a characteristic impedance of the coaxial line is formed.

2. The coaxial connector of claim 1,

the opening is formed in a portion of the connection portion that does not overlap a signal transmission path of the center contact, which connects a connection position with the center conductor of the coaxial line and a contact position with the center contact on the mating side at a shortest distance.

3. The coaxial connector of claim 1 or 2,

a plurality of coaxial connecting units including the center contact, the cylindrical housing, and the insulator are mounted in parallel to the insulating housing body in an insulated manner from each other.

Technical Field

The present invention relates to a coaxial connector connected to a terminal of a coaxial line and fitted and connected to a mating coaxial connector, and more particularly, to a coaxial connector in which a characteristic impedance of a connection portion connected to the mating coaxial connector is made to approach a characteristic impedance of the coaxial line.

Background

Conventionally, a coaxial cable as a coaxial line is used as a transmission line for transmitting a high-frequency signal between electronic devices, and in wiring between electronic devices via the coaxial cable, a coaxial connector is connected to an end of the coaxial cable in advance, and the coaxial cable is detachably wired to the electronic devices as a structure for fitting and connecting the coaxial connector to a counterpart coaxial connector on the electronic device side.

Generally, a coaxial cable is formed by coaxially stacking a dielectric layer, an outer conductor including a braided wire, and an outer sheath serving as an outer covering around a center conductor from the inside toward the outside. When the relative dielectric constant of the dielectric layer is epsilon, the inner diameter of the outer conductor is D, and the outer diameter of the central conductor is D, the characteristic impedance Z of the coaxial cable is₀By

It is shown that the parts constituting the coaxial cable are formed in the same thickness and the same shape so that the same characteristic impedance Z is provided at any position along the coaxial cable₀。

The coaxial connector connected to the end of the coaxial cable includes: a center contact connected to the center conductor; a cylindrical housing connected to the external conductor; and an insulator for coaxially supporting the cylindrical housing around a center axis of the center contact, and for fitting and connecting the cylindrical housing to the mating coaxial connector by fitting the cylindrical housing to the outer contact of the mating coaxial connector at an insertion position where the center contact is in contact with the mating center contact of the mating coaxial connector.

Albeit at such a characteristic impedance Z of the coaxial connector_cThe characteristic impedance Z with the coaxial cable₀The respective components are designed in a matching manner so that the transmission loss of the high-frequency signal does not occur even if the coaxial connector is connected to the end of the coaxial cable, but in recent years, the transmission loss of the high-frequency signal does not occurThe characteristic impedance Z of the coaxial connector is reduced by reducing the inner diameter of the cylindrical housing of the coaxial connector_cReduced characteristic impedance Z with coaxial cable₀And not matched.

That is, the inductance per unit length of the transmission line is set to L₀And the capacitance per unit length is set to C₀Then the characteristic impedance Z on the transmission path of the coaxial connector_cBy

Thus, when the diameter of the cylindrical case is small, the distance from the center contact is close to the capacitance C per unit length₀Rise, characteristic impedance Z_cReduced characteristic impedance Z with coaxial cable₀And not matched.

Therefore, as shown in fig. 10, in the coaxial connector 100 described in patent document 1, an opening 102 is provided to penetrate an elastic contact piece 101a at the distal end of a cylindrical housing 101, thereby increasing the characteristic impedance Z of the coaxial connector_cSo as to approach the characteristic impedance Z of the coaxial cable 110₀。

Hereinafter, the conventional coaxial connector 100 will be described with reference to fig. 10 and 11. The coaxial connector 100 is constituted by: a cylindrical case 101 connected to an outer conductor 111 of the coaxial cable 110 and having an opening 102 provided through a proximal end side of an elastic contact piece 101a provided continuously at a distal end thereof; a center contact 104 connected to a center conductor, not shown, of the coaxial cable 110; and an insulator 103 disposed between the center contact 104 and the cylindrical housing 101, and coaxially supporting the cylindrical housing 101 around the center axis of the center contact 104. The outer diameter of the cylindrical housing 101 is substantially equal to the inner diameter of the outer contact 122 of the mating coaxial connector, and at a position where the mating center contact 121 of the mating coaxial connector is inserted into the cylindrical center contact 104 and contacts with each other, the elastic contact piece 101a at the distal end of the cylindrical housing 101 elastically contacts with the inner wall of the outer contact 122, and the mating coaxial connector is fitted and connected to the coaxial connector 100.

As shown in fig. 11, if the opening 102 is not formed at the connection position where the coaxial connector 100 is fitted and connected to the coaxial connector on the other side, the capacitor C formed between the center contact 104 and the elastic contact piece 101a (the cylindrical housing 101) is interposed by the insulator 103 as a dielectric body₀' by providing the opening 102 through the center contact, a capacitance C is obtained which is formed between the center contact 104 and the outer contact 122 which is farther from the elastic contact piece 101a than the insulator 103 which is a dielectric body and an air layer are interposed therebetween₀' greater capacitance C₀. Therefore, according to the coaxial connector 100, the characteristic impedance Z of the coaxial connector 100 is set at the position where the opening 102 is formed_cIncrease to approach the characteristic impedance Z of the coaxial cable 110₀Transmission loss can be prevented.

However, in the above-described conventional coaxial connector 100, in a state where the opening 102 of the cylindrical housing 101 is not covered with the external contact 122 of the counterpart coaxial connector, the center contact 104 is exposed to the outside through the opening 102, and therefore, a high-frequency signal flowing through the center contact 104 emits unwanted radiation and noise, or external noise flows through the center contact 104, and there is a possibility that a failure may occur.

Further, since the opening 102 is formed in the elastic contact piece 101a of the cylindrical housing 101 fitted and connected to the external contact 122 of the coaxial connector on the mating side, there are problems that the reliability of the connection between the external contact 122 and the elastic contact piece 101a is impaired, or the contact resistance between the external contact 122 and the cylindrical housing 101 is unstable.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a coaxial connector which can be downsized and can suppress loss of a high-frequency signal flowing through the coaxial connector.

Further, an object of the present invention is to provide a coaxial connector capable of completely shielding the periphery of a center contact and adjusting the characteristic impedance of a transmission path.

Means for solving the problems

In order to achieve the above object, a coaxial connector according to a first aspect includes: a center contact connected to a center conductor of the coaxial line; a cylindrical case connected to an outer conductor of the coaxial line; and an insulator disposed between the center contact and the cylindrical housing, and coaxially supporting the cylindrical housing around a center axis of the center contact, the coaxial connector having the cylindrical housing and the center contact in contact with an outer contact and a counterpart center contact of a counterpart coaxial connector to be fitted and connected, respectively, the center contact comprising: a center conductor connecting portion connected to a center conductor of the coaxial line on one side along the center axis; a center contact portion that is in contact with the counterpart center contact at the other side; and a cylindrical connection portion connecting the center conductor connection portion and the center contact portion, wherein the periphery of the connection portion of the center contact is covered by the cylindrical housing via an insulator, and an opening for increasing the characteristic impedance of the connection portion to approach the characteristic impedance of the coaxial line is formed at a joint of the connection portion formed by bending the conductive metal plate around the center axis to be cylindrical.

By forming the opening in the coupling portion, the distance between the cylindrical housing facing the portion of the coupling portion where the opening is formed and the coupling portion of the center contact is increased, and the capacitance C per unit length formed between the cylindrical housing and the center contact is increased₀This decreases the characteristic impedance.

Since the opening is formed in the center contact whose periphery is covered with the cylindrical housing, the center contact is shielded without leakage by the cylindrical housing even if the opening is formed.

Further, since the opening is formed in the coupling portion of the center contact which is not contacted by the mating center contact, the connection with the mating coaxial connector is not affected.

Openings are formed at the joints of the connecting portions by forming symmetrically shaped recesses at both side edges of the conductive metal plate bent into a cylindrical shape to become the joints of the connecting portions.

The coaxial connector according to the second aspect is characterized in that the opening is formed in a portion of the connection portion that does not overlap with a signal transmission path of the center contact that connects the connection position with the center conductor of the coaxial line and the contact position with the center contact on the other side at the shortest distance.

Since the high-frequency signal flowing through the center contact flows through the shortest signal transmission path of the connection portion, a new inductance due to the winding of the opening is not generated.

The coaxial connector of the third aspect is characterized in that a plurality of coaxial connecting units including the center contact, the cylindrical shell, and the insulator are fitted in parallel to the insulating housing body while being insulated from each other.

Even if an opening is formed in the center contact of the coaxial connecting unit, the periphery thereof is completely surrounded by the cylindrical housing and shielded from other coaxial connecting units.

Effects of the invention

According to the first aspect of the invention, even if the entire size is reduced and the diameter of the cylindrical housing connected to the outer conductor of the coaxial line is set small, the characteristic impedance is increased by simple processing for forming the opening in the center contact so as to be close to the characteristic impedance of the coaxial line, thereby suppressing the signal loss.

Since the opening is formed in the center contact whose periphery is covered with the cylindrical case, the center contact is shielded from the outside, and entry of unnecessary radiation and noise can be prevented.

Further, even if the center contact is opened, the connection with the counterpart coaxial connector is not affected.

Instead of punching the connection portion to form the opening, the opening is naturally formed in the connection portion by a step of punching a conductive metal plate as a cylindrical connection portion and bending the metal plate into a cylindrical shape around a central axis.

According to the invention of the second aspect, the characteristic impedance can be adjusted only by changing the capacitance without generating a new inductance by forming the opening.

According to the third aspect of the present invention, since the center contact of each coaxial connecting unit is shielded from the other coaxial connecting units by the cylindrical housing surrounding the center contact, crosstalk does not occur between the center contacts of the plurality of poles.

Drawings

Fig. 1 is a perspective view of a coaxial connector 1 according to a first embodiment of the present invention and a mating coaxial connector 70 to be fitted and connected to the coaxial connector 1.

Fig. 2 is an exploded perspective view showing parts of the coaxial connection unit 10 constituting the coaxial connector 1.

Fig. 3 (a) is a perspective view of the center contact 3 connected to the center conductor 51 of the coaxial cable 50 as viewed from obliquely above the rear surface, and fig. 3 (b) is a perspective view of the center contact 3 connected to the center conductor 51 of the coaxial cable 50 as viewed from obliquely above the front surface.

Fig. 4 (a) is a front view of the center contact 3, fig. 4 (b) is a plan view of the center contact 3, and fig. 4(c) is a rear view of the center contact 3.

Fig. 5 is a partially cut-away exploded perspective view of the coaxial connection unit 10.

Fig. 6 is a longitudinal sectional view of the coaxial connection unit 10.

Fig. 7 is a longitudinal sectional view of the coaxial connecting unit 10 connected to the counterpart coaxial connecting unit 71.

Fig. 8 is a cross-sectional view of the coaxial connection unit 10 taken through the opening 6 of the coupling portion 5.

Fig. 9 is a TDR measurement chart for comparison according to the presence or absence of the opening 6 of the center contact 3.

Fig. 10 is a perspective view of a conventional coaxial connector 100.

Fig. 11 is a longitudinal sectional view of the coaxial connector 100 connected to the counterpart coaxial connector, taken through the opening 102.

Description of the reference numerals

1: a coaxial connector; 2: an insulating base body; 3: a center contact; 4: a central conductor connecting portion; 5: a connecting portion; 5 a: seaming; 6: an opening; 7: a center contact portion; 11: a cylindrical housing; 15: an insulator; 50: coaxial cables (coaxial lines); 51: a center conductor; 54: an outer conductor; 70: a counterpart side coaxial connector; 72: the opposite side center contact (center pin); 73: an external contact.

Detailed Description

Hereinafter, a coaxial connector 1 according to an embodiment of the present invention will be described with reference to fig. 1 to 9. In this specification, the structure of each part will be described with reference to a front surface as illustrated in fig. 4 (a), a rear surface as illustrated in fig. 4(c), a vertical direction as illustrated in fig. 4 (a), a front direction as illustrated in a horizontal direction, a left direction, and a rear direction as illustrated in a right direction.

As shown in fig. 1 and 2, the coaxial connector according to the present embodiment is a four-pole coaxial connector 1 in which four coaxial connecting units 10 connected to the ends of four coaxial cables 50 as coaxial lines are mounted in parallel to each other in a rectangular parallelepiped insulating housing 2 in an insulated manner, and the coaxial connector 1 is fitted into a mating coaxial connector 70 mounted on a circuit board not shown in the drawings, and the four coaxial connecting units 10 are connected to four mating coaxial connecting units 71 of the mating coaxial connector 70, thereby connecting each of the coaxial cables 50 to a high-frequency signal pattern of the circuit board.

Each coaxial cable 50 connected to the coaxial connector 1 is formed by coaxially laminating an intermediate dielectric body 52, a shield layer 53 made of aluminum foil, an outer conductor 54 made of braided wire, and an outer sheath 55 covering the outer periphery in this order from the inside around a center conductor 51 wired along the center axis of a cylindrical cable, and the shield layer 53 and the outer conductor 54 connected to each other via the intermediate dielectric body 52 and the center conductor 51 are arranged at a constant distance from each other, whereby the characteristic impedance Z of the coaxial cable 50 is set here₀50 omega is reached.

As shown in fig. 2, each coaxial connection unit 10 includes: a center contact 3 connected to the center conductor 51 of the coaxial cable 50 and contacting a center pin 72 of the connection unit 71 of the counterpart coaxial connector 70; a cylindrical housing 11 connected to the shield layer 53 and the outer conductor 54 of the coaxial cable 50 and fitted in contact with the outside of the outer contact 73 of the connection unit 71; an insulator 15 for supporting the cylindrical housing 11 coaxially with the center contact 3; and a sleeve 16.

The center contact 3 is formed by punching a strip-shaped conductive metal plate made of phosphor bronze or the like by press working and bending the plate in the shape shown in fig. 3 and 4, and is composed of: a central conductor connecting portion 4 which is connected to the central conductor 51 of the coaxial cable 50 by being pressed against the central conductor 51 at the rear; a cylindrical coupling portion 5 integrally connected to the front of the center conductor coupling portion 4; and a center contact portion 7 in which a pair of leaf springs are provided so as to protrude forward from the upper and lower positions of the front end of the coupling portion 5.

The coupling portion 5 is formed in a cylindrical shape surrounding the central axis of the central conductor 51 on the extension line of the central conductor 51, by folding both sides of a punched conductive metal plate into a semi-cylindrical shape with the center of the conductive metal plate as the front surface and the back surface facing each other, and abutting the end surfaces of both sides at a joint 5a of the back surface, similarly to the central conductor connecting portion 4. Thus, the coupling portion 5 is connected to the coaxial cylindrical center conductor connection portion 4 surrounding the center axis of the center conductor 51 in the forward extending direction of the center conductor 51, and is coaxially disposed at a predetermined distance from the coaxially disposed cylindrical housing 11 surrounding the center contact 3, and therefore, the characteristic impedance does not change drastically at these portions.

When punching a conductive metal plate, two sides of the conductive metal plate constituting a joint 5a are punched along the contour of a rectangular recess of a symmetrical shape, and a rectangular opening 6 is formed at the joint 5a of a connecting portion 5 formed by bending into a semi-cylindrical shape. That is, the opening 6 is not formed by punching the conductive metal plate, but the opening 6 is naturally formed in the step of punching the conductive metal plate and bending the conductive metal plate to form the connecting portion 5.

The distance between the contact portions at the front of the pair of plate springs constituting the center contact portion 7 is shorter than the outer diameter of the center pin 72 of the counterpart coaxial connector 70, and elastically contacts the center pin 72 inserted between the contact portions from the front. Therefore, the cylindrical coupling portion 5 is connected to the center conductor connection portion 4 on the rear front surface side and is in contact with the center contact portion 7 at the front upper and lower positions, and the high-frequency signal flows through the signal transmission path having the smallest creepage distance therebetween, and the opening 6 is not formed at a position that blocks the signal transmission path of the coupling portion 5, so that no new inductance is generated due to the formation of the opening 6.

The insulator 15 is integrally formed in a cylindrical shape surrounding and holding the entire center contact 3 by an insulating resin, and is opened at a front surface with an insertion hole 15a into which a center pin 72 of the counterpart coaxial connector 70 is inserted and which is brought into contact with the center contact portion 7.

As shown in fig. 2, the cylindrical housing 11 is formed in a cylindrical shape surrounding the entire insulator 15 with a conductive metal, and has an outer diameter slightly larger than that of the coaxial cable 5 to be connected in order to reduce the size of the coaxial connector 1 as a whole. The inner diameter of the front external contact portion 12 of the cylindrical housing 11 is slightly smaller than the outer diameter of the external contact 73, so that the external contact 73 of the counterpart coaxial connector 70 inserted from the front elastically contacts the inner wall surface, and the rear housing main body 14 is continued with the same inner diameter through the outer side surface of the insulator 15, so that the housing main body 14 forms a certain interval with the center contact 3 around the center axis of the center contact 3.

By setting the inner diameter of the cylindrical case 11 small, the distance between the cylindrical case 11 and the center contact 3 is close, and the characteristic impedance of the coaxial line is lowered at the position of the cylindrical case 11, but as shown in fig. 8, the distance between the inner wall surface of the cylindrical case 11 facing the back surface and the cylindrical center contact 3 is increased through the opening 6, and therefore, the capacitance C per unit length formed between the two at the position where the opening 6 is formed is increased₀The characteristic impedance is lowered and increased.

Fig. 9 is a graph comparing the measurement result of the time domain reflection of the coaxial connecting unit 10 constituted by the center contact 3 in which the opening 6 is not formed, which is shown by a solid line, with the measurement result of the time domain reflection of the coaxial connecting unit 10 constituted by the center contact 3 in which the opening 6 is formed, which is shown by a broken line, and shows that the characteristic impedance at the position is increased by forming the opening 6 to approach 50 Ω which is the characteristic impedance of the coaxial cable 5.

As described later, on the outer side surface of the housing main body 14, a recessed ring portion 17 for positioning the coaxial connection unit 10 in the front-rear direction on the insulating housing 2 is recessed around the axis of the cylinder. Further, the outer conductor connecting portion 13 at the rear of the cylindrical housing 11 is tapered so as to be inserted between the shield layer 53 and the outer conductor 54 of the coaxial cable 50 connected from the rear. After the outer conductor connecting portion 13 is inserted between the shield layer 53 and the outer conductor 54, the outer conductor 54 is fastened from the periphery by the cylindrical sleeve 16 formed of an insulating elastic body, whereby the cylindrical housing 11 is electrically connected to the shield layer 53 and the outer conductor 54 of the coaxial cable 50.

As described above, the center contact 3 connected to the center conductor 51 of the coaxial cable 50 and the cylindrical housing 11 connected to the outer conductor 54 are coaxially arranged around the center axis of the center contact 3 with the insulator 15 arranged therebetween, and are positioned with each other in the front-rear direction, and the coaxial connection unit 10 is assembled integrally.

As shown in fig. 2, four sets of coaxial connection units 10 connected to the ends of four coaxial cables 50 are mounted by inserting contact receiving holes 8 formed through the insulating housing 2 in the front-rear direction from the rear. In the insulating housing 2 of the coaxial connector 1, not-shown insertion holes through which the four contact receiving holes 8 are inserted from the front and rear surfaces, respectively, are provided, and not-shown positioning rods 9a through which the insertion holes are inserted are provided so as to protrude from positioning plates 9 attached to the front and rear surfaces, respectively.

After the four sets of coaxial connection units 10 are inserted into the corresponding contact receiving holes 8 from the rear, when the positioning rods are inserted into the insertion holes from the front and the rear, the positioning rods 9a are engaged with the recessed ring portions 17 on the outer side surface of the housing main body 14 in the contact receiving holes 8, and the coaxial connection units 10 are positioned in the front-rear direction on the insulating housing 2, whereby the four-pole coaxial connector 1 is assembled.

As shown in fig. 1, the counterpart coaxial connector 70 to be fitted into and connected to the coaxial connector 1 includes an insulating housing 74, a fitting recess 74a to be fitted into the insulating housing 2 is recessed in the insulating housing 74, and four sets of counterpart coaxial connecting units 71 including a center pin 72 and an outer contact 73 are protruded rearward from portions corresponding to the respective contact accommodating holes 8 in the fitting recess 74 a.

Thus, when the coaxial connector 1 and the mating coaxial connector 70 are fitted and connected, as shown in fig. 7, the outer contact 73 of the mating coaxial connecting unit 71 is in contact with the inner wall surface of the cylindrical housing 11 of the coaxial connecting unit 10, and the center pin 72 is inserted through the insertion hole 15a of the insulator 15 and elastically contacts the center contact portion 7 of the center contact 3.

Since the center pin 72 of the mating coaxial connector 70 elastically contacts the center contact portion 7 in front of the connection portion 5 of the center contact 3 having the opening 6 formed therein, the opening 6 is formed, and therefore, the reliability of connection with the mating coaxial connector 70 is not impaired. Further, even if the opening 6 is formed in the center contact 3, the periphery around the center axis thereof is covered with the housing main body 14 of the cylindrical housing 11, and therefore, it can be completely shielded. Therefore, even if a plurality of coaxial connection units 10 are provided in parallel on the insulating housing 2 as in the present embodiment, the high-frequency signal flowing through the center contact 3 does not leak to the signal transmission path of another coaxial connection unit 10 and crosstalk occurs.

In the above-described embodiment, the multipolar coaxial connector 1 in which the plural sets of coaxial connection units 10 are arranged in the single insulating housing 2 is used, but a coaxial connector in which only one set of coaxial connection units 10 is arranged may be used.

The contour shape of the opening 6 formed in the center contact 3 is not limited to the above-described rectangular shape, and may be formed in various shapes, and the position where the opening 6 is formed may be formed at any position of the connecting portion 5 between the center contact portion 7 and the center conductor connecting portion 4 in front.

The coupling portion 5 is formed in a cylindrical shape around the center axis of the center contact 3 connected to the center axis of the coaxial cable 50, and may be formed in other shapes such as a square cylinder instead of a cylindrical shape.

Industrial applicability

The present invention is applied to a coaxial connector which is connected to the end of a coaxial line and is miniaturized.