JPH09101105A - Connection method for winding end of coil and contact type displacement sensor using the coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely and compactly connect a winding end of ultra small coil using an extremely thin winding to a lead. SOLUTION: An excitation coil 12 and detection coils 13, 14 composing a differential type transformer are arranged inside a housing. At a conduction line relaying part 60 connecting end of winding of each coil 12-14 and leads 63-66 to each other, five pieces of metal relay members 70 of a cylindrical shape having open opposed ends are provided. After the end 13b, 14b of winding is inserted from the opening on the side of one end of the member 70 to the opening on the side of the other end thereof in order to connect the intermediate connection part 50 of the detection coils 13, 14, solder fused is supplied to remove the insulation coating of winding ends 13b, 14b with the heat, and the ends are simultaneously soldered inside the member 70. An unnecessary portion on the side of end of each winding end 13b, 14b is pulled from the other end of the member 70 and is thereby cut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting winding end portions of a coil in an electronic device incorporating a small coil and a contact type displacement sensor using this coil.

[0002]

2. Description of the Related Art A displacement sensor using a differential transformer has been conventionally known. For example, the conventional displacement sensor 1 shown in FIG. 11 has a rod-shaped core 3 inside a cylindrical housing 2.
Is provided movably in the axial direction, a plunger 4 is provided on one end side of the core 3, and the plunger 4 is provided by a spring 5.
Is urged toward the measuring object W. An exciting coil (primary coil) that constitutes a differential transformer is provided outside the core 3.
6 and a pair of detection coils (secondary coils) 7 and 8 are arranged. In the displacement sensor 1 described above, when a primary AC voltage is applied to the excitation coil 6, the generated magnetic flux links the detection coils 7 and 8. By doing so, the difference between the electromotive forces generated in the detection coils 7 and 8 can be taken out as the output voltage (secondary voltage). If the position of the core 3 is at the neutral point with respect to the detection coils 7 and 8, the output voltage is almost zero, but if the position of the core 3 is displaced from the neutral point, the output voltage is changed according to the displacement amount. It has a linear output characteristic such as a large value. Therefore, if the relationship between the output voltage and the displacement amount of the core 3 is obtained in advance, the position of the core 3, that is, the displacement amount of the plunger 4 can be known based on the detected output voltage.

[0003]

In the above conventional contact type displacement sensor 1, it is required to downsize the housing 2 and the coils 6, 7 and 8 when the object to be measured is small. Housing 2 with a diameter of several mm
It is desirable to have ultra-small coils 6, 7, and 8 that can be accommodated in the. In that case, the windings of the coils 6, 7 and 8 will be extremely thin, so if you do not take special measures in the lead wire relay section for connecting to external equipment, the winding end will be cut or damaged. I have something to do. Especially when soldering an extremely fine wire of 50 μm or less to an external lead wire via a terminal board or the like, the end of the winding is easily touched by heat or flowing solder or a soldering iron during soldering. It cannot be soldered to a desired position, and it is difficult to process the winding end portion after soldering.

Moreover, in order to make the displacement sensor thinner, the outer diameter of the whole conductor relay portion for connecting the winding end portion and the lead wire is restricted, so that the conductor relay with the lead wire is restricted. The department is even more difficult. For this reason, in a micro contact displacement sensor or the like, the conductive wire relay portion between the coil winding end portion and the external lead wire is likely to be a weak point, and it is an obstacle to reducing the outer diameter of the housing.

Therefore, the object of the present invention is to connect the lead wire without damage to the end portion of the extra fine coil winding, and to make the coil of the coil effective for downsizing the conductor relay section. An object of the present invention is to provide an end connection method and a contact displacement sensor using a coil.

[0006]

SUMMARY OF THE INVENTION A winding end connecting method according to claim 1 of the present invention, which has been developed to achieve the above-mentioned object, provides a winding end of a coil housed in a housing. A connection method for connecting to a lead wire, wherein the end portion of the winding is inserted into an opening on one end side of a metal cylindrical relay member having both ends opened, and the end portion of the winding is connected to the end portion of the relay member. The molten solder is supplied to the relay member and the winding end portion while being pulled out from the opening on the other end side, the insulating coating on the winding end portion is removed by the heat, and the winding end portion is soldered to the relay member. After attaching, the excess tip side portion of the winding end is cut out from the other end side opening of the relay member, and then the lead wire is inserted from the other end side opening and the lead wire is fixed to the relay member. By using this relay member, The characterized by interconnected.

A winding end connecting method according to a second aspect of the present invention is applied to a contact type displacement sensor using a differential transformer, both ends of which are open, and one end side opening extends midway in the axial direction. A plurality of metal-made cylindrical relay members having slits are arranged in the vicinity of the coils, and one end of the relay member is provided at the input terminal portion and the output terminal portion for connecting each coil and the lead wire. The end of the coil winding is inserted into the side opening and the end of the winding is pulled out from the other end side opening of the relay member, and molten solder is supplied to the relay member and the winding end. The heat removes the insulating coating on the winding ends and the winding ends are soldered to the relay member.The excess tip end of the winding end is then cut off from the opening on the other end of the relay member. , And then the opening on the other end side The lead wire is inserted and fixed to the relay member, and at the intermediate connection portion connecting the pair of detection coils to each other, the end portion of the winding of each detection coil is inserted from one end side opening of the relay member. Further, it is characterized in that molten solder is supplied to the winding end portions and the relay member, and the insulating film on the winding end portions is removed by the heat to solder the winding end portions to the relay member.

According to a third aspect of the contact displacement sensor of the present invention, a cylindrical housing, an exciting coil housed inside the housing so that a coil axis extends along the axial direction of the housing, and the exciting coil is provided. A pair of detection coils which are adjacent to both ends of the coil and are housed in the housing so that each coil axis extends along the axial direction of the housing, and penetrate the center of each coil to move in the axial direction of the housing. A pair of detection coils, each of which includes a freely provided core, a plunger connected to the core and having a tip end side protruding to the outside of the housing, and an elastic member for urging the plunger in a direction to push the plunger out of the housing. One of the coils has a cylindrical shape with both ends open in the vicinity of the end face, and extends along the axial direction from the one end side opening to the other end side. Five relay members made of metal having slits are provided, and both ends of the winding of the exciting coil are inserted from one end side opening of each of the first relay member and the second relay member toward the other end side opening. Moreover, the input lead wire inserted from the other end opening side of the relay member is soldered to the relay member, and the input lead wire is fixed to the relay member. The relay member and the fourth relay member are inserted from one end side opening toward the other end side opening and soldered to the relay member, and the output lead wire inserted from the other end side opening of the relay member is connected to the relay member. Fixed to
In the intermediate connection part that connects the pair of detection coils to each other, the winding end part of each detection coil is inserted from one end side opening of the fifth relay member and soldered, and the five relay members are connected to the housing. The relay members are arranged so as to be parallel to each other in the circumferential direction of the electrically insulating base member inside.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. The contact type displacement sensor 10 shown in FIG. 4 includes a cylindrical housing 11 having both ends open, a hollow exciting coil (primary coil) 12 and a pair of detecting coils (secondary coils) 13 and 14 housed in the housing 11. , A core 16 made of a cylindrical permalloy or the like that passes through the inside of each of the coils 12 to 14, and a plunger 17 connected to the core 16.
And so on. As shown in an enlarged manner in FIG. 5, an inner cylinder 20 made of an electrically insulating material is provided on the inner peripheral surfaces of the coils 12 to 14. A washer 21 is provided between the coils 12 to 14.

The housing 11 has a cylindrical housing body 11a having an outer diameter of about several mm (for example, 2 to 3 mm) and a stopper 26 fixed to the tip of the housing body 11a.
And so on. The material of the housing body 11a is a non-magnetic electric insulating material or a metal having a low magnetic permeability such as stainless steel.

The plunger 17 is provided so as to be movable in the axial direction of the housing 11. This plunger 17
Includes a plunger body 17a made of a low-permeability material such as stainless steel, and a tip member 31 functioning as a contact. The plunger main body 17a has a large diameter portion 32 located at an intermediate portion in the axial direction thereof and small diameter portions 33 and 34 located at both ends of the large diameter portion 32, and at the tip of the small diameter portion 34 on the lower side in the drawing. A tip member 31 made of wear-resistant metal is attached.

An intermediate spacer 40 is fixed to the axially intermediate portion of the housing body 11a. An elastic member 41 such as a compression coil spring is provided between the intermediate spacer 40 and the large-diameter portion 32, and the elastic member 41 urges the plunger 17 in a direction projecting from the housing 11. This plunger 17 has a large diameter portion 32.
The maximum amount of protrusion from the housing 11 is regulated by abutting the lower end surface 32 a of the stopper against the stopper 26.

The core 16 is provided on the upper end side of the plunger body 17a.
A terminal small-diameter portion 45 having the same outer diameter as that of the core 16 is formed, and the core 16 is connected to the plunger body 17a by a tubular connecting member 46 fitted in the terminal small-diameter portion 45. Therefore, the core 16 can move integrally with the plunger 17.

As shown in FIG. 1, the coil unit 15 includes detection coils 13, 1 on both ends of the exciting coil 12 in the axial direction.
By arranging four, a three-stage differential transformer is constructed. The wire diameters and lengths of the windings used for the coils 12, 13, and 14 are substantially the same as each other, and each of the windings is made of a copper wire having a wire diameter of 50 μm or less and electrically insulated with urethane resin or the like. It is an ultrafine coated wire covered with the coating of.

As shown in FIG. 9, the detection coils 13 and 14 are
Are connected in series with opposite polarities in the intermediate connection portion 50, a primary AC voltage Ep is applied to the input terminal portions 51 and 52 of the exciting coil 12, and the output voltage (secondary voltage) Es is applied to the output terminal portions 53 and 54. Is obtained. In this type of differential transformer, when the alternating voltage Ep is applied to the exciting coil 12, the magnetic flux is detected by the detecting coils 13, 1.
Since it interlinks with 4, the difference Es between the electromotive forces E _S1 and E _S2 generated in the detection coils 13 and 14 can be taken out as a secondary voltage. The secondary voltage Es is substantially zero when the position of the core 16 is at the neutral point with respect to the detection coils 13 and 14, but when the core 16 is displaced from the neutral point, the value of Es is changed according to the displacement amount. It has a linear output characteristic such as a large value. Therefore, by detecting the relationship between the secondary voltage Es and the displacement amount of the core 16 in advance, the detected secondary voltage Es
The position of the core 16, that is, the amount of displacement of the plunger 17 can be known based on the above.

A conductor relay portion 60 is provided near the end surface of the detection coil 14. In this conductor relay unit 60,
The ends 12 a and 12 b of the winding of the exciting coil 12 are connected to the input lead wires 63 and 52 via the input terminal parts 51 and 52, respectively.
Is connected to the first detection coil 13
One end portion 13a of the winding of the second detection coil 14 is connected to the output lead wire 65 via the output terminal portion 53.
One end portion 14a of the winding is connected to the output lead wire 66 via the output terminal portion 54. Each lead wire 63 to 6
6 is a bundled cable 67 that is drawn out of the housing 11. The other ends 13b and 14b of the windings of the detection coils 13 and 14 are connected to each other at the intermediate connection portion 50.

The input terminal portions 51 and 52 and the output terminal portion 53,
54 has a common structure, and in FIG.
As shown by a typical example, the relay member 70 is used to
2a and the lead wire 63 are connected. On the other hand, as shown in FIG.
0 is used to connect the ends 13b and 14b of the windings to each other.

The terminal portion 51 shown in FIG. 2 is shown in FIGS.
The end 12a of the winding and the lead wire 63 are connected through the step shown in (E). The relay member 70 is a cylindrical thin tube made of a conductive material such as brass and having both ends opened, for example, an outer diameter of 0.6 mm and a length of about 3 mm.
In this relay member 70, one end side opening 71 to the other end side opening 7
The slit 73 extending toward 2 is formed up to the intermediate portion in the axial direction of the relay member 70. The relay member 70 is fixed to a base member 75 (shown in FIGS. 5 and 8) made of an electrically insulating material. As shown in FIG. 8, the base member 7
5, concave portions 76 into which five relay members 70 are fitted are formed at equal pitch P in the circumferential direction of the base member 75. At the center of the base member 75, a center hole 77 is formed through which the core 16 is movably inserted.

As shown in FIG. 6A, the end portion 12a of the winding wire
Is inserted from one end side opening 71 of the relay member 70, and the end 12
After completely drawing a through the opening 72 on the other end side,
As shown in (B), solder 80 is applied from the outside of the slit 73.
Is supplied and heated using a trowel 81 or the like. By doing so, the melted solder 80 enters the inside of the relay member 70, and the insulating coating on the winding end 12a is removed by heat, so that the solder 80 can be removed by the solder 80 as shown in FIG. 6C. The portion 12a is fixed to the relay member 70 and is electrically connected. At the time of this soldering, the winding end 12a is completely inserted into the cylindrical relay member 70, so that the winding end 12a can be prevented from moving in an unspecified direction during soldering. The winding end 12a can be reliably soldered.

Then, as shown in FIG.
The excess portion 12c of the winding is cut off and removed by pulling the portion 12c on the tip end side of the winding end portion that comes out of the. After that, as shown in FIG. 6 (E), the solder coated lead wire 63 is inserted from the other end side opening 72 of the relay member 70 and heated to a temperature at which the solder previously attached to the lead wire 63 is melted. After cooling,
The lead wire 63 is fixed to the relay member 70 and is electrically connected. The lead wire 63 is covered with an electrically insulating jacket 85.

The relay member 70 thus soldered is fitted into the concave portion 76 of the base member 75, and is filled with the electrically insulating resin 87 to be fixed to the base member 75. As a means for fixing the lead wire 63 to the relay member 70, for example, after inserting the lead wire 63 into the relay member 70, the relay member 70 is caulked and deformed to fix the lead wire 63 to the relay member 70. Good. The terminal portions 52, 53, 54 other than the above are also soldered by the same method as the terminal portion 51.

The intermediate connection portion 50 is connected to the ends 13b and 14b of the winding through the steps shown in FIGS. 7 (A) to 7 (E). The relay member 70 used here is the terminal portion 51.
Is the same as that used for. 2 as shown in FIG.
After inserting the end portions 13b and 14b of the book winding from the one end side opening 71 of the relay member 70 and completely pulling out the end portions 13b and 14b from the other end side opening 72, as shown in FIG. , Solder 80 is supplied from the outside of the slit 73, and the soldering iron 8
Heat with 1 or the like.

By doing so, the molten solder 80 enters the inside of the relay member 70 and the winding end portion 13
The insulating coatings b and 14b are removed by heat. Therefore, as shown in FIG. 7C, the winding ends 13b and 14b are fixed to the relay member 70 by the solder 80, and the both are electrically connected. At the time of this soldering, the winding end portions 13b and 14b are completely inserted into the cylindrical relay member 70.
3b and 14b can be prevented from moving in unspecified directions, and the winding end portions 13b and 14b can be reliably soldered.

Then, as shown in FIG.
Pull the tip side portions 13c and 14c of 3b and 14b,
Extra portions 13c, 14c of the winding wire coming out of the solder 80
By removing the, the intermediate wire connection portion 50 having the two winding end portions 13b and 14b fixed thereto is obtained as shown in FIG. 7 (E). The relay member 70 is used as the recess 7 of the base member 75.
6 and is fixed to the base member 75 by filling with an electrically insulating resin 87.

In the above embodiment, the two winding end portions 13 are
Since only one relay member 70 is used to connect b and 14b to each other, a total of five winding members are used to perform connection processing for a total of six winding ends drawn from the three coils 12, 13, and 14. It is in time with the relay member 70 of. Before this embodiment was proposed, the winding end portion 13b,
14b are soldered to separate relay members 70, and these two relay members 70 are connected to each other by U-shaped jumper wires. Therefore, it is necessary to arrange a total of six relay members 70 in the circumferential direction of the base member 75. was there. On the other hand, in the present embodiment, as shown in FIG. 8, it is only necessary to arrange a total of five relay members 70 in the circumferential direction of the base member 75, and as compared with the case where six relay members 70 are used, the relay members 70 are relayed. If the arrangement pitch P of the members 70 is the same (1 mm is an example of P), the outer diameter of the base member 75 (that is, the conductor relay portion 60).
It was possible to reduce the outer diameter of the product by about 11.5%.

FIG. 10 shows an example of an apparatus for measuring the shape, size, etc. of the measuring object W using the displacement sensor 10. In this case, the plurality of displacement sensors 10 are attached to the mounting substrate 9
0, the plunger 17 of each sensor 10 is brought into contact with the measuring object W, and the plunger 17 is displaced toward the housing 11. By doing this, since a detection signal corresponding to the relative distance from each sensor 10 to the measurement object W is output from each sensor 10, each detection signal is processed by the arithmetic processing unit (controller) 91 using a microcomputer or the like. By doing so, the shape, size, and the like of the measurement object W can be known.

[0027]

According to the present invention, in an electronic device or the like in which a micro coil is housed in a thin housing having an outer diameter of, for example, about several mm, the winding end of the coil and the external lead wire are connected by soldering. It can be performed without any problems, and ultrafine windings can be reliably connected to lead wires without causing problems such as damage or disconnection. Moreover, the winding relay portion can be compactly housed inside the housing that houses the coil.

In the coil constituting the differential transformer according to the second aspect of the invention, in the intermediate connection portion between the two detection coils, two winding end portions drawn out from each coil are combined into one. Since the connection can be made using only the relay member, the total number of the relay members is 5 and the outer diameter of the conductor wire relay portion can be further reduced, which contributes to further reduction in the diameter of the housing. it can.

In the contact type displacement sensor according to the third aspect, a total of 6 winding ends drawn out from one exciting coil and two detecting coils are used by using five relay members. Predetermined wiring can be done, and all relay members are arranged parallel to each other along the axial direction of the sensor housing, so all relay members can be accommodated inside the thin housing without any problems, and input The outer diameter of the entire conductor relay portion including the terminal portion, the output terminal portion, and the intermediate connection portion can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a coil unit of a contact displacement sensor according to an embodiment of the present invention.

FIG. 2 is a side view of a connecting portion between a winding end portion and a lead wire in the coil unit shown in FIG.

FIG. 3 is a side view of an intermediate connection portion of the coil unit shown in FIG.

FIG. 4 is an overall vertical cross-sectional view of a contact type displacement sensor incorporating the coil unit shown in FIG.

5 is an enlarged cross-sectional view of a part of the displacement sensor shown in FIG.

6 is a cross-sectional view showing a step of soldering the connection portion shown in FIG.

7 is a cross-sectional view showing a step of soldering the intermediate wire connection portion shown in FIG.

8 is a sectional view taken along line VIII-VIII in FIG.

9 is a circuit diagram of the displacement sensor shown in FIG.

10 is a cross-sectional view of a measuring device using the displacement sensor shown in FIG.

FIG. 11 is a sectional view of a conventional contact type displacement sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Displacement sensor 11 ... Housing 12 ... Excitation coil 12a, 12b ... Winding end 13 ... 1st detection coil 13a, 13b ... Winding end 14 ... Second detection coil 14a, 14b ... Winding End portion 16 ... Core 17 ... Plunger 41 ... Elastic member 50 ... Intermediate connection portion 51, 52 ... Input terminal portion 53, 54 ... Output terminal portion 60 ... Conductor relay portion 63, 64, 65, 66 ... Lead wire 70 ... Relay member 73 ... Slit 80 ... Solder

Claims (3)

[Claims] 1. A connection method for connecting an end portion of a coil of a coil housed in a housing to a lead wire, wherein the winding is provided at an opening on one end side of a metallic cylindrical relay member having both ends opened. Insert the end of the wire and pull out this winding end from the other end side opening of the relay member, supply molten solder to this relay member and winding end, and heat the winding end After removing the insulating coating on the part and soldering the winding end to the relay member, the excess tip side part of the winding end is cut off from the opening on the other end side of the relay member, and then the other end. By inserting a lead wire from the side opening and fixing the lead wire to the relay member, the winding end portion and the lead wire are connected to each other through the relay member, and the winding end portion of the coil is characterized. Connection method. 2. A connection method for connecting an exciting coil for a differential transformer housed in a housing and an end of each winding of a pair of detection coils, wherein both ends are open and an opening is formed at one end side in an axial direction. In the input terminal section and the output terminal section for connecting the coils to the lead wires, a plurality of metal cylindrical relay members each having a slit extending halfway are arranged in the vicinity of the coil. The end portion of the coil winding is inserted into the opening on one end side of the relay member, and the end portion of the winding is pulled out from the opening on the other end side of the relay member. And the heat is applied to remove the insulating coating on the winding end and the winding end is soldered to the relay member. Cut off from the opening, then A lead wire is inserted from the opening on the other end side and fixed to the relay member, and in the intermediate connection portion connecting the pair of detection coils to each other, the end portion of the winding of each detection coil is connected to one relay member. Inserting from one end side opening and supplying molten solder to these winding ends and relay members, and removing the insulating coating on the winding ends by the heat to solder these winding ends to the relay members. A method of connecting winding end portions of a coil, characterized by: 3. A cylindrical housing, an exciting coil housed inside the housing so that a coil axis extends along the axial direction of the housing, and adjacent to both ends of the exciting coil in the axial direction of the housing. A pair of detection coils housed in the housing so that each coil axis extends, a core pierced through the center of each coil and movable in the axial direction of the housing, and connected to the core. A plunger having a tip end protruding to the outside of the housing, and an elastic member for urging the plunger in a direction to push the plunger out of the housing are provided, and both ends are provided in the vicinity of an end surface of one of the pair of detection coils. Five relay members made of metal having a cylindrical shape having an opening and having slits along the axial direction from the one end side opening toward the other end side are provided, The both ends of the winding of the exciting coil are connected to the first relay member and the second relay member.
Each relay member is inserted from one end side opening toward the other end side opening and soldered to the relay member, and the input lead wire inserted from the other end opening side of this relay member is fixed to the relay member. , One end of each of the windings of the pair of detection coils is inserted from one end side opening of the third relay member and the fourth relay member toward the other end side opening, and is soldered to the relay member,
Further, the output lead wire inserted from the other end side opening of the relay member is fixed to the relay member, and in the intermediate connection portion connecting the pair of detection coils to each other, the winding end portion of each detection coil is connected to the fifth end portion. The relay members are inserted from one end side opening and soldered, and the five relay members are arranged inside the housing so that the relay members are parallel to each other in the circumferential direction of the electrically insulating base member. Characteristic contact type displacement sensor.