JPH11233227A - Method and structure of jointing terminal with lead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a structure of jointing a terminal with a lead improving jointing strength of the terminal with the lead. SOLUTION: A connector part 14 of a terminal 10 is embossed with an umbo 15, an aperture 16a is formed in the tip part of a lead 16, the aperture 16a is locked onto the umbo 15 to caulk it, thus the terminal 10 is jointed with the lead 16. Consequently, jointing strength of the terminal 10 with the lead 16 can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining a terminal and a lead used for electrical connection of various devices and a joining structure thereof.

[0002]

2. Description of the Related Art Conventionally, as a method of joining a terminal and a lead, there is a method of crimping by crimping by inserting a lead into a terminal and partially deforming the terminal by applying pressure from outside the terminal. For example, JP-A-59-138080
According to FIG. 29, as shown in FIG. 29, the terminal 1 connected to the strip-shaped metal strip 3 sequentially goes through each step as shown by the arrow A. First, the conductive cable 2 is inserted into the terminal 1, and the insulating sheath 5 of the conductive cable 2 is attached to the main body 1 a of the terminal 1.
And a plastic material 6 comprising a cylindrical portion and a frusto-conical portion formed integrally with the cylindrical portion.
To the conductive cable 2 at the main part 1a of the terminal 1.
The conductor 4 is crimped and tightened to join the conductive cable 2 and the terminal 1. However, in this method, there is a problem that the conductive cable 2 has a low strength against pulling and easily comes off from the terminal 1. In the case of a small-diameter tube-shaped terminal, it is considered that strength is disadvantageous.

[0003] Next, there is a method of joining a terminal and a lead by soldering. However, disadvantages in this case are that uniform joining cannot be performed by soldering, and cracks (cracks) of the solder due to aging occur. In addition, there is a problem with insufficient bonding strength and durability of bonding strength.

[0004] In addition, there are joining methods such as arc welding, laser welding, and spot welding. In this case, depending on the shape and size of the joining portion and the material of the joining base material,
In some cases, welding cannot be applied to the connection between a tubular terminal and a lead.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for joining a terminal and a lead, which can improve the joining strength between the terminal and the lead, and a joint structure thereof. And

[0006]

According to the present invention, a projection is formed by embossing a connector portion of a terminal or a tip portion of a lead, and an opening is formed in a tip portion of the lead or a connector portion of a terminal. The opening is engaged with the projection formed by embossing, and the projection is caulked to join the terminal and the lead. Thereby, the bonding strength between the terminal and the lead can be improved.

[0007] Alternatively, in a joint structure of a terminal and a lead comprising a terminal comprising a cylindrical portion and a connector portion integrally formed at one end of the cylindrical portion and a lead fixed to the connector portion, An opening is formed in one of the portion and the tip of the lead, and a projection is formed in the other, and the projection is engaged with the opening and is fixed in phase by caulking. The problem is solved by a bonding structure between the terminal and the lead.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

As a first embodiment of the present invention, a method of joining a terminal and a lead by a progressive processing method will be described. FIG.
5 is a flowchart showing a bonding step between a terminal and a lead. Referring to FIGS. 2, 3 and 4, terminal 10 is formed in step a.
And the processing that the lead 16 receives in step b will be described. 2A shows a front view of the terminal 10 together with a side view, and FIG. 2B shows a rear view of A in the [2]-[2] line direction. First, as a first step, the metal terminal 10 is cut out into a shape as shown in FIG. 2 by metal pressing. The shape of the band 11 is the same as that of the band 11, and the protrusion 12 protrudes from the band 11 in one direction and is formed integrally with the band 11.
And a rectangular terminal forming portion 13 formed integrally with the protruding portion 12 and having a width larger than that of the protruding portion 12.
The protruding portion is formed integrally with the terminal forming portion 13 and includes a connector portion 14 having a larger width than the protruding portion 12 but a smaller width than the terminal forming portion 13. The band 11 is one terminal 1
Although it is cut off for zero, it is continuous, and the terminal forming portion 13 and the connector portion 14 are connected to the band portion 11 at equal pitches by the projecting portions 12. The processing of the terminal 10 is advanced by intermittently feeding the respective steps in the direction indicated by the arrow C by the holes h while the band portions 11 are connected. (A so-called progressive die type). Hereinafter, the same applies to FIGS. 3 to 6. Note that the hole h and the protrusion 1 shown by a broken line in FIG.
2 is omitted in FIGS. 3 to 6.

Next, as shown in FIG. 3, in a second stage, the terminal 10 is wound into a rectangular terminal forming portion 13 and processed into a split ring shape, and the connector portion 14 is formed in a side view of FIG. 3A. An inclined step is formed as shown. This is formed at the same time as embossing, for example.

Next, in a third stage shown in FIG.
The protrusion 15 is formed on the upper surface of the horizontal portion 14a of the connector portion 14 by embossing.

On the other hand, in the step b shown in the flow chart of FIG. 1, the entire length of the strip-shaped lead 16 is first determined as shown in FIG. The other end of the lead 16 is not shown in FIG. 3), cut into a predetermined length, and then fitted to the protruding portion 15 formed by embossing at the tip of the lead 16 as shown in FIG. The opening 16a is formed in such a size as to form the opening 16a. Further, the lead 16 is not of the progressive type, but may be determined in a single shot in advance, and the lead 16 having the opening 16a formed at the tip may be sent to the following step c.

Next, the terminal 10 and the lead 16 which have been processed as described above in the steps a and b respectively proceed to the step c. This step c is shown in FIG. Here, the opening 16 a of the lead 16 is engaged with the projection 15 formed on the connector 14 of the terminal 10.

The opening 16a of the lead 16 is connected to the terminal 1
After engaging with the protrusion 15 of FIG. 1, the head 15a of the protrusion 15 protruding above the lead 16 as shown in FIG. Then, the lead 16 and the terminal 10 are securely joined. Then, as the final step e, the protrusion 1 shown in FIG.
The line 10 is cut at the portion of the line L to complete the terminal 10 to which the lead 16 is attached. (See side view in FIG. 6A).

Although the processing of the terminal 10 has been described as a progressive type, it can be performed in a single shot. In this case, a protrusion 16 is formed by embossing the connector portion 14 on the terminal 10 having the terminal forming portion 13 already processed into a cylindrical shape, and the lead 16 having the opening 16a formed at the tip is connected to the opening 16a. The projection 16a is engaged with the projection 15, and the projection 15 is swaged.

By joining the lead 16 and the terminal 10 as described above, the joining strength can be improved. In particular, the tensile strength is significantly improved. Further, there is no deterioration due to aging such as joining by soldering, and the durability is improved. In addition, uniform joining is possible by press working, and there is no problem in press working with a general metal material. Therefore, the material of the terminal 10 and the lead 16 is limited as in welding. Absent. In addition, high productivity, which is an advantage of press working, can be expected.

The bonding method of the present invention, including the embodiments described below, can be applied without being limited to the size of the terminals and leads, so that particularly small batteries (for example, lithium-ion batteries, Polymer secondary battery, etc.)
This is effective for joining a plate-shaped electrode (corresponding to a lead) with a tube-shaped terminal. Even if plugs of other electric devices are frequently inserted and removed from the terminals of the battery, the strength and durability of the joint are significantly improved as compared with the related art, so that such use can be sufficiently endured.

Next, a second embodiment of the present invention, which is a one-shot processing type, will be described with reference to FIGS. As shown in FIGS. 7, 8 and 9, the horizontal portion 21 a of the connector portion 21 of the terminal 20 is formed with a projection 2 by embossing.
2 are formed, and a pair of ribs 17a and 17b are further formed on both sides of the protrusion 22 to join the leads 23 in a later step.
Parallel to the length direction (shown in FIG. 10) and FIG.
The lead 2 is provided between the pair of ribs 17a and 17b as shown by
3 is formed by press working so that it can be exactly contained. Then, as shown in FIG.
3a is engaged with the projection 22 so that the head 22
The terminal 20 and the lead 23 are joined by swaging a. The above-described rib forming process can also be performed by a progressive type process.

As described above, in the second embodiment of the present invention, by performing the rib forming process parallel to the length direction of the lead 23, the rotation of the lead 23 around the projection 22 can be restricted. .

Next, a third embodiment of the present invention will be described with reference to FIGS. 12 and 13
As shown in FIG. 14, the direction of the lead 23 (shown in FIG. 15) is perpendicular to the length direction of the lead 23 (shown in FIG. 15) by changing the direction by 90 ° with respect to the second embodiment. A pair of ribs 18a and 18b are formed on both sides of the projection 26 by press working.

Then, as shown in FIG. 16, the opening 23a of the lead 23 is engaged with the projection 26 of the terminal 24, and the head 26a of the projection 26 is swaged. FIG. 17 is an enlarged view of the joint portion between the lead 23 and the terminal 24 in FIG. 16. When this caulking is performed, the ribs 18a and 18b are connected as shown in FIG.
However, it is difficult for the lead 23 to enter. Thereby, the strength of the joint between the lead 23 and the terminal 24 is further increased. The rib forming process in the third embodiment described above can be performed by either a progressive type process or a single-shot type process.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 19 is a front view of the terminal 30 in the present embodiment, and FIG.
9 is a partially cutaway sectional view taken along line [18]-[18] in FIG. The terminal 30 includes a first cylindrical portion 31 having a large diameter,
A frustoconical portion 32 integrally formed at one end of the first cylindrical portion 31 and a second cylindrical portion integrally formed at one end of the frustoconical portion 32 and having a smaller diameter than the first cylindrical portion 31. 33. A pair of slits 36a and 36b extending from the outer end of the second cylindrical portion 33 to the middle of the truncated conical portion 32 along the axial direction are formed so as to face each other in the radial direction. An opening 34 is formed on the upper surface side of the peripheral wall of the second cylindrical portion 33, and a tapered surface 35 is formed on an edge of the opening 34.

The terminal 30 constructed as described above
Next, as shown in FIG. 20, a lead 37 having an opening 37a at the tip is inserted. At this time, the opening 34 formed in the second cylindrical portion 33 and the opening 37 formed in the lead 37
The lead 37 is inserted so that a is aligned vertically.

As a next step, as shown in FIG. 21, the opening 37a of the lead 37 is inserted through the peripheral wall of the second cylindrical portion 33 facing the opening 34 formed in the second cylindrical portion 33. Embossing is performed to form a projection 38 so as to project from the opening 34 of the two cylindrical portion 33. At this time,
Embossing is performed by pressing the second cylindrical portion 33 made of metal from the upper side and the lower side, and extends from the outer end of the second cylindrical portion 33 to the middle of the truncated conical portion 32 along the axial direction. Due to the pair of slits 36a and 36b, the second cylindrical portion 33 made of metal can be easily crushed, and the embossing as described above can be performed.

Next, the terminal 30 and the lead 37 are joined by caulking the head 38a of the projection 38. . FIG. 22 is a plan view of the joined terminal 30 and lead 37, and FIG. 23 is a sectional view taken along the line [23]-[23] in FIG. As shown in FIG. 23, the second cylindrical portion 33
Since the tapered surface 35 is formed at the edge of the opening 34, when the head 38a of the protrusion 38 is swaged, the protrusion 38
And the second cylindrical portion 33 can have a stronger fastening force.

In addition to the step of caulking the head 38a of the projection 38, the projection 37 projects inward in the direction perpendicular to the longitudinal direction of the lead 37 to the inside of the second cylindrical portion 33 on both sides of the projection 38. So that a pair of upper and lower ribs 39a, 39b and 4
0a and 40b are formed by press working. At the time of caulking, the ribs 39a, 39b and 40a, 40b bite into the upper and lower surfaces of the lead 37, and the terminal 30 and the lead 37
To increase the bonding strength.

Further, a pair of slits 41a and 41b are formed in the upper part of the peripheral wall of the first cylindrical portion 31 of the terminal 30 in parallel with the length direction of the lead 37, and the slits 41a and 41b are formed.
A pair of slits 42a and 42b are also formed at the lower part of the peripheral wall of the first cylindrical portion 31 so as to face the first cylindrical portion 41b. Then, a curved portion 43a is formed by curving the peripheral wall portion between the slits 41a and 41b formed on the upper portion of the peripheral wall portion of the first cylindrical portion 31 so as to protrude radially inward. Similarly, the curved portion 43b is formed by curving the peripheral wall portion between the slits 42a and 42b formed at the lower portion of the peripheral wall portion so as to protrude radially inward. (Shown in FIG. 23). Thereby, the plug of another electric device inserted into the first cylindrical portion 31 of the terminal 30 elastically contacts the curved portions 43a and 43b, and an effect of preventing the plug from coming off from the terminal 30 is obtained.

The joining process of the terminal 30 and the lead 37 in the above-described fourth embodiment of the present invention is performed in a one-shot processing mode. The bonding method according to the fourth embodiment can significantly increase the bonding strength as compared with the first, second, and third embodiments.

Next, a description will be given of a fifth embodiment of the present invention, which is performed in a one-shot processing mode. As shown in FIG. 28, two projections 47 and 48 are formed by embossing the horizontal portion 49a of the connector 49 of the terminal 45, and the projections 47 and 48 The two openings 46a, 4
6b is formed. Then, the openings 46a, 4
The protrusions 47 and 48 are swaged by engaging the protrusions 6b with the protrusions 47 and 48, respectively. As a result, the terminal 45 and the lead 46 are joined at two places, and the joining strength can be further increased.

Next, a description will be given of a sixth embodiment of the present invention which is performed in a single-shot type processing mode. As shown in FIGS. 24 and 25, the first cylindrical portion 55, the truncated conical portion 56, and the first cylindrical portion 55 having a smaller diameter than the first cylindrical portion 55 by the same processing steps as the bonding method shown in the fourth embodiment. The lead 51 having two openings 57 and 58 formed in the second cylindrical part 52 and two openings 51 a and 51 b formed in the tip part of the terminal 50 composed of the two cylindrical parts 52 is connected to the second cylindrical part 52. Openings 57, 58
And the two openings 51a and 51b of the lead 51 are inserted into the second cylindrical portion 52 so as to be aligned. Then, the two openings 51a and 51b of the lead 51 are inserted into the peripheral wall portion facing the two openings 57 and 58 of the second cylindrical portion 52,
Embossing is performed to form the two projections 53 and 54 so as to project from the two openings 57 and 58 of the second cylindrical portion 52. Then, the terminal 50 and the lead 51 are joined by caulking the two projections 53 and 54. Thereby, the joining force between the terminal 50 and the lead 51 becomes very large.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these embodiments.
Various modifications are possible based on the technical idea of the present invention.

For example, the first, second, third and fifth
In the embodiment, an opening is formed in the lead, a protrusion is formed in the connector part of one terminal by embossing, the opening of the lead is engaged with the protrusion, and the terminal is crimped by the protrusion. And the lead were joined.
As shown in FIG. 6, the protrusion 61 is formed by embossing the lead 61, and the opening 6 is formed in the connector 63 of the terminal 60.
3a and as shown in FIG.
Of the connector 63 from the lower surface side of the connector 63.
The terminal 60 and the lead 61 may be joined by crimping the head of the projection 64 projecting from the upper surface of the connector 63 by engaging with the terminal a.

[0033]

As described above, according to the method for joining a terminal to a lead and the joining structure of the present invention, the joining strength between the terminal and the lead can be improved as compared with the conventional method. The durability of joining can also be improved.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a step of joining a terminal and a lead according to a first embodiment of the present invention.

FIG. 2 shows a first stage in a step of joining a terminal and a lead according to the first embodiment of the present invention, wherein A shows a front view of the terminal together with a side view, and B shows [2]-[2] of A; It is a rear view in the line direction.

3A and 3B show a second stage in the step of joining the terminal and the lead according to the first embodiment of the present invention, wherein A shows a front view of the terminal and the lead together with a side view of only the terminal, and B shows the [ 3] is a rear view in the direction of the line [3].

4A and 4B show a third stage in the step of joining the terminal and the lead according to the first embodiment of the present invention, wherein A shows a front view of the terminal and the lead together with a side view of only the terminal, and B shows the [ FIG. 4 is a rear view in the direction of line [4]-[4].

5A and 5B show a fourth stage in the step of joining the terminal and the lead according to the first embodiment of the present invention, wherein A shows a front view and a side view of a state where the terminal and the lead are engaged, and FIG. Is A
It is a rear view in the [5]-[5] line direction of FIG.

FIG. 6 shows a fifth stage in the step of joining the terminal and the lead according to the first embodiment of the present invention. FIG. 3 shows a side view of a terminal to which a lead
FIG. 4 is a rear view of A in the [6]-[6] line direction.

FIG. 7 is a plan view of a terminal according to a second embodiment of the present invention.

FIG. 8 is a rear view in the [8]-[8] line direction in FIG. 7;

FIG. 9 is a side view of a terminal according to a second embodiment of the present invention.

FIG. 10 shows a lead according to a second embodiment of the present invention, wherein A is a plan view and B is a side view.

11A and 11B show a terminal to which a lead according to a second embodiment of the present invention is joined, where A is a plan view and B is a side view.

FIG. 12 is a plan view of a terminal according to a third embodiment of the present invention.

FIG. 13 is a rear view taken along the line [13]-[13] in FIG.

FIG. 14 is a side view of a terminal according to a third embodiment of the present invention.

FIG. 15 shows a lead according to a third embodiment of the present invention, wherein A is a plan view and B is a side view.

FIG. 16 is a side view of a terminal to which leads are joined according to a third embodiment of the present invention.

FIG. 17 is an enlarged view of a main part in FIG. 16;

18 is a partially broken side sectional view taken along the line [18]-[18] in FIG.

FIG. 19 is a front view of a terminal according to a fourth embodiment of the present invention.

FIG. 20 is a partially broken side sectional view showing a state where a lead is inserted into a terminal according to a fourth embodiment of the present invention.

FIG. 21 is a partially broken side sectional view showing a state where embossing has been performed on a terminal into which a lead has been inserted according to a fourth embodiment of the present invention.

FIG. 22 is a plan view of a terminal to which leads are joined according to a fourth embodiment of the present invention.

FIG. 23 is a side sectional view taken along the line [23]-[23] in FIG. 22.

FIG. 24 is a plan view of a terminal to which leads are joined according to a sixth embodiment of the present invention.

FIG. 25 is a side sectional view taken along the line [25]-[25] in FIG. 24.

FIG. 26 shows a modification of the present invention, and is a plan view and a side view of a terminal and a lead before joining.

FIG. 27 is a plan view and a side view of a terminal and a lead after bonding, showing a modification of the present invention.

FIG. 28 is a side view of a terminal to which leads are joined according to a fifth embodiment of the present invention.

FIG. 29 is a perspective view showing a conventional step of joining a terminal and a lead.

[Explanation of symbols]

10 ... terminal, 11 ... band, 12 ... projecting part, 13 ...
... Terminal forming part,..., Connector part, 14a... Horizontal part, 15... Protruding part, 15a.

Claims (22)

[Claims] 1. A metal press comprising a band, a plurality of protrusions protruding in one direction from the band, a terminal forming portion wider than each of the protruding portions, and a connector protruding from the terminal forming portion. A method for joining a terminal and a lead, the method including forming a terminal by processing and winding each terminal forming part into a terminal, and performing an embossing process on a tip part of the connector part or the lead; A step of forming an opening at the tip of the lead or the connector section; a step of engaging the opening with a projection formed by the embossing; and a step of caulking the projection. A method for joining a terminal and a lead, wherein the method is performed while intermittently moving the band in one direction. 2. The method according to claim 1, wherein a pair of ribs are formed on the connector portion in parallel with a length direction of the lead, and the opening of the lead is engaged with the protrusion between the pair of ribs. The method for joining a terminal and a lead according to claim 1. 3. A step of performing a pair of rib forming processes perpendicular to the length direction of the lead on the connector portion simultaneously with or before or after the step of performing the embossing process on the connector portion. The method for joining a terminal and a lead according to claim 1. 4. A step of performing an embossing process for forming a projection at a tip of the connector or a lead of a terminal including a cylindrical portion and a connector formed integrally with one end of the cylindrical portion; Forming an opening in the tip portion or the connector portion, engaging the opening with the protruding portion, and caulking the protruding portion. . 5. The method according to claim 5, wherein a pair of ribs are formed on the connector portion in parallel with a length direction of the lead, and the opening of the lead is engaged with the protrusion between the pair of ribs. The method for joining a terminal and a lead according to claim 4. 6. A step of forming a pair of ribs perpendicularly to a longitudinal direction of the lead is added to the connector simultaneously with or before or after the step of embossing the connector. The method for joining a terminal and a lead according to claim 4. 7. The connector according to claim 7, wherein the connector has two or more projections.
The method according to claim 4, wherein the terminal is formed by performing the embossing. 8. A first cylindrical portion having a large diameter, a truncated conical portion formed integrally with one end of the first cylindrical portion, and the first cylindrical portion formed integrally with one end of the truncated conical portion. Forming an opening in a peripheral wall portion of the second cylindrical portion of the terminal comprising a second cylindrical portion having a smaller diameter; and connecting a lead having an opening formed in a tip portion to the second cylindrical portion of the terminal, A step of inserting both openings so as to be aligned; and a projection that penetrates the opening of the lead through a peripheral wall portion of the second cylindrical portion facing the opening and projects from the opening of the second cylindrical portion. A method of joining a terminal and a lead, comprising: a step of performing embossing for forming a portion; and a step of caulking the protrusion. 9. The method according to claim 8, wherein an edge of the opening of the second cylindrical portion is tapered. 10. A pair of slits, each of which is radially opposed to the peripheral wall of the first cylindrical portion, and the peripheral wall is curved so as to protrude radially inward between the pair of slits. The method for joining a terminal and a lead according to claim 8 or 9, wherein: 11. The joint between a terminal and a lead according to claim 8, wherein a pair of slits are formed in the second cylindrical portion so as to face in a radial direction and extend in an axial direction from an outer end. Method. 12. The method according to claim 8, further comprising: performing a pair of rib forming processes on both sides of the projection in the axial direction of the second cylindrical portion together with the step of caulking the projection.
3. The method for joining a terminal and a lead according to 1. 13. A first cylindrical portion having a large diameter, a frustoconical portion integrally formed at one end thereof, and the first cylindrical portion integrally formed at one end of the frustoconical portion. A step of forming two or more openings axially aligned with the peripheral wall of the second cylindrical part of the terminal comprising the second cylindrical part having a smaller diameter; and forming two or more openings at the tip part Inserting the lead into the second cylindrical portion of the terminal so that the two or more openings of the second cylindrical portion and the two or more openings of the lead are aligned; and The two or more openings of the lead are inserted into the peripheral wall portion of the portion facing the two or more openings so that the two or more openings project from the two or more openings of the second cylindrical portion.
A method for joining a terminal and a lead, comprising: a step of performing embossing for forming at least two projections; and a step of caulking the two or more projections. 14. A joint structure between a terminal comprising a cylindrical portion, a terminal integrally formed at one end of the cylindrical portion and a lead fixed to the connector portion and a lead, An opening is formed on one of the connector portion and the tip of the lead, and a projection is formed on the other, and the projection is engaged with the opening and caulked to fix the phases. The connection structure between the terminal and the lead. 15. A pair of ribs are formed in the connector portion in parallel with the length direction of the lead, and the opening of the lead is engaged with the protrusion between the pair of ribs and swaged. 2. The method according to claim 1, wherein
5. A joint structure between the terminal and the lead according to 4. 16. The connector according to claim 1, wherein a pair of ribs are formed perpendicularly to a length direction of the lead, and the opening is formed between the ribs.
5. A joint structure between the terminal and the lead according to 4. 17. The connector according to claim 1, wherein two or more projections are formed on the connector, and two openings for engaging with the projections are formed at the tip of the lead. 16. A joint structure between the terminal and the lead according to 15. 18. A first cylindrical portion having a large diameter, a frustoconical portion integrally formed at one end thereof, and the first cylindrical portion integrally formed at one end of the frustoconical portion. An opening is formed in a peripheral wall portion of the second cylindrical portion of the terminal including a second cylindrical portion having a smaller diameter, and a lead having an opening formed at a distal end portion is connected to the second cylindrical portion of the terminal, and the both openings are formed. Are inserted so as to be aligned with each other, and the projection of the lead is inserted into the peripheral wall of the second cylindrical portion facing the opening, so as to project from the opening of the second cylindrical portion. A joint structure between a terminal and a lead, wherein the terminal and the lead are formed by caulking. 19. The joint structure between a terminal and a lead according to claim 18, wherein a taper is formed at an edge of the opening of the second cylindrical portion. 20. A pair of slits, each of which is radially opposed to the peripheral wall portion of the first cylindrical portion, and the peripheral wall portion is curved so as to protrude radially inward between the pair of slits. 20. The joint structure between a terminal and a lead according to claim 18 or 19. 21. The terminal and lead according to claim 18, wherein a pair of slits are formed radially opposite to the second cylindrical portion and extend axially from an outer end. Joint structure. 22. The joint structure between a terminal and a lead according to claim 18, wherein a pair of upper and lower ribs are formed on both sides of the projection in the axial direction of the second cylindrical portion.