EP3499647A1

EP3499647A1 - Leaf spring and connection terminal block

Info

Publication number: EP3499647A1
Application number: EP18845457.3A
Authority: EP
Inventors: Noriyoshi Machida; Takashi Shizuka
Original assignee: Fuji Electric FA Components and Systems Co Ltd
Current assignee: Fuji Electric FA Components and Systems Co Ltd
Priority date: 2017-09-06
Filing date: 2018-07-23
Publication date: 2019-06-19
Also published as: EP3499647A4; CN109757121A; CN109757121B; JPWO2019049533A1; JP6888670B2; WO2019049533A1

Abstract

Included is a linear shaped free end-side region (51) arranged such that a leading end (51a) of the region (51) projects toward a back side in an insertion direction and a terminal path (56), and a plate surface of the region (51) intersects with the terminal path (56). At an insertion position where a leading end (19a) of a terminal portion (19) reaches the leading end (51a) of the free end-side region (51), an angle (β) formed by the terminal portion (19) and the free end-side region (51) is within 45 degrees ±2 degrees.

Description

Technical Field

The present invention relates to a plate spring and a connection terminal block.

Background Art

PTL 1 discloses a push-in terminal that only requires insertion of an electrical wire into a housing, as a terminal structure for connecting the electrical wire to an electric circuit. The terminal structure uses a plate spring bent into a substantially V-shape. When the electrical wire begins to be inserted, a leading end of the electrical wire first begins to push the plate spring. When the leading end of the electrical wire goes beyond a leading end of the plate spring, the electrical wire is in turn pressed by the leading end of the plate spring, resulting in shifting to an engagement state.

Citation List

Patent Literature

PTL 1: JP 5539809 B

Summary of Invention

Technical Problem

If reaction force received from the plate spring does not significantly change when the leading end of the electrical wire goes beyond the leading end of the plate spring, an operator can hardly receive response, and thus hardly perceives that the shifting to the engagement state has surely been done.
It is an object of the present invention to enable an operator to easily perceive shifting to an engagement state between an electrical wire and a plate spring.

Solution to Problem

A plate spring according to one aspect of the present invention is configured to, when an electrical wire is inserted into an electrical wire insertion hole of a housing, engage with the electrical wire in an inside of the housing to suppress displacement of the electrical wire in a pull-out direction. A position where the electrical wire passes in the inside of the housing is defined as electrical wire path, and the plate spring includes a linear shaped free end-side region arranged such that a leading end of the region projects toward a back side in an insertion direction and the electrical wire path, and a plate surface of the region intersects with the electrical wire path. When the electrical wire is inserted, a leading end of the electrical wire pushes the free end-side region, and then goes beyond the leading end of the free end-side region, resulting in shifting to an engagement state where the leading end of the free end-side region pushes the electrical wire. At an insertion position where the leading end of the electrical wire reaches the leading end of the free end-side region, an angle formed by the electrical wire and the free end-side region is within 45 degrees ±2 degrees.

Advantageous Effects of Invention

According to the present invention, at the insertion position where the leading end of the electrical wire reaches the leading end of the free end-side region, the angle formed by the electrical wire and the free end-side region is within 45 degrees ±2 degrees. Thus, when the leading end of the electrical wire goes beyond the leading end of the plate spring, force applied during insertion of the electrical wire sharply decreases. As a result, the operator receives response, and easily perceives that shifting to the engagement state has surely been done.

Brief Description of Drawings

FIG. 1 is a perspective view of a connection terminal block;
FIG. 2 is a perspective view partially illustrating an inside of the connection terminal block;
FIG. 3 is a cross-sectional view illustrating a state before a ferrule terminal is inserted;
FIG. 4 is a cross-sectional view illustrating a state where a terminal portion is in abutment with a free end-side region of a plate spring;
FIG. 5 is a cross-sectional view illustrating a state where a leading end of the terminal portion has reached a leading end of the free end-side region;
FIG. 6 is a cross-sectional view illustrating a state where insertion of the ferrule terminal has been completed;
FIG. 7 is a cross-sectional view illustrating a state where a tool has been inserted;
FIG. 8 is a graph depicting a relationship between insertion stroke and insertion force in the present invention;
FIG. 9 is a cross-sectional view illustrating a plate spring structure of a comparative example; and
FIG. 10 is a graph depicting a relationship between insertion stroke and insertion force in the comparative example.

Description of Embodiments

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that respective drawings are schematic, and may be different from actual ones. In addition, the following embodiments exemplify devices and methods for embodying the technological idea of the present invention, and do not specify the structures to those described below. In other words, various modifications can be made to the technological idea of the invention without departing from the technological scope prescribed by the claims.

<<Structure>>

FIG. 1 is a perspective view of a connection terminal block.
In the following description, three directions orthogonal to each other will be referred to as widthwise direction, longitudinal direction, and depthwise direction, for convenience.
A connection terminal block 11 is a terminal socket for connecting a relay to an external circuit. On a longitudinal one end side thereof is formed a primary-side terminal section 12 for coil terminals allowing for connection of primary-side lead wires. At a longitudinal center thereof is formed a relay terminal section 13 allowing for connection of, for example, a relay with four pole contacts. On a longitudinal other end side thereof is formed a secondary-side terminal section 14 allowing for connection of secondary-side lead wires for common terminals, a-contact terminals, and b-contact terminals. The primary-side terminal section 12, the relay terminal section 13, and the secondary-side terminal section 14 are integrated by a housing 15.
On an upper surface of the housing 15 that is a front side in the depthwise direction, the relay terminal section 13 is arranged on a further back side than the primary-side terminal section 12 and the secondary-side terminal section 14 in the depthwise direction.
The primary-side terminal section 12 has a spring terminal structure, in which on the upper surface of the housing 15 are formed a plurality of electrical wire insertion holes 21 allowing for insertion of lead wires along the depthwise direction. On a one end side thereof in the widthwise direction are formed two electrical wire insertion holes 21c and 21d for one of the polarities, and on the other end side thereof in the widthwise direction are formed two electrical wire insertion holes 21a and 21b for the other polarity. Accordingly, the primary-side terminal section 12 includes four electrical wire insertion holes 21 in total. The two electrical wire insertion holes 21a and 21b or 21c and 21d having the same polarity are arranged by being shifted in both the widthwise direction and the longitudinal direction. On the upper surface of the housing 15 are formed a plurality of tool insertion holes 22 allowing for insertion of tools along the depthwise direction. Each one tool insertion hole 22 is provided for each of the electrical wire insertion holes 21a to 21d, and arranged on a longitudinal other end side of the section 12 relative to the electrical wire insertion holes 21a to 21d. Accordingly, the primary-side terminal section 12 includes four tool insertion holes 22 in total.
The relay terminal section 13 has a plug-in terminal structure, in which on the upper surface of the housing 15 are formed a plurality of plug insertion inlets 23 allowing for insertion of plugs in the depthwise direction. On a longitudinal one end side thereof are formed two plug insertion inlets 23 for coil terminals. On a longitudinal other end side thereof are formed three plug insertion inlets 23 for a common terminal, an a-contact terminal, and a b-contact terminal along the longitudinal direction. The three plug insertion inlets are regarded as one set, and four sets of the three plug insertion inlets are arrayed along the widthwise direction. Accordingly, the relay terminal section 13 includes 14 plug insertion inlets 23 in total.
The secondary-side terminal section 14 has a spring terminal structure, in which on the upper surface of the housing 15 are formed a plurality of electrical wire insertion holes 24 corresponding to four poles, which holes allow for insertion of lead wires in the depthwise direction. The secondary-side terminal section 14 has three steps whose depthwise heights become lower, in order from the one end side to the other end side in the longitudinal direction. On an upper stage are formed electrical wire insertion holes 24a to 24h, two of which per pole are for, for example, b-contact terminals. On a middle stage are formed electrical wire insertion holes 24i to 24p, two of which per pole are for, for example, a-contact terminals . On a lower stage are formed electrical wire insertion holes 24q to 24x, two of which per pole are for, for example, common terminals. On each stage, the two electrical wire insertion holes 24 (for example, 24a and 24b) of one electrode are arranged by being shifted in both the widthwise direction and the longitudinal direction. The six electrical wire insertion holes 24 (for example, 24a, 24b, 24i, 24j, 24q, and 24r) are regarded as one set, and four pole sets are arranged in the widthwise direction. Accordingly, the secondary-side terminal section 14 includes 24 electrical wire insertion holes 24 in total. On the upper surface of the housing 15 are formed a plurality of tool insertion holes 25 allowing for insertion of tools in the depthwise direction. On each stage, each one tool insertion hole 25 is provided for each of the electrical wire insertion holes 24a to 24x, and is respectively arranged on a longitudinal one end side of the section 14 relative to the electrical wire insertion holes 24. Accordingly, the secondary-side terminal section 14 includes 24 tool insertion holes 25 in total.
FIG. 2 is a perspective view partially illustrating an inside of the connection terminal block.
Since the primary-side terminal section 12 and the secondary-side terminal section 14 are basically the same in structure, the secondary-side terminal section 14 will be exemplified for description hereinbelow.
In an inside of the housing 15 is provided a blade-receiving spring 31 on a back side of each plug insertion hole 23 in the depthwise direction. The blade-receiving spring 31 includes a pair of spring pieces facing each other and urging each other to sandwich and hold a plug inserted between the pair of spring pieces. A spring metal fitting 32 is provided on a back side of each of the electrical wire insertion holes 24a to 24x in the depthwise direction, and each spring metal fitting 32 is attached to an intermediate base 46. The spring metal fitting 32 includes a pressing surface 33 substantially parallel with the depthwise direction and the widthwise direction and a plate spring 34 urged against the pressing surface 33, and sandwiches and holds a lead wire inserted between the pressing surface 33 and the plate spring 34. On a further back side than the blade-receiving spring 31 and the spring metal fitting 32 in the depthwise direction is provided a relay conductive plate 35 electrically connecting these components. Two relay conductive plates 35 are provided for coil terminals, and each four relay conductive plates 35 are provided for common terminals, a-contact terminals, and b-contact terminals.
A ferrule terminal 17 is crimped to a lead wire 16 (an electrical wire) to be inserted into the electrical wire insertion hole 24. The ferrule terminal 17 is a bar-shaped crimp terminal for preventing a stranded wire from being loosened to stabilize the quality of electrical connection. The ferrule terminal 17 includes an insulated collar portion 18 and a terminal portion 19. On a leading end side of the collar portion 18 is formed a tapered surface 18a whose diameter becomes smaller toward the leading end thereof, and the terminal portion 19 is thinner than a diameter of the collar portion 18.
When the lead wire 16 is inserted into the electrical wire insertion hole 24 of the housing 15, the plate spring 34 engages with the terminal portion 19 in the inside of the housing 15 to suppress displacement in a pull-out direction. Additionally, when a tool (unillustrated) is inserted into the tool insertion hole 25, the engagement with the terminal portion 19 is released in the inside of the housing 15.
Next will be a description of the structure of the electrical wire insertion holes 24.
The electrical wire insertion holes 24 formed on the secondary-side terminal section 14 are all the same in structure, and thus, the electrical wire insertion hole 24 formed on the lower stage will be exemplified for description hereinbelow.
FIG. 3 is a cross-sectional view illustrating a state before a ferrule terminal is inserted.
The electrical wire insertion hole 24 includes a large diameter portion 43, an abutting portion 44, and a small diameter portion 45, in order toward the inside of the housing 15. The large diameter portion 43 has a diameter slightly larger than the collar portion 18. The abutting portion 44 is a tapered surface whose diameter becomes smaller toward a back side in the depthwise direction. A tapered angle of the abutting portion 44 relative to the depthwise direction is larger than an angle of the tapered surface 18a relative to the depthwise direction. The small diameter portion 45 has a diameter smaller than the diameter of the collar portion 18 and larger than a diameter of the terminal portion 19.
The plate spring 34 is formed of, for example, stainless steel, and has a uniform plate thickness of about 0.5mm. The plate spring 34 includes a free end-side region 51, a fixed end-side region 52, a first bent region 53, a second bent region 54, and a tool contact region 55. A position where the terminal portion 19 passes in the inside of the housing 15 is defined as a terminal path 56 (an electrical wire path) .
The free end-side region 51 is a region that is arranged such that a leading end of the region 51 linearly projects toward a back side in an insertion direction and the terminal path 56, and a plate surface of the region 51 intersects with the terminal path 56 and that is urged against the pressing surface 33. In a state where the ferrule terminal 17 is not inserted, a leading end 51a of the free end-side region 51 is in abutment with the pressing surface 33, and an angle α formed by the terminal path 56 and the free end-side region 51 is set to be within 70 degrees ±2 degrees.
The fixed end-side region 52 is a linear shaped region fixed to the intermediate base 46 and extending in parallel with the terminal path 56.
The first bent region 53 is a region interposed between the free end-side region 51 and the fixed end-side region 52 and bent toward a side that projects when seen from a front side in the insertion direction. When curvature radius is too small, plastic deformation easily occurs, and moreover, elastic force is weakened. Thus, the curvature radius is set to be twice or more than the plate thickness, and preferably three times or more than that. Accordingly, herein, the curvature radius is preferably set to 1.5 mm or more.
The second bent region 54 is a region interposed between the free end-side region 51 and the first bent region 53 and bent toward a side that is recessed when seen from the front side in the insertion direction or from the terminal path 56.
The tool contact region 55 is a linear shaped region which is interposed between the first bent region 53 and the second bent region 54 and which is, when a tool is inserted, pushed to an outside of the terminal path 56 by an outer peripheral surface of the tool.
Operation of the plate spring 34 will be described.
FIG. 4 is a cross-sectional view of a state where the terminal portion is in abutment with the free end-side region of the plate spring.
When the ferrule terminal 17 begins to be inserted into the electrical wire insertion hole 24, first, the terminal portion 19 passes through the small diameter portion 45, and a leading end 19a of the terminal portion 19 abuts with the plate surface of the free end-side region 51 of the plate spring 34.
When the ferrule terminal 17 is inserted from this state, the leading end 19a of the terminal portion 19 pushes the plate surface of the free end-side region 51 of the plate spring 34 toward the back side in the depthwise direction. Then, a range of from the free end-side region 51 to the tool contact region 55 pivots around a curvature center of the first bent region 53 serving as a fulcrum, and narrows an opening degree of the tool contact region 55 with respect to the fixed end-side region 52, i.e., elastically deforms the plate spring 34 in a closing direction.
FIG. 5 is a cross-sectional view of a state where the leading end of the terminal portion has reached the leading end of the free end-side region.
When the ferrule terminal 17 is further pushed in, the leading end 19a of the terminal portion 19 reaches the leading end 51a of the free end-side region 51. In this state, an angle β formed by the terminal portion 19 and the free end-side region 51 is set to be within 45 degrees ±2 degrees.
When the ferrule terminal 17 is still further pushed in and the leading end 19a of the terminal portion 19 goes beyond the leading end 51a of the free end-side region 51, the terminal portion 19 enters so as to thrust itself between the leading end 51a of the free end-side region 51 and the pressing surface 33. Then, due to elastic force of the plate spring 34, an engagement state is brought about in which the leading end 51a of the free end-side region 51 presses the terminal portion 19 against the pressing surface 33.
The free end-side region 51 projects toward the back side in the insertion direction. Thus, in the above engagement state, displacement of the terminal portion 19 in the insertion direction occurs in a forward direction, which is therefore permissible. On the other hand, displacement thereof in the pull-out direction occurs in an opposite direction where the free end-side region 51 is rubbed backward, so that the terminal portion 19 is caught by the leading end 51a of the free end-side region 51 by, thereby suppressing displacement in the pull-out direction. This can suppress loosening and coming-off of the ferrule terminal 17. In this manner, the terminal portion 19 is sandwiched and hold by the leading end 51a of the free end-side region 51 and the pressing surface 33, thereby resulting in a restrained state where the terminal portion 19 is held. Note that since the terminal portion 19 has a width size of about 1.5 mm, a gap is formed between the leading end 51a of the free end-side region 51 and the pressing surface 33 by the width size of the terminal portion 19.
Herein, for convenience, the ferrule terminal 17 has been illustrated without any inclination. However, actually, the ferrule terminal 17 becomes inclined to the depthwise direction, since the terminal portion 19 is pressed against the pressing surface 33 side by the plate spring 34. Accordingly, the diameter of the large diameter portion 43, the tapered angle of the abutting portion 44, the diameter of the small diameter portion 45, and the like are set so as to positively allow for a slight inclination of the ferrule terminal 17 when inserted.
FIG. 6 is a cross-sectional view of a state where insertion of the ferrule terminal has been completed.
When the ferrule terminal 17 is further pushed in, and then, a leading end side of the tapered surface 18a of the collar portion 18 abuts with the abutting portion 44 of the electrical wire insertion hole 24, further insertion is inhibited and stopped. In this case, the leading end 19a of the terminal portion 19 is set so as to be spaced away from a bottom surface 47 of the inside of the housing 15. Herein, the collar portion 18 is about 6.0 mm in length, and the terminal portion 19 is about 8.0 mm in length, so that the ferrule terminal 17 used is about 14.0 mm in total length.
FIG. 7 is a cross-sectional view of a state where a tool has been inserted.
When the plate spring 34 is in engagement with the terminal portion 19, the tool insertion hole 25, seen from the front side in the depthwise direction, is arranged at a position overlapping with a region from a longitudinal other end side of the free end-side region 51 up to a longitudinal one end side of the first bent region 53. The tool insertion hole 25 is formed to be inclined by about 10 degrees to the depthwise direction so as to become closer to the terminal portion 19 toward the back side in the depthwise direction. When the plate spring 34 is in engagement with the terminal portion 19, the tool contact region 55 extends substantially in parallel with an axial line of the tool insertion hole 25. As a tool 61, for example, a flathead screwdriver is used.
When the tool 61 is inserted, an outer peripheral surface of the tool 61 slidingly contacts with a range from the longitudinal one end side of the first bent region 53 up to the tool contact region 55, and pushes the tool contact region 55 away to the outside of the terminal portion 19. Alternatively, a leading end of the tool 61 abuts with a range from the longitudinal other end side of the free end-side region 51 up to the second bent region 54, and pushes down the free end-side region 51. In this manner, pushing the tool contact region 55 away to the outside of the terminal portion 19 or pushing down the free end-side region 51 narrows an opening degree of the tool contact region 55 with respect to the fixed end-side region 52, i.e., elastically deforms the plate spring 34 in the closing direction. This releases the engagement state between the leading end 51a of the free end-side region 51 and the terminal portion 19, whereby the terminal portion 19 is released from the restraint by the plate spring 34, thus enabling the ferrule terminal 17 to be pulled out.

<<Operation>>

Next will be a description of main effects of the embodiment.
The angle β formed by the terminal portion 19 and the free end-side region 51 is set to be within 45 degrees ±2 degrees in the state where the leading end 19a of the terminal portion 19 reaches the leading end 51a of the free end-side region 51. Setting the angle as above leads to sharp reduction of reaction force received during insertion of the ferrule terminal 17 when the leading end 19a of the terminal portion 19 goes beyond the leading end 51a of the free end-side region 51. This results from significant reduction of friction coefficient µ. In other words, from an operator's standpoint, since force received during insertion of the ferrule terminal 17 is suddenly reduced, the operator receives response, and easily perceives that shifting to the engagement state has surely been done.
FIG. 8 is a graph depicting a relationship between insertion stroke and insertion force.
At an insertion stroke of 0, the leading end 19a of the terminal portion 19 is in abutment with the plate surface of the free end-side region 51 of the plate spring 34, as illustrated in FIG. 4. When the ferrule terminal 17 begins to be inserted from this state, insertion force progressively increases due to reaction force caused by elastic deformation of the plate spring 34 and friction resistance caused by sliding of the leading end 19a of the terminal portion 19 on the plate surface of the free end-side region 51.
At an insertion stroke of x1, the leading end 19a of the terminal portion 19 reaches the leading end 51a of the free end-side region 51, as illustrated in FIG. 5. This is the time when the insertion force is at its peak. Experiment shows that when, at the above insertion stroke, the angle β formed by the terminal portion 19 and the free end-side region 51 is set to be within 45 degrees ±2 degrees, the friction coefficient µ significantly decreases as the ferrule terminal 17 is further inserted, whereby the insertion force sharply decreases.
Now, a comparative example will be described.
FIG. 9 is a cross-sectional view illustrating a plate spring structure of the comparative example.
Herein, a plate spring 71 bent in a substantially V-shape is used.
FIG. 9A is a cross-sectional view of a state before the ferrule terminal 17 is inserted.
FIG. 9B is a cross-sectional view of a state where the terminal portion 19 is in abutment with the plate spring 71. In this state, an angle formed by the terminal portion 19 and a leading end of the plate spring 71 is about 45 degrees.
FIG. 9C is a cross-sectional view of a state where the leading end of the terminal portion 19 has reached the leading end of the plate spring 71. In this state, the angle formed by the terminal portion 19 and the leading end of the plate spring 71 is about 30 degrees.
FIG. 9D is a cross-sectional view of a state where insertion of the ferrule terminal 17 has been completed.
FIG. 10 is a graph depicting a relationship between insertion stroke and insertion force in the comparative example.
At an insertion stroke of 0, the leading end of the terminal portion 19 is in abutment with the leading end of the plate spring 71, as illustrated in FIG. 9B. When the ferrule terminal 17 begins to be inserted from this state, insertion force progressively increases due to reaction force caused by elastic deformation of the plate spring 71 and friction resistance caused by sliding of the leading end of the terminal portion 19 on a plate surface of the plate spring 71.
At an insertion stroke of x1, the leading end of the terminal portion 19 reaches the leading end of the plate spring 71, as illustrated in FIG. 9C. This is the time when the insertion force is at its peak. Experiment shows that during further insertion of the ferrule terminal 17, the friction coefficient µ is not significantly reduced, and the insertion force is slowly reduced. Thus, when there is no significant change in force applied during insertion of the ferrule terminal 17, the operator can hardly receive response, and hardly perceives that shifting to the engagement state has surely been done.
In the embodiment, to set the angle β formed by the terminal portion 19 and the free end-side region 51 to be within 45 degrees ±2 degrees, first, in the state where the ferrule terminal 17 is not inserted yet, the angle α formed by the terminal path 56 and the free end-side region 51 is set to be within 70 degrees ±2 degrees. Additionally, the fixed end-side region 52, the first bent region 53, and the second bent region 54 are formed. Providing the second bent region 54 enables values of the angles β and α to be larger than in the structure of the comparative example, whereby it can be achieved that β is nearly equal to 45 degrees and α is nearly equal to 70 degrees.
In addition, the first bent region 53 is set to have a curvature radius of twice or more than the plate thickness. This can suppress plastic deformation of the plate spring 34 and reduction of elastic force.
Furthermore, providing the tool contact region 55 allows the plate spring 34 to be smoothly bent via the tool contact region 55 when the tool 61 is inserted, thereby enabling easy release of the engagement state with the terminal portion 19.

<<Modifications>>

While the above embodiment has been described for the case where the ferrule terminal 17 is crimped to the lead wire 16, the invention is not limited thereto, and a bare wire, whether a single wire or a stranded wire, may be used as it is.
While the above embodiment has been described with respect to the c-contact relay including a-contact terminals and b-contact terminals in combination, the invention is not limited thereto, and also applicable to a-contact relays and b-contact relays. In addition, while the relay with the four pole contacts has been described, the invention is not limited thereto, and also applicable to relays with a single pole contact, two pole contacts, or three pole contacts. Furthermore, the invention is applicable not only to relays but also to timers.
While the above embodiment has been described with respect to the terminal socket for connecting a relay, a timer, or the like to an external circuit, the invention is not limited thereto. In short, the invention is also applicable to any other electrical equipment or auxiliary equipment having a spring terminal structure capable of holding the ferrule terminal 17 inserted into the housing 15.
While the present invention has been described by referring to the limited number of embodiments, the scope of the present invention is not limited thereto. Modifications of embodiments based on the above disclosure are obvious to those skilled in the art.

Reference Signs List

11:: Connection terminal block
12:: Primary-side terminal section
13:: Relay terminal section
14:: Secondary-side terminal section
15:: Housing
16:: Lead wire
17:: Ferrule terminal
18:: Collar portion
18a:: Tapered surface
19:: Terminal portion
19a:: Leading end
21:: Electrical wire insertion hole
22:: Tool insertion hole
23:: Plug insertion inlet
24:: Electrical wire insertion hole
25:: Tool insertion hole
30:: Angle
32:: Spring metal fitting
33:: Pressing surface
34:: Plate spring
35:: Relay conductive plate
43:: Large diameter portion
44:: Abutting portion
45:: Small diameter portion
46:: Intermediate base
47:: Bottom surface
51:: Free end-side region
51a:: Leading end
52:: Fixed end-side region
53:: First bent region
54:: Second bent region
55:: Tool contact region
56:: Terminal path
61:: Tool
71:: Plate spring

Claims

A plate spring configured to, when an electrical wire is inserted into an electrical wire insertion hole of a housing, engage with the electrical wire in an inside of the housing to suppress displacement of the electrical wire in a pull-out direction, wherein,
a position where the electrical wire passes in the inside of the housing is defined as an electrical wire path,
the plate spring includes a linear shaped free end-side region arranged such that a leading end of the region projects toward a back side in an insertion direction and the electrical wire path, and a plate surface of the region intersects with the electrical wire path,
when the electrical wire is inserted, a leading end of the electrical wire pushes the free end-side region, and then goes beyond the leading end of the free end-side region, resulting in shifting to an engagement state where the leading end of the free end-side region pushes the electrical wire; and
at an insertion position where the leading end of the electrical wire reaches the leading end of the free end-side region, an angle formed by the electrical wire and the free end-side region is within 45 degrees ±2 degrees.
The plate spring according to claim 1, wherein in a state where the electrical wire is not inserted, an angle formed by the electrical wire path and the free end-side region is within 70 degrees ±2 degrees.
The plate spring according to claim 1 or 2, comprising a linear shaped fixed end-side region fixed to the housing and extending in parallel with the electrical wire path, a first bent region interposed between the free end-side region and the fixed end-side region and bent toward a side that projects when seen from a front side in the insertion direction, and a second bent region interposed between the free end-side region and the first bent region and bent toward a side that is recessed when seen from the front side in the insertion direction or from the electrical wire path.
The plate spring according to claim 3, wherein the first bent region has a curvature radius twice or more than a plate thickness.
The plate spring according to claim 3 or 4, wherein when a tool is inserted into a tool insertion hole of the housing, the engagement with the electrical wire is released in the inside of the housing; and wherein the plate spring comprises a linear shaped tool contact region interposed between the first bent region and the second bent region, the tool contact region being pushed to an outside of the electrical wire by an outer peripheral surface of the tool when the tool is inserted.
A connection terminal block comprising the plate spring according to any one of claims 1 to 5.