TWI828038B - Screw retention structures, terminal blocks and electrical equipment - Google Patents

Abstract

In order to provide a novel screw holding structure that can hold terminal screws at a holding position away from the terminal portion without using coil springs, the screw holding structure of the present invention includes: a housing; a terminal portion disposed in the housing and including a female thread portion; The terminal screw includes a male thread portion that can be screwed into the female thread portion, a head portion with a diameter larger than that of the male thread portion, a neck portion that connects the male thread portion and the head portion along the axial direction, and a ring arranged around the neck portion. shaped washer; and leaf spring, arranged in the housing. The terminal screw is configured to be movable within the housing between the following positions: a connecting position where the male thread part is threaded into the female thread part and is connected to the terminal part; and a holding position where the screw is separated from the terminal part in the axial direction. The leaf spring is configured such that one end portion is in contact with the washer surface from the male thread portion side, and the terminal screw is pushed to the holding position when the threaded engagement between the female thread portion and the male thread portion is released.

Description

Screw retention structures, terminal blocks and electrical equipment

The present invention relates to a screw holding structure, a terminal block and electrical equipment including the screw holding structure.

Previously known is a wire connection method in which the front end of the wire inserted into the housing through the wire insertion opening is pressed with a terminal screw from a direction intersecting the wire insertion direction, thereby pressing it to Terminal portions provided inside the housing are electrically connected. In this wire connection method, in order to facilitate the insertion of the wire, a screw holding structure (also called a hold on structure) that holds the terminal screw at a holding position away from the terminal portion is usually used. As this screw holding structure, for example, what is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2011-34735) is known. Patent Document 1 discloses a screw holding structure that holds a terminal screw at a holding position away from the terminal portion by the urging force of a coil spring having an end portion attached to a washer of the terminal screw. [Prior art documents] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2011-34735

[Problem to be solved by the invention]

However, in the screw holding structure of Patent Document 1, when attaching the terminal screw to the terminal block or electrical equipment, it is necessary to attach the terminal screw in a compressed state of the long coil spring. Therefore, there are problems such as large displacement of the coil spring and poor assemblability. In addition, when the compressed coil spring elastically recovers, it may be repelled in an unexpected direction. Therefore, a member for limiting the repelling direction of the coil spring is required.

In order to solve the above problems, an object of the present invention is to provide a novel screw holding structure capable of holding terminal screws at a holding position away from the terminal portion without using a coil spring, and a terminal block and electrical equipment including the screw holding structure. [Means to solve the problem]

In order to achieve the above object, one aspect of the screw holding structure of the present invention includes: shell; The terminal part is arranged in the housing and includes a female thread part; A terminal screw includes a male thread portion capable of being screwed into the female thread portion, a head portion having a diameter larger than that of the male thread portion, a neck portion connecting the male thread portion and the head portion along an axial direction, and an annular gasket arranged around the neck; and a leaf spring, disposed in the housing, and The terminal screw is configured to be movable within the housing between the following positions: a connection position in which the male thread portion is screwed into the female thread portion and is connected to the terminal portion; and a holding position. , separated from the terminal portion in the axial direction, The leaf spring is configured as follows: one end portion contacts the washer surface from the male thread portion side, and when the threaded engagement between the female thread portion and the male thread portion is released, the terminal screw is pushed to the desired position. to maintain the position. [Effects of the invention]

According to the screw holding structure of one aspect of the present invention, it is possible to provide a novel screw holding structure capable of holding the terminal screw at a holding position away from the terminal portion without using a coil spring.

One aspect of the screw holding structure of the present invention includes: shell; The terminal part is arranged in the housing and includes a female thread part; A terminal screw includes a male thread portion capable of being screwed into the female thread portion, a head portion having a diameter larger than that of the male thread portion, a neck portion connecting the male thread portion and the head portion along an axial direction, and an annular gasket arranged around the neck; and a leaf spring, disposed in the housing, and The terminal screw is configured to be movable within the housing between the following positions: a connection position in which the male thread portion is screwed into the female thread portion and is connected to the terminal portion; and a holding position. , separated from the terminal portion in the axial direction, The leaf spring is configured as follows: one end portion contacts the washer surface from the male thread portion side, and when the threaded engagement between the female thread portion and the male thread portion is released, the terminal screw is pushed to the desired position. to maintain the position.

According to this structure, since one end of the leaf spring contacts the washer surface from the male thread portion side and pushes the terminal screw to the holding position, the urging force of the leaf spring can be imparted to the washer in a more balanced manner. In addition, compared with coil springs, leaf springs can easily control the repelling direction when elastically recovering from a bent state to a flat plate shape, and have good assembly properties. Therefore, according to the above structure, it is possible to provide a novel screw holding structure that holds the terminal screw at a holding position away from the terminal portion without using a coil spring.

Furthermore, the terminal screw may include an annular clamping member that clamps one end of the leaf spring between the washer and the terminal screw. According to this structure, one end portion of the leaf spring can be firmly held between the washer and the clamping member, and the urging force of the leaf spring can be imparted to the washer in a more balanced manner. In addition, since the washer is interposed between the head of the terminal screw and the leaf spring, when the head is rotated by the driver, the rotational force of the driver can be prevented from being directly applied to the leaf spring, thereby suppressing the torsion of the leaf spring. Furthermore, since the clamping member is interposed between the terminal part and the leaf spring on the male thread part side of the terminal screw, it is possible to suppress the electric wire from coming into contact with the leaf spring when the electric wire is inserted between the terminal part and the terminal screw.

Moreover, a groove part may be provided in the housing, and the other end part of the leaf spring may be inserted into the groove part to hold the leaf spring. According to this structure, assemblability can be further improved.

In addition, a restricting member may be included. The restricting member is located between the terminal screw and the other end of the leaf spring and includes an arc-shaped portion. The arc-shaped portion prevents the terminal screw from moving from the holding position. When moving toward the connection position, the portion in contact between one end and the other end of the leaf spring limits the bending amount of the leaf spring. According to this structure, excessive bending of the leaf spring can be suppressed by the restricting member. For example, when the terminal screw is in the connection position and the bending amount of the leaf spring is increased, even if an external force or the like is applied to the housing and an impact is applied to the leaf spring, the bending amount of the leaf spring can be suppressed from further increasing.

Furthermore, the washer may include a first guide protrusion protruding toward the head side of the terminal screw, and the housing may include a first guide groove, and the first guide groove may be When the terminal screw moves between the connecting position and the holding position, the first guide protrusion is allowed to slide along the axial direction. According to this structure, the movement of the terminal screw in the axial direction can be restricted by the first guide protrusion sliding on the first guide groove, so that the urging force of the leaf spring can be imparted to the washer in a more balanced manner.

Furthermore, the washer may include a second guide protrusion protruding toward the head side at a position facing the first guide protrusion across the head when viewed from the axial direction, and the case may be The body includes a second guide groove portion for the second guide protrusion to slide along the axial direction when the terminal screw moves between the connection position and the holding position. . According to this structure, the movement of the terminal screw in the axial direction can be more reliably restricted by the first guide protrusion and the second guide protrusion sliding in the first guide groove and the second guide groove, thereby achieving better balance. Apply the urging force of the leaf spring to the washer well.

Furthermore, the washer may include a protective member protruding toward the head side to prevent the leaf spring from being exposed while the terminal screw moves between the connecting position and the holding position. It is constructed in such a manner that the plate spring is hidden from the movement path of the terminal screw. According to this structure, when the head of the terminal screw is rotated by the driver, it can be suppressed that the driver mistakenly deviates from the movement path of the terminal screw and comes into contact with the leaf spring.

Furthermore, the protective member may be formed in a rod shape or a substantially rectangular plate shape having a longitudinal direction along the axial direction. According to this structure, it can be arranged in a space-saving manner and can be easily produced.

In addition, the screw holding structure may be provided on a terminal block or electrical equipment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to this embodiment. In addition, substantially the same members are assigned the same symbols in the drawings.

In addition, for the convenience of explanation below, terms indicating directions such as "upper", "lower", "front", "rear", "left" and "right" are used assuming the state of normal use. However, this does not apply to the present invention. The screw holding structure is limited in use, etc.

(implementation form) The screw connection structure according to the embodiment of the present invention will be described using FIG. 1 . FIG. 1 is a perspective view of a push button switch including a screw connection structure according to an embodiment of the present invention. A push button switch is an example of an electrical device.

The push button switch 1 of this embodiment includes a housing 2 and a plunger 3 . The housing 2 and the plunger 3 include insulating members.

The housing 2 includes a front side housing assembly 21 and a rear side housing assembly 22 . The upper surface of the housing 2 is provided with a through hole 23 for allowing the plunger 3 to move in the up-down direction Z. The housing 2 is formed to be left-right symmetrical when viewed from the front-rear direction Y (the direction from the lower right to the upper left in FIG. 1 ). Electrical wire insertion openings 24 through which power supply wires (not shown) pass are formed on the left and right sides of the housing 2 .

The plunger 3 is a hollow substantially square columnar rod extending along the up-down direction Z. As shown in FIG. 1 , the plunger 3 is accommodated inside the housing 2 so that the front end portion 31 protrudes to the outside of the housing 2 through the through hole 23 . The corners of the front end portion 31 of the plunger 3 in the left-right direction X are chamfered and formed into a substantially arc shape when viewed from the front-rear direction Y. In this embodiment, the left-right direction X, the front-rear direction Y, and the up-down direction Z are orthogonal to each other.

FIG. 2 is a cross-sectional view of the push button switch 1 of FIG. 1 . FIG. 3 is a perspective view showing a state in which the front case assembly 21 is removed from the push button switch 1 of FIG. 1 . FIG. 4 is a perspective view showing a state in which the rear case assembly 22 is removed from the push button switch 1 of FIG. 1 . FIG. 5 is a perspective view showing a state in which the plunger 3 is further removed from the state shown in FIG. 4 . Figure 6 is a perspective view of the terminal screw.

As shown in FIGS. 2 to 5 , a terminal portion 4 , a terminal screw 5 , and a leaf spring 6 are arranged in the housing 2 .

The terminal part 4 is fixedly mounted on the housing 2 . The terminal portion 4 includes a conductive member. In this embodiment, the terminal portion 4 is formed by punching and bending a metal plate. The terminal portion 4 is provided with a female thread portion 41 extending in the thickness direction. A fixed contact 42 is attached to one end of the terminal portion 4 located close to the plunger 3 .

The terminal screw 5 includes a male thread portion 51 capable of being screwed into the female thread portion 41 , a head portion 52 having a larger diameter than the male thread portion 51 , and a neck portion 53 connecting the male thread portion 51 and the head portion 52 along the axial direction A1 . The head 52 is provided with a screw groove 52a into which a driver can be inserted. An annular gasket 54 is arranged around the neck 53 . Moreover, in this embodiment, the annular clamping member 55 which clamps the one end part 6a of the leaf spring 6 with the washer 54 is arrange|positioned around the neck part 53. In this embodiment, the clamping member 55 is made of the same metal as the gasket 54 .

The terminal screw 5 is configured to be movable in the housing 2 between the following positions: a connection position P1 connected to the terminal part 4 by the male thread part 51 being screwed into the female thread part 41; and a connection position P1 from the terminal part 4 to the terminal part 4. The holding position P2 is separated in the axis direction A1. When a wire (not shown) is inserted into the wire insertion opening 24 , the terminal screw 5 moves from the holding position P2 to the connection position P1 and pushes the connection terminal (not shown) attached to the front end of the wire toward the terminal portion 4 . Thereby, the connection terminal of the electric wire and the terminal part 4 are electrically connected.

The washer 54 includes a first guide protrusion 56 that protrudes toward the head 52 side of the terminal screw 5 and extends along the axial direction A1. The housing 2 includes a first guide groove portion 25 for allowing the first guide protrusion 56 to slide along the axial direction A1 when the terminal screw 5 moves between the connection position P1 and the holding position P2. Furthermore, in this embodiment, the washer 54 includes the second guide protrusion 57 at a position facing the first guide protrusion 56 across the head 52 when viewed from the axial direction A1. The second guide protrusion 57 faces the head. The portion 52 side protrudes and extends along the axial direction A1. The housing 2 includes a second guide groove portion 26 for allowing the second guide protrusion 57 to slide along the axial direction A1 when the terminal screw 5 moves between the connection position P1 and the holding position P2.

In this embodiment, the first guide protrusion 56 and the second guide protrusion 57 are provided at positions facing each other across the center of the head 52 when viewed from the axial direction A1. Furthermore, the first guide protrusion 56 and the second guide protrusion 57 are formed in a substantially rectangular plate shape with corners chamfered. The first guide groove portion 25 and the second guide groove portion 26 extend along the axial direction A1 to a position proximal to the outer surface of the housing 2 . That is, one end portion of the first guide groove portion 25 and one end portion of the second guide groove portion 26 away from the terminal portion 4 are located in the housing 2 . When the front end of the first guide protrusion 56 comes into contact with one end of the first guide groove 25 , the movement of the terminal screw 5 in the axial direction A1 is restricted, and the terminal screw 5 is held at the holding position P2 . Furthermore, since the front end of the second guide protrusion 57 comes into contact with one end of the second guide groove 26, the movement of the terminal screw 5 in the axial direction A1 is restricted, and the terminal screw 5 is held at the holding position P2.

In addition, the washer 54 includes a protective member 58 that protrudes toward the head 52 side to prevent the leaf spring 6 from being exposed to the movement of the terminal screw 5 when the terminal screw 5 moves between the connecting position P1 and the holding position P2. The path is constructed in such a way that the leaf spring 6 is hidden. In this embodiment, the protective member 58 is formed in a substantially rectangular plate shape having a longitudinal direction along the axial direction A1 and having corners chamfered. The length of the protective member 58 in the axial direction A1 is longer than the distance between the connection position P1 and the holding position P2. In this embodiment, the protective member 58 is provided to protrude to the outside of the housing 2 when the terminal screw 5 is located at the holding position P2 (see the protective member 58 on the right side of FIG. 3 ). Thereby, the protective member 58 functions as a display part that provides different visual indicators when the terminal screw 5 is located at the connection position P1 and when it is located at the holding position P2.

The plate spring 6 is configured such that one end 6 a is in surface contact with the washer 54 from the male thread portion 51 side, and the terminal screw 5 is pushed to the holding position P2 when the female thread portion 41 and the male thread portion 51 are unthreaded. The housing 2 is provided with a groove 27 into which the other end 6 b of the leaf spring 6 is inserted and the leaf spring 6 is held.

A restricting member 28 is provided between the terminal screw 5 and the other end 6 b of the leaf spring 6 . The restricting member 28 includes an arc-shaped portion 28 a that contacts a portion between one end 6 a and the other end 6 b of the leaf spring 6 when the terminal screw 5 moves from the holding position P2 to the connecting position P1 And the bending amount of the leaf spring 6 is limited.

In addition, a movable contact 32 is provided movably in the up-down direction Z at a position facing the fixed contact 42 of each terminal portion 4 . The movable contactor 32 is provided on the contact arm portion 33 extending in the left-right direction X. The contact arm portion 33 includes a conductive member. A hemispherical protrusion 34 protruding upward is provided at the center of the contact arm 33 . The lower end of the first coil spring 35 is attached to the protrusion 34 . The upper end of the first coil spring 35 is mounted on the plunger 3 .

Moreover, as shown in FIG. 5 , a second coil spring 36 is provided on the side closer to the rear side case assembly 22 than the first coil spring 35 . The lower end of the second coil spring 36 is mounted on the boss 29 protruding upward from the inner bottom surface of the housing 2 . The upper end of the second coil spring 36 is mounted on the plunger 3 to push the plunger 3 upward. The second coil spring 36 is configured to be longer than the first coil spring 35 .

When the plunger 3 is pushed downward against the urging force of the first coil spring 35 and the second coil spring 36 , the contact arm 33 moves downward, and the movable contact 32 comes into contact with the fixed contact 42 . Electric wires are inserted into the left and right wire insertion openings 24 of the housing 2 respectively. In a state where the connection terminals of the wires are electrically connected to the terminal portion 4 through the terminal screws 5, if the movable contact 32 and the fixed contact 42 are electrically connected, Connected, the wires are electrically conductive to each other. Thereby, the push-button switch 1 is turned on. From this state, when the pressing force of the plunger 3 is released, the elastic recovery of the compressed first coil spring 35 and the second coil spring 36 causes the plunger 3 to move upward, and the movable contact 32 and the fixed contact 42 are separated. . Thereby, the push-button switch 1 becomes an off state.

According to this embodiment, the one end portion 6a of the plate spring 6 is in surface contact with the washer 54 from the male thread portion 51 side and pushes the terminal screw 5 to the holding position P2. This allows the urging force of the leaf spring 6 to be imparted to the washer 54 in a more balanced manner. In addition, compared with the coil spring, the plate spring 6 can easily control the repelling direction when elastically returning from a bent state to a flat plate shape, and has good assembly properties. Therefore, according to the above structure, it is possible to provide a novel screw holding structure capable of holding the terminal screw 5 at the holding position P2 away from the terminal portion 4 without using a coil spring. In addition, the plate spring 6 is generally cheaper than the coil spring, and can help reduce the manufacturing cost of the push button switch 1 .

Furthermore, according to this embodiment, the terminal screw 5 includes the annular clamping member 55 that clamps the one end portion 6 a of the leaf spring 6 with the washer 54 . Thereby, the one end 6a of the leaf spring 6 can be firmly held between the washer 54 and the clamping member 55, and the urging force of the leaf spring 6 can be imparted to the washer 54 in a more balanced manner. In addition, since the washer 54 is interposed between the head 52 of the terminal screw 5 and the leaf spring 6, when the head 52 is rotated by the driver, the rotational force of the driver can be prevented from being directly applied to the leaf spring 6, thereby suppressing the The torsion of the leaf spring 6. Furthermore, on the male thread portion 51 side of the terminal screw 5, the clamping member 55 is interposed between the terminal portion 4 and the plate spring 6. Therefore, when the electric wire is inserted between the terminal portion 4 and the terminal screw 5, the electric wire and the plate can be suppressed from interposing. Spring 6 contacts.

Moreover, according to this embodiment, the groove part 27 into which the other end part 6b of the leaf spring 6 is inserted and holds the leaf spring 6 is provided in the housing 2. This can further improve assembly properties.

Furthermore, according to this embodiment, the restricting member 28 including the arc-shaped portion 28 a that restricts the bending amount of the leaf spring 6 is provided. Thereby, excessive bending of the leaf spring 6 can be suppressed by the restricting member 28 . For example, when the terminal screw 5 is located at the connection position P1 and the bending amount of the leaf spring 6 is increased, even if an external force or the like is applied to the housing 2 and an impact is applied to the leaf spring 6 , the bending of the leaf spring 6 can be suppressed. The amount further increases.

Furthermore, according to this embodiment, the washer 54 includes the first guide protrusion 56 protruding toward the head 52 side of the terminal screw 5, and the housing 2 includes the first guide groove in which the first guide protrusion 56 slides along the axial direction A1. Department 25. Thereby, the movement of the terminal screw 5 in the axial direction A1 can be restricted by the first guide protrusion 56 sliding in the first guide groove 25 , so that the urging force of the leaf spring 6 can be imparted to the washer 54 in a more balanced manner. . In addition, the first guide protrusion 56 slides on the first guide groove 25 to restrict the movement of the terminal screw 5 in the axial direction A1, so that the movement amount of the terminal screw 5 can be easily recognized.

Furthermore, according to this embodiment, the washer 54 includes the second guide protrusion 57 protruding toward the head 52 side at a position facing the first guide protrusion 56 across the head 52 when viewed from the axial direction A1. In addition, the housing 2 includes a second guide groove portion 26 for allowing the second guide protrusion 57 to move along the axial direction A1 when the terminal screw 5 moves between the connection position P1 and the holding position P2. Slide. Thereby, the movement of the terminal screw 5 in the axial direction A1 can be more reliably restricted by the first guide protrusion 56 and the second guide protrusion 57 sliding in the first guide groove 25 and the second guide groove 26 . Therefore, the urging force of the leaf spring 6 can be imparted to the washer 54 in a more balanced manner. In addition, the movement amount of the terminal screw 5 can be easily recognized, and visibility of whether the terminal screw 5 is located at the holding position P2 can be improved.

Furthermore, according to this embodiment, the washer 54 includes a protective member 58 protruding toward the head 52 side to prevent the leaf spring 6 from being exposed while the terminal screw 5 moves between the connection position P1 and the holding position P2. The movement path of the terminal screw 5 is concealed so that the leaf spring 6 is hidden. Thereby, when the driver is used to rotate the head 52 of the terminal screw 5 , the driver can be prevented from accidentally deviating from the movement path of the terminal screw 5 and coming into contact with the leaf spring 6 .

Furthermore, according to this embodiment, the protective member 58 is a protruding portion provided on the washer 54 so as to be located inside the housing 2 when the terminal screw 5 is located at the connection position P1, and project toward the housing when the terminal screw 5 is located at the holding position P2. 2's external protrusion. Thereby, when the terminal screw 5 is in the holding position P2, the protective member 58 protrudes to the outside of the housing 2. Therefore, the protective member 58 can be easily recognized at a glance, thereby improving visibility of whether the terminal screw 5 is in the holding position P2.

Furthermore, according to this embodiment, the protective member 58 is formed in a substantially rectangular plate shape having a longitudinal direction along the axial direction A1, so it can be arranged in a space-saving manner and is easy to manufacture.

In addition, the present invention is not limited to the above-described embodiment, and can be implemented in various other forms. For example, in the description, the screw connection structure of the present invention is provided on the push button switch 1, but the present invention is not limited thereto. The screw connection structure of the present invention can be applied to devices using the following wire connection method: using the terminal screw 5 to push the front end of the wire inserted into the housing 2 through the wire insertion opening 24 to the terminal portion 4 for electrical connection. Examples of such devices include electrical equipment such as operating switches and indicator lights, and terminal blocks.

Moreover, in the above description, the first guide protrusion 56, the second guide protrusion 57, and the protective member 58 are formed in a substantially rectangular plate shape, but the present invention is not limited to this. For example, the first guide protrusion 56 , the second guide protrusion 57 , and the protective member 58 may be formed in a rod shape such as a polygonal column.

Furthermore, in the above description, the protective member 58 functions as a display portion that provides different visual indicators when the terminal screw 5 is located at the connection position P1 and when it is located at the holding position P2, but the present invention is not limited thereto. For example, as shown in FIG. 7 , a display portion 7 having a different color or material from other portions may be provided at the lower end of the first guide groove portion 25 that forms part of the wall surface forming the movement path of the terminal screw 5 . According to this structure, when the terminal screw 5 is located at the connection position P1, the display portion 7 can be viewed from the outside of the housing 2. On the other hand, when the terminal screw 5 is located at the holding position P2, the display portion 7 cannot be viewed from outside the housing 2. Therefore, by confirming the color or material of the wall surface forming the movement path of the terminal screw 5, it is possible to confirm whether the terminal screw 5 is located at the holding position P2, thereby improving the visibility.

Furthermore, by appropriately combining any of the various embodiments described above, the respective effects can be exerted.

The present invention has been fully described in relation to the preferred embodiments with reference to the accompanying drawings, but various modifications or modifications will be apparent to those skilled in the art. It should be understood that such deformations or modifications are included in the scope of the present invention as long as they do not deviate from the scope of the appended patent application. [Industrial availability]

The screw holding structure of the present invention can provide a novel screw holding structure that can hold the terminal screw at a holding position away from the terminal portion without using a coil spring. Therefore, it is suitable for terminal blocks or electrical equipment that use a wire connection method using terminal screws. it works.

1: Press the button switch 2: Shell 3:Plunger 4:Terminal part 5:Terminal screw 6:leaf spring 6a: One end 6b: The other end 7:Display part 21:Front side shell assembly 22:Rear side shell assembly 23:Through hole 24:Wire insertion port 25: First guide groove part 26: Second guide groove part 27: Groove 28: Limit components 28a: Arc-shaped part 29:Boss 31: Front end 32: Movable contactor 33: Contact arm 34:Protrusion 35:First coil spring 36:Second coil spring 41:Female thread part 42:Fixed contact 51:Male thread part 52:Head 52a: Screw groove part 53:Neck 54: Washer 55: Clamping member 56: First guide protrusion 57: Second guide protrusion 58: Protective components A1: axis direction P1: connection position P2: Maintain position

FIG. 1 is a perspective view of a push button switch including a screw connection structure according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the push button switch of FIG. 1 . FIG. 3 is a perspective view showing a state in which the front case assembly is removed from the push-button switch of FIG. 1 . FIG. 4 is a perspective view showing a state in which the rear case assembly is removed from the push-button switch of FIG. 1 . FIG. 5 is a perspective view showing a state in which the plunger is further removed from the state shown in FIG. 4 . 6 is a perspective view of a terminal screw included in the screw connection structure according to the embodiment of the present invention. FIG. 7 is a plan view showing a modification of the display unit included in the push button switch of FIG. 1 .

1: Press the button switch

2: Shell

3:Plunger

4:Terminal part

5:Terminal screw

6:leaf spring

6a: One end

6b: The other end

21:Front side shell assembly

22:Rear side shell assembly

23:Through hole

24:Wire insertion port

25: First guide groove part

27: Groove

28: Limit components

28a: Arc-shaped part

31: Front end

32: Movable contactor

33: Contact arm

34:Protrusion

35:First coil spring

41:Female thread part

42:Fixed contact

51:Male thread part

52:Head

52a: Screw groove part

53:Neck

54: Washer

55: Clamping member

56: First guide protrusion

A1: axis direction

P1: connection position

P2: Maintain position

Claims (10)

A screw retaining structure including: shell; The terminal part is arranged in the housing and includes a female thread part; A terminal screw includes a male thread portion capable of being screwed into the female thread portion, a head portion having a diameter larger than that of the male thread portion, a neck portion connecting the male thread portion and the head portion along an axial direction, and an annular gasket arranged around the neck; and a leaf spring, arranged in the housing, and The terminal screw is configured to be movable within the housing between the following positions: a connection position in which the male thread portion is screwed into the female thread portion and is connected to the terminal portion; and a holding position. , separated from the terminal portion in the axial direction, The leaf spring is configured as follows: one end portion contacts the washer surface from the male thread portion side, and when the threaded engagement between the female thread portion and the male thread portion is released, the terminal screw is pushed to the desired position. to maintain the position. The screw holding structure according to claim 1, wherein the terminal screw includes an annular clamping member, and the clamping member clamps one end of the leaf spring between the washer. The screw holding structure according to claim 1 or claim 2, wherein a groove is provided in the housing, and the groove is for inserting the other end of the leaf spring to hold the leaf spring. The screw holding structure according to claim 1 or claim 2, including a restricting member located between the terminal screw and the other end of the leaf spring, and including an arc-shaped portion, the arc When the terminal screw moves from the holding position to the connecting position, the shaped portion contacts a portion between one end and the other end of the leaf spring to limit the bending amount of the leaf spring. The screw holding structure according to claim 1 or claim 2, wherein the washer includes a first guide protrusion protruding toward the head side of the terminal screw, The housing includes a first guide groove portion for the first guide protrusion to move along the terminal screw when the terminal screw moves between the connecting position and the holding position. axis sliding. The screw holding structure according to claim 5, wherein the washer includes a third protruding portion protruding toward the head side at a position facing the first guide protrusion across the head when viewed from the axial direction. Two guide protrusions, The housing includes a second guide groove portion for the second guide protrusion to move along the terminal screw when the terminal screw moves between the connecting position and the holding position. axis sliding. The screw holding structure according to claim 1 or claim 2, wherein the washer includes a protective member protruding toward the head side so that the terminal screw is in contact with the holding member at the connecting position. During movement between positions, the leaf spring is concealed to prevent the leaf spring from being exposed to the movement path of the terminal screw. The screw holding structure according to claim 7, wherein the protective member is formed in a rod shape or a substantially rectangular plate shape. A terminal block includes the screw holding structure as described in any one of claims 1 to 8. An electrical device includes the screw holding structure as described in any one of claims 1 to 8.