Switch unit and pressure switch

Abstract

The present invention provides a switch unit and a pressure switch that can make it difficult for stress to concentrate in the drive receiving portion of the contact plate when it receives a driving force. [Solution] The switch unit 13 includes a contact plate 135 that receives the movement of the operating rod 122 as a driving force to move the second contact 134 toward and toward the first contact 133, and the contact plate body 135a extends from a fixed end 135-1 to a free end 135-2, with the second contact 134 fixed to the free end 135-2, and a drive receiving part 135b-1 provided in the middle part 135-3 to receive the driving force, wherein the extended part 135a-2 of the contact plate body 135a is connected to the drive receiving part 135b-1 via a flat plate part, and the top of the folded part is located closer to the central axis X11 than the fixed end 135-1.

Description

Technical Field

[0001] The present invention relates to a switch unit that turns on / off upon receiving a driving force, and a pressure switch provided with such a switch unit.

Background Art

[0002] Conventionally, a pressure switch that turns on / off by separating one of a pair of contacts from the other by operating an operating rod in response to pressure fluctuations has been used. (For example, see Patent Document 1). In this pressure switch, a switch unit that turns on / off upon receiving the operation of the operating rod as a driving force is used. Many such switch units are configured to receive a driving force at an intermediate portion of a contact plate having a fixed end at the proximal end side and a contact fixed to the free end. When a driving force is received, the contact at the free end is pushed up. In the case of a normally open type, the pushed-up contact comes into contact with the counterpart contact and the switch is closed. In the case of a normally closed type, the pushed-up contact separates from the counterpart contact and the switch is opened.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in the above switch unit, in order to enhance the resistance to the large impact received by the contact plate during driving, and in order to ensure the contact pressure at the time of contact, a structure that enhances the rigidity of the contact plate may be adopted. However, if the rigidity of the contact plate is increased too much, stress when receiving the driving force tends to concentrate on the driving force receiving portion of the contact plate where the driving force is received, and there is a possibility that the durability of the driving force receiving portion is rather lowered.

[0005] Therefore, the present invention aims to provide a switch unit and a pressure switch that can make it difficult for stress to concentrate in the drive receiving portion of the contact plate when a driving force is received there, in view of the above-mentioned problems. [Means for solving the problem]

[0006] To solve the above problems, the switch unit comprises: a conductive first contact fixed one-to-one with one or more first terminals of a plurality of metal terminals; a conductive second contact electrically connected to one of the plurality of metal terminals and movable toward and toward the first contact; a conductive metal leaf spring extending from a fixed end fixed to the second terminal to a movable-to-movable position relative to the first contact, with the movable-to-movable position side being the free end, the second contact being fixed to the free end, and a contact plate that receives a driving force in the middle of the path from the fixed end to the free end, thereby moving the second contact in the same direction as the driving force relative to the first contact, thereby making the second contact move toward and toward the first contact; and a covered cylindrical frame portion, the plurality of metal terminals being attached through the lid portion, and the first contact, the second contact, and the contact plate being arranged inside, wherein the contact plate extends from the fixed end The device comprises a contact plate body extending to the free end, to which the second contact is fixed, and a drive receiving portion provided in the intermediate portion to receive the driving force, wherein the contact plate body has an extension portion between the fixed end and the intermediate portion that reaches the intermediate portion via a detour longer than the shortest path from the fixed end of the contact plate through the intermediate portion to the free end, the extension portion is formed in a bent shape via a folded portion that is folded back from one of two opposite directions to the other so as to be convex in the axial direction along the central axis of the body, the extension portion and the drive receiving portion are connected via a flat plate portion extending intersecting the axial direction, so that the extension portion is always separated from the member that applies the driving force to the drive receiving portion, the fixed end is a plate member extending in the axial direction, and the top of the folded portion is located closer to the central axis than the fixed end. Here, it is preferable that the extended portion is formed by connecting at least two extended portions that extend along the axial direction via the folded portion. Furthermore, it is preferable that the extended portion extends from the fixed end to a position beyond the shortest path on the side where the driving force is applied, and then returns to the shortest path via the folded portion which is folded back with that position as the top. Furthermore, it is preferable that the extended portion extends in an extension direction along the axial direction in which the plate member extends from the fixed end, passes through a folded portion which is folded back from the extension direction in an oblique direction inclined toward the central axis in the opposite direction to the extension direction, and is further bent in a direction intersecting the axial direction to connect to the flat plate portion. Furthermore, the switch unit comprises a conductive first contact fixed one-to-one to one or more first terminals of a plurality of metal terminals, a conductive second contact electrically connected to one of the plurality of metal terminals and movable toward and toward the first contact, a conductive metal leaf spring extending from a fixed end fixed to the second terminal to a movable position toward and toward the first contact with the movable position side as the free end, the second contact fixed to the free end, and a contact plate that receives a driving force in the middle of the path from the fixed end to the free end, thereby moving the second contact toward and toward the first contact in the same direction as the driving force, and a lidded cylindrical frame portion, the plurality of metal terminals attached through the lid, and the inside The device comprises a body on which a first contact, a second contact, and a contact plate are arranged, wherein the contact plate includes a contact plate body extending from a fixed end to a free end, with the second contact fixed to the free end, and a drive receiving plate on the opening side of the body relative to the contact plate body, fixed to the contact plate body on either the fixed end or the free end, and extending through the intermediate portion with the other side being unfixed, the intermediate portion being provided with a drive receiving portion that receives the driving force, and the other side being movable relative to the contact plate body in the extending direction of the contact plate body by bending, wherein the contact plate is characterized in that the second contact is brought into contact with and separated from the first contact while the flat plate portion of the contact plate body and the flat plate portion on the other side of the drive receiving plate remain overlapping.

[0007] According to the above-described switch unit, in a contact plate comprising a contact plate body and a drive receiving plate, the contact plate body and the drive receiving plate are overlapped from the fixed portion to the drive receiving portion to increase rigidity and ensure contact pressure when the contacts are in contact. On the other hand, because one side of the drive receiving plate is free, the stress generated in the drive receiving portion when a driving force is applied is appropriately distributed because the unfixed end of the drive receiving plate can move in accordance with the driving force. In this way, according to the above-described switch unit, it is possible to make it difficult for the stress when a driving force is applied to the drive receiving portion of the contact plate to concentrate in the drive receiving portion.

[0008] Here, the drive receiving plate may be superimposed on the contact plate body at the free end and fastened together with the second contact to the contact plate body.

[0009] In this configuration, the contact plate ensures stress distribution at the drive receiving section by using a drive receiving plate that is free on one side, while the rigidity is increased between the drive receiving section and the second contact by overlapping the drive receiving plate and the contact plate body. This increased rigidity in this section effectively suppresses bouncing and other issues during contact in the case of a normally open type where the second contact contacts the first contact after receiving the driving force.

[0010] Alternatively, the drive receiving plate may be superimposed on the contact plate body at the fixed end and fastened together with the second terminal to the contact plate body.

[0011] In this configuration, the contact plate ensures stress distribution at the drive receiving section by using a drive receiving plate that is free on one side, while rigidity is increased between the fixed end and the drive receiving section by overlapping the drive receiving plate and the contact plate body.

[0012] The improved rigidity in this section effectively suppresses stress at the point of deflection in the contact plate when a driving force is applied, especially in the case of a normally closed type where the second contact separates from the first contact when a driving force is applied. Furthermore, even when the switch unit is in the ON state before a driving force is applied, the drive support plate can restrain the driving force transmission member, such as the operating rod, thereby suppressing vibrations and the resulting wear of the transmission member.

[0013] Furthermore, the contact plate body is preferably made up of multiple plate members of the same shape stacked on top of each other, fastened together with the second terminal at the fixed end and fastened together with the second contact at the free end, and the drive receiving plate is preferably fastened together with the multiple plate members at either the fixed end or the free end.

[0014] With this configuration, by stacking thin plate-like members, a contact plate body with the desired strength, that is, a contact plate with the desired strength, can be effectively obtained.

[0015] Furthermore, it is preferable that the contact plate body has an extended portion between the fixed end and the intermediate portion, which reaches the intermediate portion via a detour longer than the shortest path from the fixed end of the contact plate through the intermediate portion to the free end.

[0016] With this configuration, an extended portion that is more flexible than the shortest path described above is provided between the fixed end and the intermediate portion of the contact plate body, so that the stress when a driving force is applied can be effectively distributed through this extended portion.

[0017] Furthermore, it is preferable that the shortest path is an L-shaped path that extends axially along the central axis of the body, bends once in a crossing direction, and then passes through the intermediate portion to the free end, when the driving force is received from the fixed end to the intermediate portion.

[0018] With this configuration, the extension follows a longer detour than the shortest L-shaped path. The shortest L-shaped path described above is the most natural path connecting the fixed end of the contact plate body, which is fixed to the second terminal on the lid side of the body, and the intermediate part that receives the driving force. However, by making the contact plate body follow a longer detour than this shortest path, a good detour can be established between the fixed end and the intermediate part.

[0019] In addition, it is preferable that the extension portion in the contact plate body follows a path that, as the bypass circuit, extends in the axial direction along the central axis of the body from the fixed end, bends more than twice, and then reaches the intermediate portion.

[0020] According to this configuration, the extension portion can be made longer, so the stress dispersion effect can be further improved.

[0021] In addition, in order to solve the above problems, the pressure switch includes the above-described switch unit and a drive unit that operates the operating rod in the axial direction along the central axis of the body in response to pressure fluctuations in the pressure space, and the contact plate receives the axial movement of the operating rod in the drive unit at the intermediate portion as the driving force.

[0022] According to the above pressure switch, since it includes the above-described switch unit, it is possible to make it difficult for the stress when the operating rod moves and the driving force is received at the drive receiving portion of the contact plate to concentrate on the drive receiving portion.

Effects of the Invention

[0023] According to the above switch unit and pressure switch, it is possible to make it difficult for the stress when the driving force is received at the drive receiving portion of the contact plate to concentrate on the drive receiving portion.

Brief Description of the Drawings

[0024] [Figure 1] It is a schematic diagram showing a normally open type pressure switch provided with the switch unit according to the first embodiment in an off state. [Figure 2] It is an enlarged view showing the contact plate and its surrounding structure in the pressure switch shown in FIG. 1. [Figure 3] It is a schematic diagram showing the pressure switch shown in FIG. 1 in an on state. [Figure 4] It is an enlarged view showing the contact plate and its surrounding structure in the pressure switch shown in FIG. 3. [Figure 5]This is a schematic diagram showing a normally closed type pressure switch equipped with a switch unit according to the second embodiment in the ON state. [Figure 6] Figure 5 is an enlarged view showing the contact plate and its surrounding structure in the pressure switch. [Figure 7] This is a schematic diagram showing a pressure switch equipped with a three-terminal type switch unit according to the third embodiment. [Figure 8] Figure 7 is an enlarged view showing the contact plate and its surrounding structure in the pressure switch. [Modes for carrying out the invention]

[0025] The following describes one embodiment of the switch unit and pressure switch. First, the first embodiment will be described.

[0026] Figure 1 is a schematic diagram showing a normally open type pressure switch equipped with a switch unit according to the first embodiment in the off state, and Figure 2 is an enlarged view showing the contact plate and its surrounding structure in the pressure switch shown in Figure 1. Furthermore, Figure 3 is a schematic diagram showing the pressure switch shown in Figure 1 in the on state, and Figure 4 is an enlarged view showing the contact plate and its surrounding structure in the pressure switch shown in Figure 3.

[0027] In this embodiment, the pressure switch 1 is a normally open type switch in which the conductivity state of a pair of metal terminals 131 is interrupted before the operation of the actuation rod 122, and transitions to the connected state after the operation of the actuation rod 122. This pressure switch 1 comprises a coupling 11, a drive unit 12, and a switch unit 13.

[0028] The joint 11 is the part to which a pipe through which pressurized fluid flows is connected, and which introduces the pressurized fluid into the pressure space 12a in the drive unit 12. The drive unit 12 is the part that moves the actuator rod 122 in the axial direction D11 in response to pressure fluctuations in the pressure space 12a, and comprises a diaphragm unit 121, actuator rod 122, annular member 123, O-ring 124, and connecting frame 125.

[0029] The diaphragm unit 121 is formed by sandwiching a disc-shaped diaphragm 121c between a cap 121a, which is a circular dish shape with a joint 11 connected to the center, and a disc-shaped stopper 121b, and then joining them at a coupling portion 121d on the outer circumference. In this diaphragm unit 121, the space partitioned by the cap 121a and the diaphragm 121c is the pressure space 12a, into which pressurized fluid is introduced via the joint 11. The diaphragm 121c reverses direction in response to pressure fluctuations of the pressurized fluid in this pressure space 12a. In this embodiment, at low pressures below a predetermined threshold, the diaphragm 121c has a concave shape recessed toward the cap 121a, and at high pressures exceeding the threshold, it reverses into a convex shape bulging toward the stopper 121b. The stopper 121b plays a role in limiting the bulging of the diaphragm 121c during reversal to a certain extent. A through hole 121b-1 is provided in the center of this stopper 121b for the operating rod 122 to pass through.

[0030] The operating rod 122 is a round rod member that is movable in the axial direction D11. It is installed so that one end abuts against the diaphragm 121c and the other end abuts against the contact plate 135 in the switch unit 13, passing through the through hole 121b-1 of the stopper 121b. When the diaphragm 121c is in a concave shape, the operating rod 122 is pushed down by the spring force of the contact plate 135. When the diaphragm 121c is reversed to a convex shape, the reversal pushes the operating rod 122 up in the upward direction D111, pushing up the contact plate 135 against the spring force.

[0031] The annular member 123 is positioned to overlap the stopper 121b and is an annular member with a cylindrical guide hole 123a in the center that penetrates along the axial direction D11. The operating rod 122 operates while being guided along the axial direction D11 by passing through this guide hole 123a. The O-ring 124 is an annular sealing member positioned to be sandwiched between the outer circumference of the annular member 123 and the outer circumference of the diaphragm unit 121, sealing the space between the annular member 123 and the diaphragm unit 121. The connecting frame 125 is a cylindrical frame member that crimps the drive unit 12, including the diaphragm unit 121, to the switch unit 13.

[0032] The switch unit 13 is the part that receives the operation of the actuarial rod 122 as a driving force and switches the conductive state of the pair of metal terminals 131 between an interrupted state and an connected state, and comprises the pair of metal terminals 131, a body 132, a first contact 133, a second contact 134, and a contact plate 135.

[0033] The pair of metal terminals 131 comprises a first terminal 131a, which is a metal strip extending along the axial direction D11, with one end bent in an L-shape toward the inside of the body 132, and a second terminal 131b, which is a straight strip positioned opposite the first terminal 131a.

[0034] The body 132 is a covered cylindrical frame portion, and a pair of metal terminals 131 are attached to it with their respective terminal portions protruding in a facing manner from the outer circumference, passing through the circular lid portion 132a. The body 132 also has a first contact 133, a second contact 134, and a contact plate 135 arranged inside it. The body 132 houses an annular member 123 through which the operating rod 122 passes on its opening 132b side, and the edge of the opening 132b is pressed against the outer circumference of the diaphragm unit 121 with an O-ring 124 in between, and is crimped to the drive unit 12 via a connecting frame 125.

[0035] The first contact 133 is a conductive contact member fixed to the first terminal 131a of a pair of metal terminals 131. The first contact 133 is crimped and fixed to the L-shaped bent portion 131a-1 of the first terminal 131a, with its contact surface with the second contact 134 facing the drive unit 12. Specifically, the crimped portion 133a of the first contact 133 is crimped and fixed by passing through and crushing the bent portion 131a-1. Note that the fixing of the first contact 133 is not limited to crimping, and various fixing methods such as welding and adhesive fixing with conductive adhesive can be used.

[0036] The second contact 134 is electrically connected to the second terminal 131b of the pair of metal terminals 131 via the contact plate 135, and is a conductive contact member that can move toward and away from the first contact 133. The second contact 134 is crimped to the end of the contact plate 135 via a crimping portion 134a similar to that of the first contact 133, with the contact surface of the second contact 134 facing the contact surface of the first contact 133. Note that the fixing of the second contact 134 is not limited to crimping, and various fixing methods such as welding and adhesive fixing with conductive adhesive can be used.

[0037] The contact plate 135 is a conductive metal leaf spring that extends from a fixed end 135-1 fixed to the second terminal 131b to a contact / separation position with respect to the first contact 133, with the contact / separation position side being the free end 135-2. The second contact 134 is fixed to the free end 135-2 of the contact plate 135, and one end of the operating rod 122 in the drive unit 12 abuts against an intermediate portion 135-3 of the path from the fixed end 135-1 to the free end 135-2. The contact plate 135 then receives the axial movement D11 of the operating rod 122 as a driving force at this intermediate portion 135-3, thereby causing the second contact 134 to make contact with the first contact 133.

[0038] In this embodiment, as shown in Figures 2 and 4, the contact plate 135 comprises a contact plate body 135a and a drive receiving plate 135b.

[0039] The contact plate body 135a extends from the fixed end 135-1 to the free end 135-2 of the contact plate 135, and the second contact 134 is fixed to the free end 135-2. The fixed end 135-1 side of the contact plate body 135a is fixed to the second terminal 131b, and this fixing is performed by a crimping portion 131b-1 provided at the end of the second terminal 131b on the body 132 side. This crimping portion 131b-1 penetrates the contact plate body 135a and is crushed, thereby crimping the fixed end 135-1 side of the contact plate body 135a to the second terminal 131b. Note that the fixing of the contact plate body 135a to the second terminal 131b is not limited to crimping, and various fixing methods such as welding and adhesive fixing with conductive adhesive can be used.

[0040] The drive support plate 135b is a member that is fixed to the contact plate body 135a at the free end 135-2 side of the contact plate body 135a on the opening 132b side of the body 132, i.e., on the operating rod 122 side. On the other hand, this drive support plate 135b extends from the free end 135-2 side via the intermediate portion 135-3, but the fixed end 135-1 side of the contact plate 135 is an unfixed, one-sided free plate member. The drive support plate 135b is provided with a drive support portion 135b-1 at the intermediate portion 135-3 that receives the movement of the operating rod 122. The portion of this drive support portion 135b-1 that abuts against one end of the operating rod 122 is a dowel, which is a non-penetrating protruding shape that is rounded and bulges out so as to form part of a spherical wall.

[0041] Furthermore, the drive receiving plate 135b is fastened together with the contact plate body 135a by the second contact 134 while being superimposed on the contact plate body 135a at the free end 135-2 side. In this embodiment, the contact plate body 135a is composed of two plate members 135a-1 of the same shape superimposed on each other. These two plate members 135a-1 are fastened together with each other at the fixed end 135-1 by the second terminal 131b, and at the free end 135-2 by the second contact 134. The drive receiving plate 135b is fastened together with the two plate members 135a-1 at the free end 135-2 side. Specifically, the crimping portion 134a of the second contact 134 penetrates the two plate members 135a-1 and the free end 135-2 side of the drive receiving plate 135b, and is crimped and fastened together. Furthermore, the specific fastening method for joint fastening is not limited to crimping; various fastening methods such as welding and adhesive fastening using conductive adhesives can be employed.

[0042] Here, the shortest path L1 from the fixed end 135-1 of the contact plate 135 to the free end 135-2 via the intermediate section 135-3 is as follows. That is, this shortest path L1 is an L-shaped path that extends from the fixed end 135-1 in the axial direction D11 along the central axis X1 of the body 132 when it receives driving force at the intermediate section 135-3, bends once in the intersecting direction D12, and then goes through the intermediate section 135-3 to the free end 135-2. In contrast, the contact plate body 135a of this embodiment has an extended section 135a-2 between the fixed end 135-1 and the intermediate section 135-3 that follows a longer detour than the shortest path L1 to reach the intermediate section 135-3. This extension 135a-2 follows a path that, as a detour as described above, extends from the fixed end 135-1 in the axial direction D11 along the central axis X1 of the body 132, bends twice, and then reaches the intermediate section 135-3. Specifically, the path followed by the extension 135a-2 extends from the fixed end 135-1 to a position beyond the shortest path L1 toward the drive unit 12, and then bends at that position to return to the shortest path L1 by bending diagonally. The extension 135a-2 is a curved section that bulges toward the drive unit 12 from beyond the shortest path L1 until it returns.

[0043] According to the switch unit 13 and pressure switch 1 of the first embodiment described above, the rigidity of the contact plate 135, which comprises a contact plate body 135a and a drive receiving plate 135b, is increased in the following locations. Specifically, in this contact plate 135, the contact plate body 135a and the drive receiving plate 135b are superimposed on each other from the fixed portion of the contact plate body 135a and the drive receiving plate 135b to the drive receiving portion 135b-1, thereby increasing rigidity. On the other hand, because the drive receiving plate 135b is free on one side, the stress generated in the drive receiving portion 135b-1 when the operating rod 122 is operated is appropriately distributed because the unfixed end of the drive receiving plate 135b can move in accordance with the operation of the operating rod 122. In this way, according to the switch unit 13 and pressure switch 1 described above, it is possible to make it difficult for the stress when the operating rod 122 is applied to the drive receiving portion 135b-1 of the contact plate 135 to concentrate in the drive receiving portion 135b-1.

[0044] In this embodiment, the drive support plate 135b is fastened together with the contact plate body 135a by the second contact 134 at the free end 135-2 side of the contact plate 135. With this configuration, the stress distribution effect at the drive support portion 135b-1 is ensured by the drive support plate 135b, which is free on one side of the contact plate 135. Furthermore, the rigidity of the contact plate 135 is increased by the overlapping of the drive support plate 135b and the contact plate body 135a between the drive support portion 135b-1 and the second contact 134.

[0045] In this case, in a normally open type such as the pressure switch 1 of this embodiment, unlike the above configuration, if the rigidity of the contact plate from the drive receiving part to the second contact is low, bouncing, in which the contacts repeatedly separate when contact is made, is likely to occur. Such bouncing is undesirable because it may cause contact wear.

[0046] In contrast, according to the configuration of this embodiment, the rigidity of the contact plate 135 from the drive receiving portion 135-1 to the second contact 134 is increased, so that bouncing can be effectively suppressed.

[0047] Furthermore, in this embodiment, the contact plate body 135a is made up of two plate members 135a-1 of the same shape that are stacked on top of each other and fastened together at both ends. The drive receiving plate 135b is fastened together with the two plate members 135a-1 at the free end 135-2 side. With this configuration, by stacking thin plate members 135a-1, a contact plate body 135a with the desired strength, and thus a contact plate 135 with the desired strength, can be effectively obtained.

[0048] Furthermore, in this embodiment, the shortest path L1 from the fixed end 135-1 of the contact plate 135 to the free end 135-2 via the intermediate portion 135-3 is an L-shaped path. The contact plate body 135a has an extension portion 135a-2 between the fixed end 135-1 and the intermediate portion 135-3 that follows a longer detour than this shortest path L1. With this configuration, the extension portion 135a-2 is provided between the fixed end 135-1 and the intermediate portion 135-3 of the contact plate body 135a, which is more flexible than when following the shortest path L1. This extension portion 135a-2 can effectively distribute the stress when subjected to movement from the operating rod 122.

[0049] Furthermore, in this embodiment, the extension portion 135a-2 follows a path that extends from the fixed end 135-1 in the axial direction D11, bends twice, and then reaches the intermediate portion 135-3, acting as the aforementioned detour. With this configuration, the extension portion 135a-2 can be made longer, thereby further improving the stress distribution effect.

[0050] Next, a second embodiment will be described. This second embodiment differs from the first embodiment described above in that the switch type is a normally closed type. In the following, the second embodiment will be described focusing on the differences from the first embodiment.

[0051] Figure 5 is a schematic diagram showing a normally closed type pressure switch equipped with a switch unit according to the second embodiment in the ON state, and Figure 6 is an enlarged view showing the contact plate and its surrounding structure in the pressure switch shown in Figure 5. In Figures 5 and 6, components equivalent to those of the first embodiment shown in Figures 1 and 2 are indicated only with the same reference numerals as in Figures 1 and 2, provided that they are necessary for explaining the second embodiment.

[0052] In this embodiment, the pressure switch 2 is a normally closed type switch in which the conductive state of a pair of metal terminals 231 is connected before the operation of the actuation rod 122, and transitions to a closed state upon the operation of the actuation rod 122. This pressure switch 2 includes a coupling 11 and drive unit 12 equivalent to those in the first embodiment, and a switch unit 23 having a slightly different structure due to the difference in switch type.

[0053] In the switch unit 23, contrary to the first embodiment, the first contact 233 is positioned closer to the drive unit 12 than the second contact 234. In the pair of metal terminals 231, in accordance with this contact arrangement, the L-shaped bent portion 231a-1 on the first terminal 231a, to which the first contact 233 is fixed, is positioned closer to the drive unit 12 than in the first embodiment.

[0054] The contact plate 235 is the same as in the first embodiment described above in that the second terminal 231b side is a fixed end 235-1, and it passes through an intermediate portion 235-3 that receives the movement of the operating rod 122, and reaches a free end 235-2 to which the second contact 234 is fixed. On the other hand, the shape of the contact plate body 235a and the drive receiving plate 235b that constitute this contact plate 235 differs from that of the first embodiment.

[0055] First, the contact plate body 235a does not have a portion corresponding to the extension portion 135a-2 in the first embodiment, and is an L-shaped plate member that extends from the fixed end 235-1 in the axial direction D11 and bends only once in the intersecting direction D12, following a substantially shortest path. Also, unlike the first embodiment, the contact plate body 235a has a single plate structure. Furthermore, its free end 235-2 side is lifted towards the circular lid side so that the second contact 234 rests on top of the first contact 233 and is slightly lifted. Before the operation of the operating rod 122, the contact plate body 235a presses the second contact 234 against the first contact 233 due to the reaction force from this lifting.

[0056] Next, the drive support plate 235b is a thin metal plate that extends in an L-shape, approximately the same shape as the contact plate body 235a, from the fixed end 235-1 to a position slightly beyond the intermediate portion 235-3. At the fixed end 235-1, the drive support plate 235b is superimposed on the contact plate body 235a and is fastened together with the contact plate body 235a by the second terminal 231b. However, before the operation of the operating rod 122, the contact plate body 235a is lifted at the free end 235-2, so the drive support plate 235b and the contact plate body 235a are open so that the opening dimension gradually increases from the L-shaped bend to the intermediate portion 235-3. The drive support plate 235b is a plate member that is not fixed to the contact plate body 235a at the free end 235-2, and is free on one side. The intermediate portion 235-3 of the drive support plate 235b is provided with a drive support portion 235b-1 that receives the movement of the operating rod 122. This drive support portion 235b-1 is a dowel, similar to that of the first embodiment.

[0057] When the actuator rod 122 is operated, the actuator rod 122, which is pushed up in the upward direction D111, pushes up the drive receiving plate 235b and makes contact with the contact plate body 235a, and further pushes up both, i.e., the contact plate 235, thereby separating the second contact 234 from the first contact 233. As a result, the conductive state of the pair of metal terminals 231 transitions from a connected state to a disconnected state.

[0058] It goes without saying that, as with the first embodiment described above, the switch unit 23 and pressure switch 2 of the second embodiment also make it difficult to concentrate the stress on the drive receiving portion 235b-1 of the contact plate 235 when it receives the movement of the operating rod 122.

[0059] Furthermore, in this embodiment, the drive support plate 235b is fastened together with the contact plate body 235a at the second terminal 231b on the fixed end 235-1 side. With this configuration, the stress distribution effect at the drive support portion 235b-1 is ensured by the drive support plate 235b, which is free on one side of the contact plate 235. In addition, the rigidity is increased between the fixed end 235-1 and the drive support portion 235b-1 by the overlapping of the drive support plate 235b and the contact plate body 235a.

[0060] In this case, in a normally closed type such as the pressure switch 2 of this embodiment, there is nothing to prevent the deformation of the contact plate 235 when it is subjected to an impact from the operating rod 122, so the contact plate 235 will bend as it is pressed by the operating rod 122. Unlike the above configuration, in such a normally closed type, if the rigidity between the fixed end, which is the starting point of the deflection of the contact plate, and the drive receiving part is low, the stress at the starting point of the deflection of the contact plate tends to become large, which is undesirable.

[0061] In contrast, according to the configuration of this embodiment, the rigidity of the contact plate 235 is increased from the fixed end 235-1 to the drive receiving portion 235b-1, so that the stress at the starting point of deflection in the contact plate 235 can be effectively suppressed. Furthermore, even when the pressure switch 2 is ON before the operation of the operating rod 122, the operating rod 122 can be held down by the drive receiving plate 235b, thereby suppressing the movement of the operating rod 122 due to vibration and the resulting wear of the components.

[0062] Next, a third embodiment will be described. This third embodiment differs from the first embodiment described above in that the switch unit is provided with three metal terminals. In the following, the third embodiment will be described focusing on the differences from the first embodiment.

[0063] Figure 7 is a schematic diagram showing a pressure switch equipped with a three-terminal type switch unit according to the third embodiment. Figure 7 shows a top view of the pressure switch 3 as seen from the metal terminal 331 side, and a cross-sectional view along the line V31-V31 in the top view side by side. Figure 8 is an enlarged view showing the contact plate and its surrounding structure in the pressure switch shown in Figure 7. In Figures 7 and 8, components equivalent to those of the first embodiment shown in Figures 1 and 2 are indicated with the same reference numerals as in Figures 1 and 2, but only those necessary for explaining the third embodiment are indicated.

[0064] In this embodiment, the pressure switch 3 switches the conductivity state of three metal terminals 331 in response to the operation of the operating rod 122. That is, the connection destination of one second terminal 331c is switched between two first terminals 331a and 331b. In the example shown in Figures 7 and 8, the second terminal 331c is connected to one first terminal 331b and disconnected from the other first terminal 331a. This pressure switch 3 includes a coupling 11 and drive unit 12 equivalent to those in the first embodiment, and a switch unit 33 of a different switch type.

[0065] In the switch unit 33, the three metal terminals 331 each have two first terminals 331a and 331b, which are metal strips extending along the axial direction D11, with one end of each strip bent in an L-shape toward the inside of the body 332. The three metal terminals 331 also have one second terminal 331c, which is a straight strip and is positioned opposite these two first terminals 331a and 331b toward the central axis X3 of the body 332. Near the outer circumference of the circular lid of the covered cylindrical body 332, the terminal portions of each of the three metal terminals 331 protrude so as to face the central axis X3 of the body 332.

[0066] The two first contacts 333a and 333b are conductive contact members fixed one-to-one to two of the three metal terminals 331, namely first terminals 331a and 331b. The two first contacts 333a and 333b are fixed to the internal parts of the body 332 of the two first terminals 331a and 331b, facing each other with a range of motion along the axial direction D11 of one second contact 334. The first contact 333b furthest from the circular cover is fixed to a cantilever-shaped flexible plate 331b-1 provided on one of the first terminals 331b. An adjustment screw 336, which can move back and forth in the axial direction D11, is positioned on the drive unit 12 side of this first contact 333b, and its tip abuts against the first contact 333b. As this adjustment screw 336 moves forward and backward, one of the first contacts 333b is moved in the axial direction D11, and the range of motion of the second contact 334 between the two opposing first contacts 333a and 333b is adjusted.

[0067] One second contact 334 is electrically connected to one of the three metal terminals 331, specifically the second terminal 331c, via a contact plate 335, and is a conductive contact member that can connect to and disconnect from the two first contacts 333a and 333b.

[0068] The contact plate 335 has a shape that is generally similar to the contact plate 235 of the second embodiment. That is, the contact plate 335 has a fixed end 335-1 on the second terminal 331c side, passes through an intermediate portion 335-3 that receives the movement of the operating rod 122, and reaches a free end 335-2 to which the second contact 334 is fixed. This contact plate 335 comprises a contact plate body 335a and a drive receiving plate 335b.

[0069] First, the contact plate body 335a has an L-shape similar to the contact plate body 235a of the second embodiment, but unlike the second embodiment, it is composed of two plate members 335a-1 of the same shape superimposed on each other. These two plate members 335a-1 are fastened together at the fixed end 335-1 by the second terminal 331c, and at the free end 335-2 by the second contact 334.

[0070] The drive support plate 335b is a member that is fixed to the contact plate body 335a at the free end 335-2 side of the contact plate body 335a on the operating rod 122 side relative to the contact plate body 335a. On the other hand, the fixed end 335-1 side of this drive support plate 335b is a plate member that is free on one side and not fixed to the contact plate body 335a. The drive support plate 335b is provided with a drive support portion 335b-1 that receives the movement of the operating rod 122 at the intermediate portion 335-3. This drive support portion 335b-1 is a dowel similar to that of the first embodiment.

[0071] Before the actuation rod 122 is operated, the drive receiving plate 335b is pressed so that its drive receiving portion 335b-1 separates from the contact plate body 335a and pushes down the tip of the actuation rod 122. At this time, as shown in Figures 7 and 8, the second contact 334 is separated from one of the first contacts 333a and in contact with the other first contact 333b. As a result, before the actuation rod 122 is operated, one of the second terminals 331c is disconnected from one of the first terminals 331a and connected to the other first terminal 331b.

[0072] When the actuator rod 122 is operated, the actuator rod 122, which is pushed up in the upward direction D111, pushes up the drive receiving plate 335b and makes contact with the contact plate body 335a, and further pushes up both, i.e., the contact plate 335. As a result, the second contact 334 is separated from the other first contact 333b and comes into contact with the first contact 333a. Consequently, the connection destination of one second terminal 331c is switched from the other first terminal 331b to the first first terminal 331a.

[0073] It goes without saying that, as with the first embodiment described above, the switch unit 33 and pressure switch 3 of the third embodiment also make it difficult to concentrate the stress on the drive receiving portion 335b-1 of the contact plate 335 when it receives the movement of the operating rod 122, as is the case with the third embodiment described above.

[0074] Furthermore, the first to third embodiments described above merely represent typical forms of the switch unit and pressure switch, and the switch unit and pressure switch are not limited to these and can be implemented in various modified forms.

[0075] For example, in the first to third embodiments described above, a drive unit 12 is provided as an example of a drive unit, which moves the actuator rod 122 in the axial direction D11 using a diaphragm unit 121. However, the drive unit is not limited to this, and any specific drive source can be adopted as long as it moves the actuator rod in the axial direction in response to pressure fluctuations in the pressure space.

[0076] Furthermore, in the first and third embodiments described above, as an example of a contact plate, contact plates 135 and 335 are shown in which the drive support plates 135b and 335b are fastened together with the contact plate bodies 135a and 335a at the free ends 135-2 and 335-2. Also, in the second embodiment described above, as an example of a contact plate, contact plate 235 is shown in which the drive support plate 235b is fastened together with the contact plate body 235a at the fixed end 235-1. However, the contact plate is not limited to any of these, and any of the two forms described above may be used as long as the drive support plate is fixed to the contact plate body on either the fixed end or the free end. However, as described above, the contact plate 135 of the first embodiment is effective in suppressing bouncing in a normally open type, and the contact plate 235 of the second embodiment is effective in suppressing stress on the deflection initiation side in a normally closed type.

[0077] Furthermore, in the first and third embodiments described above, as an example of a contact plate body, a contact plate body 135a, 335a is provided in which two plate members 135a-1, 335a-1 of the same shape are superimposed and fastened together at both ends. However, the contact plate body is not limited to this, and may be a single-plate structure as illustrated in the second embodiment. However, as described above, using a contact plate body 135a, 335a made by superimposing plate members 135a-1, 335a-1 makes it possible to effectively obtain a contact plate 135, 335 with the desired strength. Even when the contact plate body is constructed by superimposing plate members, the number of superimposed plates is not limited to two, and any number can be used.

[0078] Furthermore, in the first embodiment described above, as an example of a contact plate body, a contact plate body 135a having an extension portion 135a-2 between the fixed end 135-1 and the intermediate portion 135-3 that receives movement from the operating rod 122 is exemplified. In this example, the extension portion 135a-2 follows a two-bend detour that is longer than the L-shaped shortest path L1. However, the contact plate body is not limited to this, and as exemplified in the second and third embodiments, it may not have an extension portion and may extend substantially along the shortest path. However, as described above, the contact plate body 135a having an extension portion 135a-2 allows for effective distribution of stress when subjected to movement from the operating rod 122. Furthermore, as described above, by making the extension portion 135a-2 follow a two-bend detour, the extension portion 135a-2 can be effectively formed by bending the plate member or the like. Furthermore, the detour route followed by the extension is not limited to a path with two bends; any path that extends axially from the fixed end and bends two or more times can be set appropriately. [Explanation of symbols]

[0079] 1,2,3 Pressure switch 11 Fittings 12 Drive Unit 12a Pressure space 13, 23, 33 Switch Unit 121 Diaphragm Unit 121a Cap 121b Stopper 121b-1 Passing hole 121c diaphragm 121d Joint 122 Actuating rod 123 Annular member 124 O-rings 125 Connecting Frame 131,231,331 Metal terminal 131a,231a,331a,331b 1st terminal 131a-1, 231a-1 Folded section 131b,231b,331c 2nd terminal 131b-1, 133a, 134a Crimping section 132,332 bodies 132a Circular lid 132b aperture 133,233,333a,333b 1st contact 134,234,334 Second contact point 135,235,335 Contact plate 135-1,235-1,335-1 Fixed end 135-2,235-2,335-2 Free end 135-3,235-3,335-3 Middle part 135a, 235a, 335a Contact plate body 135a-1,335a-1 Plate member 135a-2 Extension 135b, 235b, 335b Drive support plate 135b-1, 235b-1, 335b-1 Drive receiver 336 Adjustment Screw D11 Axial direction D12 Intersecting direction D111 Push-up direction L1 Shortest Path X1,X3 center axis

Claims

1. A conductive first contact is fixed one-to-one to one or more first terminals among a plurality of metal terminals, A conductive second contact is electrically connected to one of the plurality of metal terminals, and is movable toward and from the first contact. A conductive metal plate spring extending from a fixed end fixed to the second terminal to a contact / separation position relative to the first contact, with the contact / separation position side being the free end, wherein the second contact is fixed to the free end, and a contact plate that receives a driving force in the middle of the path from the fixed end to the free end, thereby moving the second contact in the same direction as the driving force relative to the first contact, thereby causing the second contact to make contact with and separate from the first contact, The device comprises a lidded cylindrical frame portion, through which the plurality of metal terminals are attached, and a body in which the first contact, the second contact, and the contact plate are arranged inside, The aforementioned contact plate, A contact plate body extending from the fixed end to the free end, with the second contact fixed to the free end, The vehicle comprises a drive receiving portion provided in the middle portion to receive the driving force, The contact plate body has an extended portion between the fixed end and the intermediate portion, which reaches the intermediate portion by following a detour that is longer than the shortest path from the fixed end of the contact plate through the intermediate portion to the free end. The extension portion is formed in a bent shape by passing through a folded portion that is folded back from one of two opposite directions to the other, so as to be convex in the axial direction along the central axis of the body, and the extension portion and the drive receiving portion are connected to the drive receiving portion via a flat plate portion that extends intersecting the axial direction, so that the extension portion is always separated from the member that applies the driving force to the drive receiving portion. A switch unit characterized in that the fixed end is a plate member extending in the axial direction, and the top of the folded portion is located closer to the central axis than the fixed end.

2. The switch unit according to claim 1, characterized in that the extension portion is formed by connecting at least two extending portions that extend along the axial direction via the folded portion.

3. The switch unit according to claim 1, characterized in that the extended portion extends from the fixed end to a position beyond the shortest path on the side to which the driving force is applied, and returns to the shortest path via the folded portion which is folded back with that position as the top.

4. The switch unit according to claim 1, characterized in that the extended portion extends in an extension direction along the axial direction in which the plate member extends from the fixed end, passes through a folded portion which is folded back from the extension direction in an oblique direction inclined toward the central axis in the opposite direction to the extension direction, and is further bent in a direction intersecting the axial direction to connect to the flat plate portion.

5. A switch unit according to any one of claims 1 to 4, The system includes a drive unit that moves an operating rod axially along the central axis of the body in response to pressure fluctuations in a pressure space, A pressure switch characterized in that the contact plate receives the axial movement of the operating rod in the drive unit as the driving force at the intermediate portion.

Images