Microswitch and pressure-activated switch

Abstract

To provide a microswitch and a pressure-activated switch that can improve sealing performance.SOLUTION: A microswitch 1 includes a case 10 having an opening 28 that opens in a predetermined direction, a plurality of contacts 30 housed in the case 10, switching means 40 that switches the conductive state of the contacts 30, a cover 50 that covers the opening 28, an operating shaft 70 that is provided on the cover 50 and passes through the cover 50 to extend inside and outside the case 10, and a seal member S that is interposed between the case 10 and the cover 50 and is capable of sealing the opening 28. The cover 50 is provided with a lever 90 that transmits external force to move the operating shaft 70 back and forth in the axial direction.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a microswitch and a pressure-responsive switch.

Background Art

[0002] Conventionally, a microswitch (mechanical switch) that switches the conduction state of a plurality of contacts has been known (see, for example, Patent Document 1). As shown in FIG. 1 of Patent Document 1, the microswitch described in Patent Document 1 includes a housing 1 (case) that houses a plurality of contacts (2a, 4, 9), and a leaf spring 3 (switching means) that switches the conduction state of the contacts (2a, 4, 9) within the housing 1. Further, the microswitch includes a switch cover 11 (cover) that covers the opening of the housing 1, a pressing piece 5 (operating shaft) that is inserted through a hole formed in the switch cover 11, and a switch lever 6 (transmission member) that supports the pressing piece 5 outside the switch cover 11. A side wall that is a part of the housing 1 extends from the inside of the housing 1 to cross the switch cover 11 and extend to the outside of the housing 1. The switch lever 6 is rotatably supported around a support shaft of a support member 10 fixed to the side wall outside the housing 1. In this microswitch, when an external force is applied, the switch lever 6 rotates around the support shaft. When the switch lever 6 rotates, the pressing piece 5 moves forward and backward in the axial direction along with the rotation. Then, the leaf spring 3 is deformed by the forward and backward movement of the pressing piece 5, and the switching operation of the contacts (2a, 4, 9) is performed by the deformation of the leaf spring 3. As a result, the conduction state of the contacts (2a, 4, 9) is switched.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the conventional microswitch as described above, depending on the environment in which it is used, there may be a need to further prevent foreign matter from entering the case or to enhance the sealing performance of the case in order to stably perform the switching operation of the contacts. In this case, for example, it is conceivable to seal between the case and the cover with an adhesive or the like. However, in this configuration, since a process for applying the adhesive and a process for drying the adhesive are required, the man-hours and the manufacturing time for manufacturing the microswitch increase. On the other hand, it is also conceivable to interpose a sealing member separate from the case and the cover between the case and the cover. In this case, for example, it is conceivable to dispose the sealing member between the open end face of the case and the inner surface of the cover. However, in the conventional microswitch as described above, the side wall that supports the transmission member intersects the cover and extends to the outside. For this reason, since it is necessary to consider sealing around the side wall, it is not easy to set the sealing portion of the sealing member, and simply interposing the sealing member between the open end face of the case and the inner surface of the cover results in insufficient sealing and easily deteriorates the sealing performance.

[0005] An object of the present invention is to provide a microswitch and a pressure-responsive switch capable of improving the sealing performance.

Means for Solving the Problems

[0006] In order to solve the above problems and achieve the object, the microswitch of the present invention includes a case having an opening that opens in a predetermined direction, a plurality of contacts housed in the case, switching means for switching the conduction state of the contacts, a cover that covers the opening, an operating shaft provided on the cover and extending through the cover to the inside and outside of the case, and a sealing member interposed between the case and the cover and capable of sealing the opening, and is characterized in that a transmission member for advancing and retreating the operating shaft in the axial direction by transmitting an external force is provided on the cover.

[0007] According to such an aspect of the present invention, by providing the transmission member and the operating shaft on the cover, the cover, the operating shaft, and the transmission member can be integrated. As a result, it is not necessary to provide the case with a portion that makes it difficult to set the sealing location of the seal member, such as a side wall that intersects the cover and extends inside and outside the case. Therefore, for example, the opening can be sealed by providing a seal member along the opening end face of the case, and the sealing performance can be improved. Accordingly, it is possible to provide a microswitch capable of improving the sealing performance.

[0008] In addition, according to this configuration, since it is not necessary to provide the case with a side wall or the like that intersects the cover and extends inside and outside the case as described above, the shape of the opening of the case can be set to a relatively simple shape, such as a quadrangle or a circle. For this reason, the shape of the seal member can also be a simple shape, and the molding and attachment of the seal member can be facilitated. Thereby, it is possible to provide a microswitch that can easily improve the sealing performance at low cost.

[0009] Also, at this time, it is preferable that the case and the cover are provided with displacement restricting means for suppressing displacement relative to each other. In a device equipped with a microswitch, the position of the transmission member may deviate from the designed position due to an assembly error between the case and the cover. Also, depending on the usage environment or the like, for example, due to vibration, impact, or heat load, the positions of the case and the cover may shift relative to each other, causing the position of the transmission member to deviate from the designed position. In this case, the transmission of the external force by the transmission member may vary among products or may not be accurately performed due to displacement during use, resulting in an unstable contact switching operation. This has a particularly significant impact when a microswitch is mounted on a pressure responsive switch or the like that detects the pressure of a refrigerant in a refrigeration cycle or the like. The pressure responsive switch is not a device that forcibly transmits an external force to the operating shaft by operating the transmission member with a user's finger or the like, but is a device configured such that the transmission member and the operating shaft operate in response to a predetermined pressure (external force). In this device, a deviation in the position of the transmission member means that accurate pressure detection cannot be performed. However, according to this configuration, the displacement restricting means can suppress the positions of the case and the cover from shifting relative to each other. Therefore, the position of the transmission member is suppressed from shifting, and the transmission of the external force can be accurately performed. Accordingly, the operating stability of the microswitch can be further improved.

[0010] Further, the seal member is disposed between the opening end surface at the opening portion and the opposing surface of the cover that faces the opening end surface. The displacement restricting means is preferably composed of abutting portions provided on the opening end surface and the opposing surface that can abut against each other. For example, the seal member may be disposed around the entire circumference of the opening of the case and may be interposed between the case and the cover. In this configuration, for example, as the transmission member operates, the cover sinks toward the opening side while elastically deforming the seal member, and the elastic force of the seal member may cause the positions of the case and the cover to shift relative to each other, and the position of the transmission member may deviate from the position at the time of design. In this case, the external force cannot be accurately transmitted by the transmission member, and it is difficult to maintain the operating stability of the microswitch as described above. However, according to this configuration, the displacement restricting means is composed of abutting portions provided on the opening end surface and the opposing surface that can abut against each other. Therefore, even if the seal member is disposed around the entire circumference of the opening and interposed between the case and the cover, the displacement of the cover toward the opening side is prevented by at least a part of the abutting portions abutting against each other. Accordingly, the displacement of the transmission member is suppressed, and the external force can be accurately transmitted by the transmission member.

[0011] Further, the displacement restricting means includes a protrusion protruding from one of the case and the cover in the opening direction of the opening portion, and a restricting portion provided on the other of the case and the cover. The restricting portion is provided facing a crossing direction that intersects the opening direction, and it is preferable that the displacement of the protrusion in the crossing direction is restricted by the restricting portion. According to such a configuration, by restricting the displacement of the protrusion in the crossing direction by the restricting portion, it is possible to prevent the positions of the case and the cover from shifting relative to each other. Therefore, the operating stability of the microswitch can be improved. Note that the restricting portion may be a portion where the protrusion directly or indirectly abuts, or may be a recess or a hole into which the protrusion fits. Further, the restricting portion may be provided so as to make point contact, line contact, or surface contact with the protrusion in the crossing direction.

[0012] Further, it is preferable that the protrusion is provided on the cover, and the restricting portion is formed on the inner surface of the case. According to such a configuration, by forming the restricting portion on the inner surface of the case, for example, it is not necessary to form a recess or the like for fitting the protrusion into the case, and the structure of the case can be simplified.

[0013] Further, the protrusions preferably include independent first and second protrusions, and the restricting portion preferably includes a first restricting portion that restricts displacement of the first protrusion in a first direction among the intersecting directions, and a second restricting portion that is provided independently of the first restricting portion and restricts displacement of the second protrusion in a second direction intersecting the first direction among the intersecting directions. According to such a configuration, for example, when the first direction is the front-rear direction, by restricting the displacement of the first protrusion in the front-rear direction by the first restricting portion, the positions of the case and the cover can be restricted from shifting in the front-rear direction relative to each other. Also, when the second direction is the left-right direction, by restricting the displacement of the second protrusion in the left-right direction by the second restricting portion, the positions of the case and the cover can be restricted from shifting in the left-right direction relative to each other. Further, by providing the first protrusion, the second protrusion, the first restricting portion, and the second restricting portion independently of each other, the degree of freedom in arranging the displacement restricting means is improved, so that the influence of the displacement restricting means on the shapes of the case and the cover can be reduced.

[0014] Further, the displacement restricting means is a snap fit portion including an engaging portion disposed on one of the case and the cover and an engaged portion disposed on the other of the case and the cover, and it is preferable that displacement of the case and the cover in the opening direction of the opening is restricted in a state where the engaging portion and the engaged portion are engaged with each other. According to such a configuration, the snap fit portion can restrict the positions of the case and the cover from shifting in the opening direction relative to each other. Therefore, the operating stability of the microswitch can be improved.

[0015] Further, the engaging portion includes a base end portion, an elastic portion that extends from the base end portion in the opening direction and elastically deforms in an intersecting direction that intersects the opening direction, and a claw portion that protrudes from the elastic portion in the intersecting direction. The engaged portion preferably includes a restricting portion that restricts displacement of the base end portion in the intersecting direction and a locking portion that locks the claw portion. According to such a configuration, the position of the case and the cover can be restricted from shifting in the opening direction with respect to each other by the claw portion of the engaging portion being locked to the locking portion of the engaged portion. Further, since the displacement of the base end portion of the engaging portion in the intersecting direction is restricted by the restricting portion of the engaged portion, the position of the case and the cover can also be restricted from shifting in the intersecting direction with respect to each other. Therefore, the operating stability of the microswitch can be further improved.

[0016] Further, the displacement restricting means may be constituted by a screw portion that fixes the case and the cover. According to this configuration, by fixing the case and the cover with the screw portion, the positions of the case and the cover can be restricted from shifting in the opening direction and the intersecting direction with respect to each other.

[0017] Further, the pressure-responsive switch of the present invention is characterized by including the microswitch according to any one of the above. According to such a present invention, a pressure-responsive switch can be provided using a microswitch capable of improving the sealing performance.

Effects of the Invention

[0018] According to the present invention, a microswitch and a pressure-responsive switch capable of improving the sealing performance can be provided.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0020] Hereinafter, an embodiment of the present invention will be described. The microswitch 1 according to this embodiment is mounted on, for example, a pressure-responsive switch 100 that detects a change in the pressure or temperature of a fluid, and detects, for example, a change in the pressure or temperature of a fluid used as a working medium for actuators such as a refrigeration cycle, an automobile, and various control devices.

[0021] In the following description, in the drawings, the horizontal direction (the crossing direction in the present invention) is indicated by arrows X and Y, and is denoted as "left-right direction X" and "front-rear direction Y", respectively. One side of the left-right direction X is denoted as "left side X1", the other side is denoted as "right side X2", one side of the front-rear direction Y is denoted as "front side Y1", and the other side is denoted as "rear side Y2". Note that the front-rear direction Y is the first direction in this embodiment, and the left-right direction X is the second direction in the present invention. Also, the opening direction of the case 10 described later is indicated by an arrow Z and is denoted as "vertical direction Z". One side of the vertical direction Z is denoted as "lower side Z1", and the other side is denoted as "upper side Z2". The vertical direction Z is orthogonal (crosses) to the left-right direction X and the front-rear direction Y. These definitions of directions are for convenience of explanation only, and do not necessarily match the directions in the actual use state of the microswitch 1, and do not limit the respective directions in the actual use state of the microswitch 1.

[0022] As shown in FIG. 1, the pressure-responsive switch 100 includes a housing 110 that is generally rectangular in shape as a whole. The housing 110 is configured to include a C-shaped main body frame 111 that opens downward at Z1 and a lid portion (not shown) that closes the opening of the main body frame 111, and houses various components such as a microswitch 1 and the like described later inside. The main body frame 111 is formed by bending a metal plate material or the like, and includes a front wall portion 112, a side wall portion 113, a rear wall portion 114, and a top wall portion 115. A pair of elements 116 and a pair of joint pipes 117 respectively connected to the pair of elements 116 are connected to the rear wall portion 114 of the housing 110. The element 116 includes a sensitive member such as a bellows or a diaphragm (not shown) inside. The sensitive member deforms or displaces in the front-rear direction Y in response to a change in the pressure of the pressure fluid introduced through the joint pipe 117.

[0023] Inside the housing 110, a pair of left and right transmission mechanisms 118 and a pair of left and right switch components 119 are housed. The transmission mechanism 118 includes a reinforcing plate 120 formed in a C shape that opens upward at Z2 by bending a metal plate material or the like, and houses a transmission portion 121 inside the reinforcing plate 120. As an example of the transmission portion 121, for example, it is an operating plate 122. The operating plate 122 receives, as an external force, a force such as the force by which the above-described sensitive member deforms or displaces, and converts the external force into an operating force by rotating around a rotation shaft 123, and transmits the operating force to a lever 90 described later. The switch component 119 is configured to include a plurality of contacts 30 described later, and switches the conduction state of the contacts 30 in response to the above-described operating force. The switch components 119 are provided in a pair adjacent to each other in the left-right direction X and constitute a dual-type microswitch 1.

[0024] As shown in FIG. 2, the microswitch 1 includes a case 10 (terminal block body) and a cover 50 disposed on the upper side Z2 of the case 10. First, the case 10 will be described. The case 10 is formed in a substantially cubic box shape using, for example, a resin material. As shown in FIG. 3, the case 10 includes a bottom plate 11 in the shape of a rectangular plate. At the front end of the bottom plate 11, a front wall 12 rising upward in the upper side Z2 is formed. The front wall 12 is formed, for example, in the shape of a rectangular plate, and a mounting hole 13 penetrating in the vertical direction Z is formed on its upper end surface. A reset shaft constituting a manual reset mechanism (not shown) is inserted into the mounting hole 13. At the lower end portion of the front wall 12, a concave button housing portion 14 opening to the front side Y1 and the lower side Z1 is formed. The button housing portion 14 houses a reset button attached to the end portion of the reset shaft.

[0025] A pair of side walls 15 rising upward in the upper side Z2 are formed at both the left and right ends of the bottom plate 11. The side walls 15 are formed, for example, in the shape of rectangular plates. The front ends of the side walls 15 and the left and right ends of the front wall 12 are connected to form a front corner portion 16. A rear wall 17 extending in the left - right direction X is formed between the rear end portions of the side wall 15 on the left side X1 and the side wall 15 on the right side X2. The rear wall 17 is formed, for example, in the shape of a rectangular plate. A part of the rear wall 17 bulges toward the rear side Y2, and this bulging portion constitutes a connection portion 18 when the microswitch 1 is attached to the housing 110. A first screw hole 18a penetrating in the vertical direction Z is formed at the center of the connection portion 18. A fixing screw (male screw, screw portion) (not shown) is inserted into the first screw hole 18a. The left and right ends of the connection portion 18 constitute a rear corner portion 19. An engaged portion 20 constituting a part of the snap - fit portion F described later is formed at this rear corner portion 19 and the above - described front corner portion 16. Since the structures of the respective engaged portions 20 are the same, here, the engaged portion 20 formed at the rear corner portion 19 on the left side X1 will be described in detail.

[0026] Then, to prevent complication, detailed descriptions and reference numerals for the other engaged portions 20 will be simplified or omitted. The engaged portion 20 includes a first stepped portion 21 that is recessed in the front side Y1 (front-rear direction Y), and a second stepped portion 22 that is recessed in the right side X2 (left-right direction X). The rear surface 23, which is the surface facing the rear side Y2 (front-rear direction Y) of the first stepped portion 21, and the left surface 24, which is the surface facing the left side X1 (left-right direction X) of the second stepped portion 22, can abut against the base end portion 64 in the snap fit portion F described later, and constitute a restricting portion 25 that restricts the displacement of the base end portion 64 in the left-right direction X or the front-rear direction Y. The lower end portion of the second stepped portion 22 is bent to the right side X2 to form a substantially right-angled corner portion, and this corner portion constitutes a locking portion 26 that locks the claw portion 68 described later in the snap fit portion F. A locking groove 27 that opens to the left side X1 (outward in the left-right direction X) is continuously formed on the lower side Z1 of the locking portion 26. The locking groove 27 extends downward to the lower end portion of the connecting portion 18. The rear wall surface 27a, which is the end surface facing the rear side Y2 of the locking groove 27, can abut against the base end portion 64 in the snap fit portion F described later, and like the rear surface 23 of the first stepped portion 21 and the left surface 24 of the second stepped portion 22, constitutes the restricting portion 25 of the present invention.

[0027] An opening 28 that opens in the vertical direction Z (predetermined direction) is formed at the upper end portion of the case 10 formed in this way. The opening end surface of the opening 28 includes a flat surface 28a facing the upper side Z2, and an inclined surface 28b continuous with the inner edge portion of the flat surface 28a on the inner side of the case 10. The flat surface 28a is constituted by the upper end surface of the front wall 12, the upper end surface of the side wall 15, and the upper end surface of the rear wall 17. At least a part of the flat surface 28a can abut against the back surface 60 (opposing surface) of the cover 50 described later. The inclined surface 28b extends along the upper edge portions of the front wall inner surface 12a, which is the inner surface of the front wall 12, the side wall inner surface 15a, which is the inner surface of the side wall 15, and the rear wall inner surface 17a, which is the inner surface of the rear wall 17, respectively, and is inclined so as to be located inward as it goes toward the lower side Z1. And an R-shaped portion 28c that connects the inclined surfaces 28b to each other is formed on the opening end surface of the opening 28. The R-shaped portion 28c extends to the inner surface 11a of the bottom plate 11, which is the inner surface of the bottom plate 11, toward the lower side Z1, and constitutes the four corners of the inner surface of the case 10.

[0028] The interior of the case 10 surrounded by the inner surface 11a of the bottom plate, the inner surface 12a of the front wall, the inner surface 15a of the side wall, and the inner surface 17a of the rear wall constitutes a substantially rectangular accommodation space 29 (terminal block body recess). The accommodation space 29 houses two contacts 30 and two switching means 40. If one contact 30 and one switching means 40 are taken as a set, in this embodiment, two sets of contacts 30 and switching means 40 are provided adjacent to the left side X1 and the right side X2. The two sets of contacts 30 and switching means 40 are arranged so as to be rotationally symmetric about the center of the bottom plate 11. Since the contacts 30 and switching means 40 on the left side X1 and the contacts 30 and switching means 40 on the right side X2 have the same configuration, in the following description, the contacts 30 and switching means 40 on the left side X1 will be described in detail, and for the contacts 30 and switching means 40 on the right side X2, detailed description and reference numerals will be omitted or simplified.

[0029] The contact 30 is a conductive member made of a conductive material, and as shown in FIG. 4, includes a pair of fixed contacts 31 fixed in the accommodation space 29 and a movable contact 34 disposed between the pair of fixed contacts 31. The pair of fixed contacts 31 is composed of a first fixed contact 32 and a second fixed contact 33. The first fixed contact 32 is fixed to the inner surface 11a of the bottom plate and faces upward Z2. The second fixed contact 33 faces the first fixed contact 32 while being fixed to a support plate 35 protruding inward from the side wall inner surface 15a side. The movable contact 34 is fixed to the tip of an outer spring 44 described later, and by displacing upward Z2 or downward Z1, it abuts against the first fixed contact 32 or the second fixed contact 33 and can be electrically connected to the first fixed contact 32 or the second fixed contact 33.

[0030] The switching means 40 reversely operates as the operating shaft 70 described later moves, and conducts the movable contact 34 to one or the other of the first fixed contact 32 and the second fixed contact 33. The switching means 40 is, for example, a leaf spring formed by bending a metal plate member, and includes a contact plate 41 fixed to the inner surface 11a of the bottom plate of the case 10. The contact plate 41 has a bent portion 42 curved toward the rear side Y2 by turning back toward the front side Y1 from the fixed position, and a plate-shaped inner spring 43 continuously extending toward the front side Y1 at the center in the left-right direction X of the bent portion 42. Further, the contact plate 41 includes an outer spring 44 formed in a plate shape surrounding the inner spring 43 and continuous with the bent portion 42, and a reversing spring 45 connecting the inner spring 43 and the outer spring 44. An engaging hole 43a penetrating in the vertical direction Z is formed in the inner spring 43, and the operating shaft 70 is engaged with the engaging hole 43a in an inserted state. The movable contact 34 is fixed to the front end portion of the outer spring 44 in an inserted state.

[0031] The reversing spring 45 can be contracted in a direction of closing while bringing closer a first connecting portion 46 which is a connecting portion with the inner spring 43 and a second connecting portion 47 which is a connecting portion with the outer spring 44. Thereby, a reversing spring load is generated in a direction of opening while separating the first connecting portion 46 and the second connecting portion 47. The switching means 40 configured in this way biases the movable contact 34 toward the first fixed contact 32 in the initial state shown in FIG. 4. For this reason, a first conduction state is achieved in which the movable contact 34 abuts on the first fixed contact 32 and conducts.

[0032] Next, the cover 50 will be described. The cover 50 is a member that covers the opening 28 of the case 10 and is formed using, for example, a resin material. As shown in FIG. 2, the cover 50 includes a cover body 51 in the shape of a substantially rectangular plate. A communication hole 52 penetrating in the vertical direction Z is formed on the front side Y1 of the cover body 51. The communication hole 52 communicates with the mounting hole 13 of the front wall 12 in the case 10 described above, and a reset shaft (not shown) is inserted through the communication hole 52 in the same manner. As shown in FIG. 4, an insertion hole 53 penetrating in the vertical direction Z is formed at the center of the cover body 51, and the operating shaft 70 is supported in the insertion hole 53 so as to be able to move forward and backward in the vertical direction Z in a state where the operating shaft 70 is inserted. Note that the operating shaft 70, a seal portion 80 (to be described later) that holds the operating shaft 70, a lever 90 (transmission member) that transmits an external force to the operating shaft 70, and a structure that supports the lever 90 (hereinafter referred to as the structure of the operating shaft 70 etc.) are provided in a pair corresponding to the two sets of contacts 30 and switching means 40 described above, respectively.

[0033] Specifically, as shown in FIG. 2, the structures of the operating shaft 70 etc. are provided in a pair side by side in the left - right direction X. Since the structures of the operating shaft 70 etc. are the same on the left and right, in the following description, the structure of the operating shaft 70 etc. arranged on the left side X1 will be described in detail, and the description and reference numerals of the structure of the operating shaft 70 etc. on the right side X2 will be omitted or simplified. The operating shaft 70 is a shaft member that converts the rotational movement of the lever 90 into a forward and backward movement in the vertical direction Z, and moves forward and backward in the vertical direction Z (axis direction) to act on the switching means 40. The upper end portion of the operating shaft 70 is located outside the case 10 and constitutes a pressed portion 71 that is pressed by the lever 90. The pressed portion 71 is in sliding contact with the V - shaped inner surface of a receiving portion 91 (to be described later) of the lever 90 and is pressed downward Z1.

[0034] On one hand, the lower end of the operating shaft 70 is located within the case 10 and constitutes an engaging end 72 that engages with the engaging hole 43a of the switching means 40. In this way, the operating shaft 70 passes through the cover 50 and extends both inside and outside the case 10. The operating shaft 70 is held by a seal portion 80 that closes the gap between the inner surface of the insertion hole 53 and is connected to the case 10. The seal portion 80 is provided to hermetically seal between the operating shaft 70 and the insertion hole 53 so that fluid does not intrude into the accommodation space 29 from between the operating shaft 70 and the inner surface of the insertion hole 53. The seal portion 80 is formed in a cylindrical shape using, for example, a flexible resin material or the like. The upper end opening edge 81 of the seal portion 80 covers the operating shaft 70 in the circumferential direction around the axis, and the lower end opening edge 82 of the seal portion 80 covers the opening edge of the insertion hole 53.

[0035] As shown in FIG. 4, a standing wall portion 54 rising upward in the upper side Z2 is formed at the rear end portion of the cover main body 51. A second screw hole 55 penetrating in the vertical direction Z is formed at the central portion of the standing wall portion 54. The second screw hole 55 is provided coaxially with the first screw hole 18a formed in the connecting portion 18 of the case 10 described above, and a fixing screw (not shown) described above is inserted in the same manner as the first screw hole 18a. The fixing screw inserted through the first screw hole 18a and the second screw hole 55 is provided to be screwed into a female screw (threaded portion) provided on the top wall portion 115, and by this fixing screw, the cover 50 and the case 10 are clamped and fixed together. Note that the connection between the case 10 and the cover 50 does not necessarily have to be made with a fixing screw. When the fixing screw is omitted, the first screw hole 18a and the second screw hole 55 may be omitted. Also, a female screw may be formed in at least one of the first screw hole 18a or the second screw hole 55, and the cover 50 and the case 10 may be fixed without using the female screw on the top wall portion 115 of the main body frame 111. A pedestal 56 extending in the front side Y1 is formed on the front end face of the standing wall portion 54. The pedestal 56 is formed in a substantially rectangular parallelepiped shape. A support portion 57 for supporting the lever 90 is attached to the pedestal 56. The support portion 57 is formed in a substantially U shape by bending a metal plate member and covers the upper surface and the side surface of the pedestal 56. The support portion 57 is fixed to the pedestal 56 by a screw 58 penetrating through the upper surface.

[0036] On the side of the support portion 57, a rotation shaft 59 extending in the left - right direction X is supported. And, a lever 90 is supported rotatably about the rotation shaft 59. In the present embodiment, "rotation" means rotating forward and backward within a predetermined angle range about the rotation shaft 59. The lever 90 is an operating metal fitting formed in a plate shape from a metal material, extends forward Y1 from the rotation shaft 59, and is provided rotatably on one side a and the other side b about the rotation shaft 59. In the initial state shown in FIG. 4, the lever 90 is biased to the other side b by the biasing means of the switching means 40, and extends while being inclined so as to be located on the upper side Z2 from the rear end portion supported by the rotation shaft 59 toward the front end portion.

[0037] The lever 90 rotates to one side a about the rotation shaft 59 when receiving an external force. Examples of the external force include, for example, a force generated in response to a pressure change of the refrigerant in the above - mentioned refrigeration cycle. Such a force is applied to a sensitive member (not shown) mounted on the pressure switch and transmitted to the lever 90 via the transmission mechanism 118. A receiving portion 91 is formed on the plate surface of the lever 90. The receiving portion 91 is formed by protruding the middle portion in the front - rear direction Y of the plate surface of the lever 90 upward Z2, and has a V - shaped cross - sectional surface opening downward Z1. The pressed portion 71 of the operating shaft 70 described above is supported by the receiving portion 91. As the receiving portion 91 presses the pressed portion 71 with the rotation of the lever 90 receiving an external force, the operating shaft 70 moves forward and backward in the vertical direction Z. That is, the lever 90 moves the operating shaft 70 forward and backward in the vertical direction Z by transmitting an external force.

[0038] Next, the structure on the back side of the cover 50 will be described. As shown in FIG. 4, the back surface 60 of the cover 50 constitutes a facing surface that faces the flat surface 28a of the case 10 in the vertical direction Z, and at least a part of this back surface 60 can abut against the flat surface 28a (opening end surface). A frame portion 61 that protrudes downward toward Z1 is formed at the center of the back surface 60. As shown in FIG. 4, a seal member S is assembled to the outer surface of the frame portion 61 so as to follow along. In the present embodiment, the seal member S is made of an elastic resin material and is formed in a substantially rectangular annular shape with R-shaped corners.

[0039] The seal member S is disposed between the inclined surface 28b (opening end surface) in the opening 28 and the back surface 60 (facing surface) of the cover 50, and seals between the inclined surface 28b and the back surface 60 in a state of being compressed in the vertical direction Z. That is, the seal member S is interposed between the case 10 and the cover 50 to seal the opening 28. According to this, by the above-described seal portion 80 and the installation of the seal member S, for example, the airtightness in the accommodation space 29 is set to have an airtightness of at least several 10 kPa from the accommodation space 29 side. With this configuration, even when the pressure-responsive switch 100 is used in a flammable fluid atmosphere, it is possible to prevent the flammable fluid from entering the accommodation space 29 and reduce the risk of ignition caused by the spark generated by the operation of the microswitch 1. The setting of the airtightness of the accommodation space 29 is not limited to the above, and can be arbitrarily set according to the assumed use environment. For example, when it is possible to prevent intrusion into the accommodation space 29 and allow the intrusion of gaseous fluid, the airtightness of the accommodation space 29 may be set to such an extent that the intrusion of foreign matter can be prevented.

[0040] As shown in FIG. 5, in the central portion of the frame portion 61, a partition plate 61a is integrally formed which rises toward the lower side Z1 and extends in the front-rear direction Y from the inner surface of the rear portion of the frame portion 61 to the inner surface of the front portion of the frame portion 61. The partition plate 61a functions as a partition that divides the accommodation space 29 into one space for accommodating a set of contacts 30 and switching means 40 and another space for accommodating another set of contacts 30 and switching means 40, and also functions as a rib for enhancing the rigidity of the entire cover 50. On the upper surface of the frame portion 61, a cover protrusion 62 (protrusion) protruding toward the lower side Z1 (opening direction) is formed. In the present embodiment, the cover protrusions 62 are arranged near the left front corner portion and the right rear corner portion of the frame portion 61, and include an independent first cover protrusion 62a (first protrusion) and a second cover protrusion 62b (second protrusion), respectively. Note that the arrangement and number of the first cover protrusions 62a and the second cover protrusions 62b are merely examples, and the first cover protrusion 62a or the second cover protrusion 62b may be arranged other than near the left front corner portion and the right rear corner portion of the frame portion 61, or two or more first cover protrusions 62a or second cover protrusions 62b may be arranged on portions other than the frame portion 61.

[0041] Since the structures of the first cover protrusions 62a and the second cover protrusions 62b are the same, in the following description, the first cover protrusion 62a arranged near the right rear corner portion and the second cover protrusion 62b will be described in detail, and the descriptions and reference numerals of the other first cover protrusions 62a and second cover protrusions 62b will be omitted or simplified. As shown in FIG. 5, the first cover protrusion 62a includes a rear outer surface 62a1 facing the rear side Y2 (front-rear direction Y) and extends in the left-right direction X. The second cover protrusion 62b includes a right outer surface 62b1 facing the right side X2 (left-right direction X) and extends in the front-rear direction Y. As shown in FIG. 4, in a state where the cover 50 is attached to the case 10, the rear outer surface 62a1 of the first cover protrusion 62a is in contact with the inner surface 17a of the rear wall of the case 10. On the other hand, the right outer surface 62b1 of the second cover protrusion 62b is in contact with the inner surface 15a of the side wall on the right side X2 of the case 10.

[0042] And, as shown in FIG. 5, an engaging portion 63 is formed on the back surface 60 of the cover 50. The engaging portion 63, together with the engaged portion 20 of the case 10 described above, constitutes a snap fit portion F. Four engaging portions 63 are formed corresponding to the number of the engaged portions 20. However, since the structures of the respective engaging portions 63 are the same, in the following description, the engaging portion 63 formed on the left rear side will be described in detail, and for the other engaging portions 63, the detailed description and reference numerals will be omitted or simplified. The engaging portion 63 includes a base end portion 64 that rises upward in the lower side Z1 from the back surface 60 of the cover 50. The base end portion 64 is formed in an L shape in a sectional view of a cross section orthogonal to the vertical direction Z with a first base end portion 65 and a second base end portion 66 having an elastic portion 67 described later, improving the strength of the engaging portion 63. The first base end portion 65 includes a front inner wall surface 65a facing the front side Y1 (front-rear direction Y) and extends in the vertical direction Z. The front inner wall surface 65a of the first base end portion 65 faces the rear surface 23 (see FIG. 3, restriction portion 25) facing the rear side Y2 of the engaged portion 20 described above with a slight gap in the front-rear direction Y.

[0043] The second base end portion 66 includes a right inner wall surface 66a facing the right side X2 (left-right direction X) and extends in the vertical direction Z. The right inner wall surface 66a of the second base end portion 66 abuts against the left surface 24 (see FIG. 3, restriction portion 25) facing the left side X1 of the engaged portion 20 described above in the left-right direction X. Further, the second base end portion 66 includes a front surface 66b that is an end surface facing the front side Y1 (front-rear direction Y), and the front surface 66b faces the rear wall surface 27a (see FIG. 3, restriction portion 25) of the locking groove 27 described above with a slight gap in the front-rear direction Y. An elastic portion 67 extending downward in the lower side Z1 is formed at the lower end portion of the second base end portion 66. The elastic portion 67 is provided so as to be elastically deformable in the left-right direction X starting from the base end portion 64 side. A claw portion 68 protruding inward in the right side X2 (left-right direction X) is formed at the lower end portion of the elastic portion 67. The claw portion 68 is locked to the locking portion 26 of the engaged portion 20 in a state where the cover 50 is attached to the case 10 and is located in the locking groove 27.

[0044] With this configuration, the case 10 is held by the second base end portion 66 that abuts against the left surface 24 (restricted portion 25) of the engaged portion 20, the elastic portion 67 that extends downward in the Z1 direction from the second base end portion 66, and the claw portion 68 that is locked to the locking portion 26 of the engaged portion 20. As a result, displacement of the engaging portion 63 in the vertical direction Z and the horizontal direction X is restricted. Further, according to this configuration, if the engaging portion 63 attempts to displace to the front side Y1, for example, the front inner wall surface 65a of the first base end portion 65 that faces the rear surface 23 of the engaged portion 20 with a slight gap therebetween can abut against the rear surface 23, so that displacement of the engaging portion 63 to the front side Y1 is restricted by this abutment.

[0045] Also, similarly, if the engaging portion 63 attempts to displace to the front side Y1, for example, the front surface 66b of the second base end portion 66 that faces the rear wall surface 27a of the locking groove 27 with a slight gap therebetween can abut against the rear wall surface 27a, so that displacement of the engaging portion 63 to the front side Y1 is also restricted by this abutment. In this way, displacement of the engaging portion 63 in the front-rear direction Y is also restricted. Note that reference numeral 69 in the figure indicates a through hole. The through hole 69 is a hole for removing the mold for forming the claw portion 68 of the engaging portion 63 when resin molding the cover 50, and is formed to penetrate in the vertical direction Z in accordance with the number of claw portions 68.

[0046] Next, the assembly of the microswitch 1 will be described. First, as shown in FIG. 3, the contact 30 and the switching means 40 are housed inside the case 10 and fixed in the housing space 29. Next, as shown in FIG. 5, the cover 50 is arranged with the back surface 60 facing the upper side of the paper surface. Next, a seal member S is prepared. In this embodiment, since the assembly on the case 10 side is completed by housing the contact 30 and the switching means 40 in the housing space 29, it is not necessary to install other structures such as the lever 90, the pedestal 56 for supporting the lever 90, the support portion 57, and the rotation shaft 59 on the case 10. Therefore, the shape of the opening 28 to be sealed by the seal member S is a simple shape such as a substantially rectangular shape in this embodiment. For this reason, the shape of the seal member S can be a simple shape such as a substantially rectangular ring shape, and the molding and attachment of the seal member S are facilitated.

[0047] Next, as shown in FIG. 4, the operating shaft 70 is inserted through the insertion hole 53 of the cover 50, held by the seal portion 80, and the operating shaft 70 is attached to the cover 50 in this state. Then, the support portion 57 in a state where the lever 90 is supported by the rotation shaft 59 is fixed to the pedestal 56 by the screw 58. As a result, the cover 50, the operating shaft 70, the seal portion 80, and the lever 90 are integrated into one unit. Next, the seal member S is assembled to the frame portion 61 of the cover 50. Next, the cover 50 is attached to the case 10. At this time, the positions of the case 10 and the cover 50 are adjusted as follows. First, the flat surface 28a of the case 10 and the back surface 60 of the cover 50 are opposed to each other in the vertical direction Z, and the inclined surface 28b of the case 10 and the frame portion 61 (the frame portion 61 in a state where the seal member S is assembled) of the cover 50 are opposed to each other in the vertical direction Z. Also, each engaged portion 20 in the case 10 and each engaging portion 63 in the cover 50 are opposed to each other in the vertical direction Z. Further, the mounting hole 13 of the case and the communication hole 52 of the cover 50 are opposed to each other in the vertical direction Z. Also, the first screw hole 18a of the case 10 and the second screw hole 55 of the cover 50 are opposed to each other in the vertical direction Z.

[0048] After adjusting the positions of the case 10 and the cover 50 in this way, the cover 50 is brought closer to the case 10. At this time, for example, at the cover protrusion 62 located at the right rear corner portion described above, the rear outer surface 62a1 of the first cover protrusion 62a abuts against the inner surface 17a of the rear wall of the case 10. At this time, the first cover protrusion 62a is slightly bent inward and closely adheres to the inner surface 17a of the rear wall in a lightly press-fitted state. Similarly, the right outer surface 62b1 of the second cover protrusion 62b in the cover 50 abuts against the inner surface 15a of the side wall on the right side X2 of the case 10. At this time, the second cover protrusion 62b is slightly bent inward and closely adheres to the inner surface 15a of the side wall in a lightly press-fitted state. Incidentally, at this time, although not shown in the figure, the outer surface of the first cover protrusion 62a located at the left front corner portion of the frame portion 61 where the detailed description is omitted is in close contact with the inner surface 12a of the front wall in a lightly press-fitted state. Also, the outer surface of the second cover protrusion 62b located at the left front corner portion of the frame portion 61 is in close contact with the inner surface 15a of the side wall on the left side X1 in a lightly press-fitted state.

[0049] Also, at this time, the seal member S abuts against the back surface 60 of the cover 50 and the inclined surface 28b of the case 10, and is compressed from above and below by the inclined surface 28b and the back surface 60 to seal between the inclined surface 28b and the back surface 60. And at this time, as described above and as shown in FIG. 4, since at least a part of the back surface 60 of the cover 50 and the flat surface 28a of the case 10 can abut against each other, these back surface 60 and flat surface 28a act as the contact portion C. In this way, the flat surface 28a and the back surface 60 (opposing surface) are provided with the contact portion C that can abut against each other. Further, when the cover 50 is brought closer to the case 10, outside the case 10, the claw portion 68 of the engaging portion 63 is pressed against the second step portion 22 in the engaged portion 20 of the case 10. As a result, the elastic portion 67 is elastically deformed outward in the left-right direction X. And in the state where the back surface 60 of the cover 50 abuts against the flat surface 28a of the case 10, the claw portion 68 fits into the locking groove 27 at the position where it has overcome the locking portion 26 toward the lower side Z1, and the elastic portion 67 abuts against the locking portion 26 by the force to return to the state before elastic deformation, and is locked. And finally, a fixing screw (male screw, screw portion) (not shown) is inserted through the first screw hole 18a and the second screw hole 55, and screwed into the female screw (screw portion) of the top wall portion 115 of the main body frame 111 and tightened together to fix the case 10 and the cover 50. Thereby, the assembly of the microswitch 1 is completed.

[0050] Next, the operation of the microswitch 1 will be described. Here, as an example of the operation, a case where the microswitch 1 is mounted on a pressure responsive switch 100 that detects the pressure of a refrigerant in a refrigeration cycle system and is used to detect an abnormal high pressure will be described. First, in the initial state where the lever 90 is not rotated, the movable contact 34 is in conduction with the first fixed contact 32 as shown in FIG. 4, and is in the first conduction state described above. From this state, when the pressure (i.e., external force) of the refrigerant introduced into the element 116 via the joint pipe 117 shown in FIG. 1 rapidly rises, a sensitive member such as a bellows or a diaphragm changes in the front-rear direction Y according to the pressure change. And this change is transmitted to the lever 90 as an operating force via the transmission mechanism 118.

[0051] The lever 90 that has received the operating force (external force) rotates to one side a around the rotation axis 59. The rotational movement of the lever 90 is transmitted to the operating shaft 70 via the receiving portion 91 and the pressed portion 71, and is converted into a movement of the operating shaft 70 toward the lower side Z1. As a result, the operating shaft 70 moves to the lower side Z1. Along with the movement of the operating shaft 70, the inner spring 43 deforms so that the front end portion of the inner spring 43 is displaced to the lower side Z1. Along with this, the reversing spring 45 deforms, and the rear end portion of the outer spring 44 deforms so as to bend toward the lower side Z1. Then, due to the balance of the forces of the inner spring 43, the outer spring 44, and the reversing spring 45 trying to return to the state before deformation being disrupted, a reversing operation occurs in which the movable contact 34 jumps upward toward the upper side Z2, and the movable contact 34 switches to a second conduction state in which it conducts with the second fixed contact 33. According to this configuration, for example, by mounting the microswitch 1 on the pressure-responsive switch 100, a high-pressure cut-off switch can be configured that switches the conduction destination of the movable contact 34 from the first fixed contact 32 to the second fixed contact 33 when an abnormal high pressure occurs.

[0052] Here, in the pressure-responsive switch 100 equipped with the microswitch 1, due to the assembly error between the case 10 and the cover 50, the position of the lever 90 may deviate from the designed position. Also, depending on the usage environment or the like, for example, due to vibration, impact, or heat load, etc., the positions of the case 10 and the cover 50 may shift relative to each other, causing the position of the lever 90 to deviate from the designed position. In this case, the transmission of the external force by the lever 90 may vary among products or shift during use, making it impossible to perform accurately, and the switching operation of the contact point 30 becomes unstable. In particular, the pressure-responsive switch 100 is not a device that can switch the conduction state of the contact point 30 by, for example, forcing an external force to be transmitted to the operating shaft 70 by pushing in the lever 90 with a finger or the like of a user or the like. Specifically, the pressure-responsive switch 100 is a device configured such that the lever 90 and the operating shaft 70 operate in response to a predetermined pressure (external force). For this reason, in the pressure-responsive switch 100, the deviation of the position of the lever 90 is likely to be a problem because it means that accurate pressure detection cannot be performed. And, as described above, in the configuration where the seal member S is interposed between the case 10 and the cover 50, for example, as the lever 90 rotates, the cover 50 sinks toward the opening 28 side while elastically deforming the seal member S, etc., and the elastic force of the seal member S makes it easier for the positions of the case 10 and the cover 50 to shift relative to each other, making the above problem more likely to occur.

[0053] However, in the present embodiment, as described above, since the contact portion C capable of contacting each other is provided on the flat surface 28a of the case 10 and the back surface 60 of the cover 50, at least a part of the contact portion C comes into contact with each other, and displacement of the cover 50 toward the opening 28 side can be easily prevented. That is, the contact portion C is provided on the case 10 and the cover 50 and functions as a displacement restricting means for suppressing displacement from each other. Further, the rear outer surface 62a1 of the first cover protrusion 62a contacts the rear wall inner surface 17a (or the front wall inner surface 12a), so that displacement in the rear side Y2 (or the front side Y1) is restricted. Thereby, displacement of the positions of the case 10 and the cover 50 in the front-rear direction Y (the first direction) from each other is restricted. That is, the rear wall inner surface 17a (or the front wall inner surface 12a) functions as the first restricting portion of the present invention, and the first cover protrusion 62a and the first restricting portion function as displacement restricting means. Further, the right outer surface 62b1 of the second cover protrusion 62b provided independently of the first cover protrusion 62a contacts the side wall inner surface 15a on the right side X2 (or the side wall inner surface 15a on the left side X1) provided independently of the rear wall inner surface 17a (or the front wall inner surface 12a), so that displacement in the left side X1 (or the right side X2) is restricted. Thereby, displacement of the positions of the case 10 and the cover 50 in the left-right direction X (the second direction) from each other is restricted.

[0054] That is, the inner surface 15a of the side wall on the right side X2 (or the inner surface 15a of the side wall on the left side X1) functions as the second restricting portion of the present invention, and the second cover protrusion 62b and the second restricting portion function as displacement restricting means. Note that since the first cover protrusion 62a, the second cover protrusion 62b, the first restricting portion, and the second restricting portion are provided independently of each other, the degree of freedom in arranging the displacement restricting means is improved. For this reason, as shown in FIG. 4, it becomes easy to arrange the first cover protrusion 62a and the second cover protrusion 62b at positions avoiding the R-shaped portion 28c. For this reason, it is not necessary to change the shape of the case 10, the cover 50, etc. according to the arrangement of the displacement restricting means, and the influence of the displacement restricting means on the shapes of the case 10 and the cover 50 is small. Note that the arrangement and number of the first cover protrusion 62a and the second cover protrusion 62b can be arbitrarily selected. However, when the second cover protrusion 62b is omitted, the case 10 and the cover 50 are likely to be displaced in the left-right direction X, which is the deformation direction of the elastic portion 67 in the snap fit portion F. For this reason, since the elastic portion 67 is more likely to be deformed, in order to restrict the displacement of the cover 50 only by the snap fit portion F, it becomes necessary to make the elastic portion 67 higher in strength (or higher in rigidity). When the snap fit portion F is made higher in strength (or higher in rigidity) in this way, it becomes difficult to assemble the cover 50 to the case 10. Therefore, it is desirable to provide the second cover protrusion 62b.

[0055] Further, in the snap fit portion F, when the claw portion 68 of the engaging portion 63 is locked to the locking portion 26, the displacement of the claw portion 68 upward in the Z2 direction is restricted by the locking portion 26. Thereby, the displacement of the cover 50 upward in the Z2 direction with respect to the case 10 is restricted. That is, the snap fit portion F composed of the engaging portion 63 and the engaged portion 20 functions as displacement restricting means for restricting the displacement of the positions of the case 10 and the cover 50 from shifting in the vertical direction Z with respect to each other.

[0056] Also, at this time, the right inner wall surface 66a of the second base end portion 66 of the engaging portion 63 abuts against the restricting portion 25 of the engaged portion 20 (for example, the left surface 24 facing the left side X1 of the engaged portion 20 described above, see FIG. 3) in the left-right direction X, and the displacement in the right side X2 (left-right direction X) is restricted. Further, if the engaging portion 63 should try to displace in the front side Y1 (front-rear direction Y), the front inner wall surface 65a of the first base end portion 65 can abut against the restricting portion 25 of the engaged portion 20 (for example, the rear surface 23 facing the rear side Y2 of the engaged portion 20, see FIG. 3), and thus the displacement of the engaging portion 63 in the front side Y1 (front-rear direction Y) is restricted by this abutment. Similarly, even if the engaging portion 63 should try to displace in the front side Y1 (front-rear direction Y), the front surface 66b of the second base end portion 66 of the engaging portion 63 can abut against the restricting portion 25 of the engaged portion 20 (for example, the rear wall surface 27a of the locking groove 27 described above, see FIG. 3), and thus the displacement of the engaging portion 63 in the front side Y1 (front-rear direction Y) is also restricted by this abutment.

[0057] As a result, the positions of the case 10 and the cover 50 are restricted from shifting in the left-right direction X or the front-rear direction Y. Therefore, the base end portion 64 of the engaging portion 63 and the restricting portion 25 of the engaged portion 20 function as displacement restricting means for restricting the positions of the case 10 and the cover 50 from shifting in the intersecting direction (left-right direction X or front-rear direction Y). Note that by providing the base end portion 64 in the snap fit portion F, the dimension of the elastic portion 67 in the up-down direction Z can be relatively shortened, which also contributes to improving the strength of the elastic portion 67. Further, since the base end portion 64 is formed in an L shape in a sectional view of a cross section orthogonal to the up-down direction Z by the first base end portion 65 and the second base end portion 66, it is particularly difficult to deform in the left-right direction X or the front-rear direction Y, and can contribute to improving the strength of the entire snap fit portion F.

[0058] According to the above configuration, for example, the abutment between the rear outer surface 62a1 of the first cover protrusion 62a (first protrusion) and the rear wall inner surface 17a of the case 10 (first restricting portion), the abutment between the front inner wall surface 65a of the first base end portion 65 and the rear surface 23 facing the rear side Y2 of the engaged portion 20, or the abutment between the front surface 66b of the second base end portion 66 and the rear wall surface 27a of the locking groove 27 can all regulate the displacement of the positions of the case 10 and the cover 50 in the front-rear direction Y relative to each other. However, this is merely an example.

[0059] For example, at least one of the following combinations may constitute displacement restricting means for restricting displacement in the front-rear direction Y: the rear outer surface 62a1 of the first cover protrusion 62a (first protrusion) and the rear wall inner surface 17a of the case 10 (first restricting portion), the front inner wall surface 65a of the first base end portion 65 and the rear surface 23 facing the rear side Y2 of the engaged portion 20, and the front surface 66b of the second base end portion 66 and the rear wall surface 27a of the locking groove 27. In this case, it is preferable to use, for example, the rear outer surface 62a1 of the first cover protrusion 62a (first protrusion) and the rear wall inner surface 17a of the case 10 (first restricting portion) as the displacement restricting means for restricting displacement in the front-rear direction Y.

[0060] Then, by screwing a fixing screw (male screw, screw portion), not shown, inserted into the first screw hole 18a and the second screw hole 55, and a female screw (screw portion) provided on the top wall portion 115 of the main body frame 111, the case 10 and the cover 50 are fixed, thereby restricting the displacement of the positions of the case 10 and the cover 50 relative to each other in the vertical direction Z, the left-right direction X, and the front-rear direction Y. Therefore, the female screw formed in the first screw hole 18a and the second screw hole 55 and the fixing screw, not shown, function as displacement restricting means. Thus, in the present embodiment, various displacement restricting means, such as the contact portion C, the inner surfaces of the cover protrusion 62 and the case 10, the locking portion 26 and the claw portion 68 of the snap fit portion F, the restricting portion 25 and the base end portion 64 of the snap fit portion F, or the female screw and the fixing screw (screw portion), prevent the positions of the case 10 and the cover 50 from shifting relative to each other.

[0061] According to the above-described embodiments, by providing the lever 90 (transmission member) on the cover 50, the cover 50, the operating shaft 70, and the lever 90 can be integrated. As a result, it is not necessary to provide in the case 10 a portion such as a side wall that intersects the cover 50 and extends inside and outside the case 10, which makes it difficult to set the sealing location of the seal member S. For this reason, for example, the opening 28 can be sealed by preparing a seal member S along the inclined surface 28b (opening end surface) of the case 10, and the sealing performance can be improved. Therefore, it is possible to provide the microswitch 1 capable of improving the sealing performance.

[0062] Also, according to this configuration, since it is not necessary to provide in the case 10 a portion such as a side wall that intersects the cover 50 and extends inside and outside the case 10 as described above, the shape of the opening 28 of the case 10 can be set to a relatively simple shape such as a quadrangle or a circle. For this reason, the shape of the seal member S can also be a simple shape, and the molding and attachment of the seal member S can be facilitated. Thereby, it is possible to provide the microswitch 1 capable of easily improving the sealing performance at low cost.

[0063] Also, according to this embodiment, since various displacement restricting means are provided on the case 10 and the cover 50, it is possible to suppress the positions of the case 10 and the cover 50 from shifting relative to each other. For this reason, the position of the lever 90 is suppressed from shifting, and the transmission of an external force can be accurately performed. Therefore, the operating stability of the microswitch 1 can be further improved.

[0064] Also, according to this embodiment, by providing the contact portion C as the displacement restricting means, even if the seal member S is arranged over the entire circumference of the opening 28 and interposed between the case 10 and the cover 50, the displacement of the cover 50 toward the opening 28 side is prevented by at least a part of the contact portion C coming into contact with each other. Therefore, the position of the lever 90 is suppressed from shifting, and the transmission of an external force by the lever 90 can be accurately performed.

[0065] Further, according to the present embodiment, by configuring the displacement restricting means with the restricting portion (the inner surface of the case 10) provided on the case 10 and the cover protrusion 62 (protrusion) provided on the cover 50, it is possible to prevent the positions of the cover 50 and the case 10 from shifting in the left-right direction X or the front-rear direction Y (crossing direction) relative to each other. For this reason, the displacement of the lever 90 is suppressed, and the operating stability of the microswitch 1 can be improved. In the present embodiment, the restricting portion is the inner surface of the case 10, but it is not limited thereto, and the restricting portion may be a recess or a hole into which the cover protrusion 62 fits. When the restricting portion is a recess or a hole, it is useful in that the displacement of the cover protrusion 62 in the left-right direction X or the front-rear direction Y can be more restricted by covering the entire outer surface of the cover protrusion 62 with the inner surface of the recess or the hole. On the other hand, when the inner surface of the case 10 is the restricting portion, it is useful in that it is not necessary to form a special structure such as a recess or a hole, and the structure of the case 10 can be simplified.

[0066] Further, according to the present embodiment, the first restricting portion (the inner surface 12a of the front wall or the inner surface 17a of the rear wall) and the second restricting portion (the inner surface 15a of the side wall on the left side X1 or the inner surface 15a of the side wall on the right side X2) provided on the case 10, and the first cover protrusion 62a (first protrusion) and the second cover protrusion 62b (second protrusion) provided on the cover 50 are used as the displacement restricting means. For this reason, by restricting the displacement of the first cover protrusion 62a in the front-rear direction Y by the first restricting portion, it is possible to restrict the positions of the case 10 and the cover 50 from shifting in the front-rear direction Y relative to each other. Also, by restricting the displacement of the second cover protrusion 62b in the left-right direction X by the second restricting portion, it is possible to restrict the positions of the case 10 and the cover 50 from shifting in the left-right direction X relative to each other. Further, by providing the first cover protrusion 62a, the second cover protrusion 62b, the first restricting portion, and the second restricting portion independently of each other, the degree of freedom in arranging the displacement restricting means is improved, and thus the influence of the displacement restricting means on the shapes of the case 10 and the cover 50 can be reduced.

[0067] In this embodiment, for example, a configuration is exemplified in which the inner surface 17a of the rear wall as the first restricting portion and the outer rear surface 62a1 of the first cover protrusion 62a are in direct contact with each other. However, the present invention is not limited to this, and the restricting portion and the cover protrusion 62 may be indirectly in contact with each other, and the manner of contact may be point contact or line contact.

[0068] Further, in this embodiment, the displacement restricting means is constituted by the snap fit portion F including the engaged portion 20 provided on the case 10 and the engaging portion 63 provided on the cover 50, so that the positions of the case 10 and the cover 50 can be restricted from shifting in the vertical direction Z with respect to each other. Therefore, the operating stability of the microswitch 1 can be improved.

[0069] Further, in this embodiment, the front inner wall surface 65a of the first base end portion 65 of the engaging portion 63 faces the restricted portion 25 (for example, the above-described rear surface 23 shown in FIG. 3) of the engaged portion 20 with a slight gap in the front-rear direction Y. Even if the engaging portion 63 tries to displace in the front side Y1 (front-rear direction Y), since the front inner wall surface 65a can contact the restricted portion 25, the displacement of the engaging portion 63 in the front side Y1 (front-rear direction Y) is restricted. Further, in this embodiment, the front surface 66b of the second base end portion 66 of the engaging portion 63 faces the restricted portion 25 (for example, the above-described rear wall surface 27a shown in FIG. 3) of the engaged portion 20 with a slight gap in the front-rear direction Y. Even if the engaging portion 63 tries to displace in the front side Y1 (front-rear direction Y), since the front surface 66b can contact the rear wall surface 27a, the displacement of the engaging portion 63 in the front side Y1 (front-rear direction Y) is restricted. Further, the right inner wall surface 66a of the second base end portion 66 of the engaging portion 63 contacts the restricted portion 25 (for example, the above-described left surface 24 shown in FIG. 3) of the engaged portion 20, so that the displacement of the engaging portion 63 in the right side X2 (left-right direction X) is restricted. That is, since the displacement of the base end portion 64 of the engaging portion 63 in the left-right direction X or the front-rear direction Y is restricted by the restricted portion 25 of the engaged portion 20, the positions of the case 10 and the cover 50 can also be restricted from shifting in the left-right direction X or the front-rear direction Y. Therefore, the operating stability of the microswitch 1 can be further improved.

[0070] Further, according to the present embodiment, a fixing screw (male screw, threaded portion) inserted into the first screw hole 18a and the second screw hole 55 and a female screw (threaded portion) formed in the top wall portion 115 of the housing 110 constitute displacement restricting means, and the case 10 and the cover 50 can be fixed. Therefore, the positions of the case 10 and the cover 50 can be restricted from shifting relative to each other in the vertical direction Z, the left - right direction X, and the front - rear direction Y.

[0071] Also, according to the present embodiment, a pressure - responsive switch 100 can be provided by using a micro - switch 1 capable of improving the sealing performance.

[0072] Next, a first modification example of the micro - switch 1 will be described. FIG. 6 is a perspective view of a micro - switch 200 in the first modification example. In the first modification example, it is different from the above - described embodiment in that a second fixing screw 201 for fixing the cover 50 and the case 10 is provided in the front - side Y1 portion of the cover 50. The second fixing screw 201 is provided so as to penetrate the cover 50, constitutes a threaded portion for fixing the case 10 and the cover 50, and functions as displacement restricting means. In the micro - switch 1 of the first modification example shown in FIG. 6, although a snap - fit portion F is provided, since the second fixing screw 201 can constitute displacement restricting means, the snap - fit portion F may have a function only for temporarily fixing the cover 50 and may be omitted. According to such a configuration, the displacement restricting means can be easily constituted by the second fixing screw 201.

[0073] Next, a second modification of the microswitch 1 will be described. FIG. 7 is an enlarged cross-sectional view of the microswitch 300 cut along the vertical direction Z in the second modification. In the second modification, the structure around the opening 28 is different from that in the above-described embodiment. A protruding portion 301 protruding upward in the Z2 direction is formed on the opening end surface of the case 10. The upper end surface 302 of the protruding portion 301 can abut against the back surface 60 of the case 10, and constitutes the abutting portion C of the second modification. Then, due to the formation of the protruding portion 301, a stepped portion 303 recessed downward in the Z1 direction is formed on the opening end surface, and a seal member S is installed in this stepped portion 303. On the other hand, on the outer edge portion of the cover 50, a protruding edge portion 304 that engages with the stepped portion 303 is formed to protrude downward in the Z1 direction. An inclined portion 305 with a chamfered corner is formed on the inner edge of the protruding edge portion 304, and the seal member S is compressed by the inclined portion 305 and the surface of the stepped portion 303 of the case 10 facing the upper Z2 direction, and the space between the case 10 and the cover 50 is sealed. According to such a configuration, the cover 50 can be attached to the case 10 with the seal member S assembled on the case 10 side. Therefore, when moving the cover 50, it is not necessary to consider the displacement of the seal member S, and the assembly of the microswitch 1 can be facilitated.

[0074] Note that the embodiments described above merely show typical forms of the present invention, and the present invention is not limited thereto. That is, various modifications can be made and implemented without departing from the gist of the present invention. As long as the configuration of the microswitch 1 of the present invention is provided by such modifications, it is of course included in the scope of the present invention. For example, in the present embodiment, a restricting portion (the inner surface of the case 10) is provided on the case 10 side, and a cover protrusion 62 (protrusion) is provided on the cover 50 side. However, conversely, a protrusion may be provided on the case 10 side and a restricting portion may be provided on the cover 50 side. That is, the displacement restricting means can be configured to include a protrusion protruding in the vertical direction Z from one of the case 10 and the cover 50, and a restricting portion provided on the other of the case 10 and the cover 50.

[0075] In addition, in the present embodiment, the engaged portion 20 that constitutes the snap - fit portion F is provided on the case 10 side, and the engaging portion 63 is provided on the cover 50 side. However, conversely, the engaging portion 63 may be provided on the case 10 side and the engaged portion 20 may be provided on the cover 50 side. That is, the displacement restricting means can be constituted by the snap - fit portion F including the engaging portion 63 disposed on one of the case 10 and the cover 50 and the engaged portion 20 disposed on the other of the case 10 and the cover 50.

[0076] Also, according to the above - described embodiment, the displacement restricting means is constituted using various structures such as the contact portion C, the cover protrusion 62 and the inner surface of the case 10, the locking portion 26 and the claw portion 68 of the snap - fit portion F, the restricted portion 25 and the base end portion 64 of the snap - fit portion F, or the female screw and the fixing screw (threaded portion). However, it is not necessary to use all of the various displacement restricting means. The displacement restricting means may be configured by selecting one from the above - described various displacement restricting means, or may be configured by arbitrarily combining a plurality of the displacement restricting means among the various displacement restricting means.

[0077] Also, although the micro - switch 1 has been described as being used when detecting an abnormal high pressure, conversely, the micro - switch 1 can also be used when detecting an abnormal low pressure. Also, the lever 90 was inclined so as to be located on the upper side Z2 from the rear end portion supported by the rotation shaft 59 toward the front end portion in the initial state. However, conversely, taking the state after rotation in the present embodiment as the initial state of the lever 90, taking the other side b in the present embodiment as the one side a, and adjusting the operating shaft 70, the operating direction of the switching means 40, etc. accordingly, the micro - switch 1 may be constructed.

[0078] In addition to the pressure switch, the microswitch 1 can be mounted on various switches that cause the lever 90 to rotate when receiving some external force. For example, in the pressure-responsive switch 100 of the present embodiment, although the use as a pressure switch has been mainly described, the pressure-responsive switch 100 can also be used as a temperature switch. That is, in the present embodiment, the fluid to be detected (here, the refrigerant circulating in the refrigeration cycle) is introduced through the joint pipe 117, and the pressure change is detected by directly applying the pressure of the fluid to be detected to the sensitive member such as a bellows or a diaphragm. Although the use as a pressure switch has been described as an example, the use of the pressure-responsive switch 100 is not limited to this.

[0079] That is, in the pressure-responsive switch 100 of the present embodiment, a temperature sensing cylinder is connected to the element 116 via a capillary, and a temperature switch can be configured by filling the closed space formed by the sensitive member, the capillary, and the temperature sensing cylinder with the refrigerant. Thus, in the temperature switch using the pressure-responsive switch 100 of the present embodiment, the sensitive member deforms or displaces in the front-rear direction X according to the pressure inside the closed space that changes due to the temperature change detected by the temperature sensing cylinder, and the conduction state of the contact 30 is changed by transmitting the force at this time to the lever 90. Further, in the present embodiment, the microswitch 1 is provided with a pair of levers 90, corresponding operating shafts 70, contacts 30, switching means 40, etc., and constitutes a so-called dual-type microswitch 1. However, the present invention is not limited to the dual-type microswitch 1, and can be applied to various microswitches.

Explanation of Reference Numerals

[0080] S Seal member Z Vertical direction (predetermined direction) 1 Microswitch 10 Case 28 Opening 30 Contact 40 Switching means 50 Cover 70 Operating shaft 90 Lever (transmission member)

Claims

1. A microswitch comprising: a case having an opening that opens in a predetermined direction; a plurality of contacts housed in the case; switching means for switching the conduction state of the contacts; a cover that covers the opening; an operating shaft provided on the cover and extending through the cover to the inside and outside of the case; and a seal member interposed between the case and the cover and capable of sealing the opening. The microswitch is characterized in that a transmission member for advancing and retracting the operating shaft in the axial direction by transmitting an external force is provided on the cover.

2. The microswitch according to claim 1, wherein displacement restricting means for suppressing displacement of the case and the cover relative to each other is provided.

3. The seal member is disposed between an opening end face at the opening and a facing surface on the cover facing the opening end face. The microswitch according to claim 2, wherein the displacement restricting means is constituted by abutting portions provided on the opening end face and the facing surface and capable of abutting against each other.

4. The displacement restricting means includes a protrusion protruding from one of the case and the cover in the opening direction of the opening, and a restricting portion provided on the other of the case and the cover. The restricting portion is provided facing a crossing direction that intersects the opening direction. The microswitch according to claim 2, wherein displacement of the protrusion in the crossing direction is restricted by the restricting portion.

5. The protrusion is provided on the cover. The microswitch according to claim 4, wherein the restricting portion is constituted by an inner surface of the case.

6. The protrusion includes independent first and second protrusions. The microswitch according to claim 4, wherein the restricting portion includes a first restricting portion that restricts displacement of the first protrusion in a first direction among the crossing directions, and a second restricting portion that is provided independently of the first restricting portion and restricts displacement of the second protrusion in a second direction that intersects the first direction among the crossing directions.

7. The displacement restricting means is a snap fit portion including an engaging portion disposed on one of the case and the cover and an engaged portion disposed on the other of the case and the cover. The microswitch according to claim 2, characterized in that, in a state where the engaging portion and the engaged portion are engaged, displacement in the opening direction of the opening portion in the case and the cover is restricted.

8. The engaging portion includes a base end portion, an elastic portion that extends from the base end portion in the opening direction and elastically deforms in an intersecting direction intersecting the opening direction, and a claw portion that protrudes from the elastic portion in the intersecting direction. The microswitch according to claim 7, characterized in that the engaged portion includes a restricting portion that restricts displacement of the base end portion in the intersecting direction, and a locking portion that locks the claw portion.

9. The microswitch according to claim 2, characterized in that the displacement restricting means is constituted by a screw portion that fixes the case and the cover.

10. A pressure-responsive switch including the microswitch according to any one of claims 1 to 9.

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