Pressure Switch

Abstract

To provide a pressure switch in which falling of an operation plate is prevented even when excessive pressure is applied to a pressure responsive portion, thereby enabling improvement of the pressure resistance of the pressure responsive portion, and enabling suppression of the damage to the pressure responsive portion, thereby materializing the pressure switch which can prevent leakage of a pressure medium.SOLUTION: A pressure switch 1 comprises: a restriction member (a shaft 7) provided on the side opposite to a bellows 3 in a horizontal side portion 4b of an operation plate 4 in a main body 2; and a stopper (a pressure rise side stopper 2b) for restricting the rotational movement of the operating plate 4. The abutment of the horizontal side portion 4b against the restriction member restricts the movement of the operation plate 4 even when excessive pressure is added to the bellows 3.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pressure switch. [Background technology]

[0002] Conventionally, a pressure switch has been known which includes a bellows as a pressure-responsive part within a main body, an L-shaped operating plate which rotates around a fulcrum provided on the main body as a result of the expansion and contraction of the bellows, a spring connected to the vertical side of the operating plate and opposed to the movement of the operating plate, an operating shaft which responds to the movement of the operating plate, and a movable contact plate which controls a microswitch through the movement of the operating shaft (see, for example, Patent Documents 1 and 2).

[0003] In such a pressure switch, one end of the operating shaft is engaged with a vertical side portion of the operating plate, and the other end is engaged with a movable contact plate constituting a microswitch. The microswitch also has, for example, two fixed contacts and a movable contact disposed between them. In the microswitch, a movable contact for the fixed contacts is provided at a free end of the movable contact plate. The movable contact plate has a quick reversal mechanism including a deformation spring.

[0004] In such a conventional pressure switch, when the pressure applied to the bellows increases or decreases, the operating plate rotates around the fulcrum, and the movable contact plate moves via the operating shaft which moves in response to the movement of the operating plate. As a result, the movable contact plate selectively connects the movable contact between one or two fixed contacts, and the microswitch is reversed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 50-9571 [Patent Document 2] Japanese Utility Model Application Publication No. 61-193647 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in the conventional pressure switches described in Patent Documents 1 and 2, a pressure-increasing stopper and a pressure-decreasing stopper (Patent Document 1 only has the latter) that regulate the rotational movement of the actuating plate are provided on the main body at a predetermined interval in the vertical direction near the end of the horizontal side of the actuating plate. When excessive pressure is applied to the bellows, the actuating plate is held by a fulcrum provided on the main body and the pressure-increasing stopper provided on the upper side inside the main body, thereby preventing the bellows from stretching.

[0007] However, in such a conventional pressure switch, if the pressure applied to the bellows increases further, the bellows may expand while tilting, causing the operating plate of the main body to tilt. As a result, the operating plate, which is no longer supported by the main body, is pushed up by the lower bellows with the end of the horizontal side tilted downward, and there is a risk that the end of the horizontal side will come off the pressure-down side stopper and fall toward the bottom plate. In this case, the falling off of the operating plate may not only damage the bellows, but also cause leakage of the pressure medium such as refrigerant.

[0008] The object of the present invention is to provide a pressure switch that can prevent the operating plate from falling off and improve pressure resistance even when excessive pressure is applied to the pressure-responsive part, thereby suppressing damage to the pressure-responsive part and preventing leakage of the pressure medium. [Means for solving the problem]

[0009] The pressure switch of the present invention is a pressure switch having a pressure responsive part within a main body, an operating plate that abuts against the pressure responsive part and rotates around a fulcrum provided on the main body by the expansion and contraction of the pressure responsive part, a spring that counters the movement of the operating plate, an operating shaft that responds to the movement of the operating plate, and a movable contact plate that moves a movable contact toward and away from a fixed contact by the movement of the operating shaft, wherein the operating plate has a first edge portion with which the pressure responsive part abuts, and a second edge portion that continues to one end side of the first edge portion via a bent portion, and wherein the main body is provided with a regulating member extending in the same axis direction as the fulcrum at a position near the first edge portion of the operating plate on the side opposite the pressure responsive part, and a stopper that abuts against the other end side of the first edge portion to regulate the rotational movement of the operating plate, and wherein when excessive pressure is applied to the pressure responsive part, the movement of the operating plate is regulated by the first edge portion abutting against the regulating member.

[0010] According to the present invention as described above, even if excessive pressure is applied to the pressure-responsive part and the operating plate loses its supporting relationship with the main body due to the destruction of the fulcrum, the end of the first edge part is pushed up by the lower pressure-responsive part in a state where it is tilted downward, and the first edge part abuts against the regulating member, thereby preventing the operating plate from falling off.

[0011] In this case, it is preferable that a second stopper is provided within the main body at a position on the same side of the first edge portion of the operating plate as the pressure responsive portion, which abuts against the other end side of the first edge portion to regulate the rotational movement of the operating plate.

[0012] It is also preferable that the regulating member is located inside the outer shape of the upper surface of the pressure responding portion.

[0013] The restricting member is preferably a shaft.

[0014] It is also preferable that the restricting member is provided on the other end side relative to the fulcrum.

[0015] Furthermore, it is preferable that the regulating member is provided on the other end side of the position where the pressure responsive portion of the operating plate abuts. Effect of the Invention

[0016] According to the pressure switch of the present invention, even if excessive pressure is applied to the pressure-responsive part, the operating plate is prevented from falling off and pressure resistance is improved, thereby suppressing damage to the pressure-responsive part and preventing leakage of the pressure medium. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a cross-sectional view showing a compression switch according to the embodiment. [Diagram 2] FIG. 4 is a cross-sectional view showing an actuation state of the compression switch of the embodiment. [Diagram 3] FIG. 11 is a cross-sectional view showing a modified compression switch. [Figure 4] 11 is a cross-sectional view showing an actuation state of a compression switch in a modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A pressure switch according to an embodiment of the present invention will be described with reference to Figures 1 and 2. As shown in Figures 1 and 2, the pressure switch 1 of this embodiment includes a box-shaped main body 2 forming an outer shell as a case, a bellows 3 as a pressure responsive part disposed at the bottom of the main body 2, and an L-shaped operating plate 4 that rotates around a fulcrum 2a as an axis by the expansion and contraction of the bellows 3.

[0019] The actuating plate 4 has an L-shape with a vertical side 4a as the second side and a horizontal side 4b as the first side when the first side is disposed horizontally and the second side is disposed vertically relative to the first side. That is, the actuating plate 4 is formed in an L-shape with the vertical side 4a and the horizontal side 4b bent from the bent portion 4c. The actuating plate 4 is disposed with the bellows 3 in contact with the lower part of the horizontal side 4b. The vertical side 4a of the actuating plate 4 is engaged with a spring 5 that opposes the movement of the actuating plate 4 and an actuating shaft 6 that responds to the movement of the actuating plate 4. The spring 5 and the actuating shaft 6 are omitted from FIG. 2 for convenience.

[0020] In this pressure switch 1, one end of the operating shaft 6 is engaged with the vertical side portion 4a of the operating plate 4, and the other end is engaged with a movable contact plate 11 constituting a microswitch 10. The microswitch 10 also includes, for example, two fixed contacts 12A and 12B and a movable contact 13 disposed between them. In the microswitch 10, the movable contact 13 for the fixed contacts 12A and 12B is provided at a free end of the movable contact plate 11. The movable contact plate 11 has a rapid reversal mechanism including a deformation spring 14. The movable contact plate 11 is actuated by the operating plate 4 via the operating shaft 6 to move the movable contact 13 toward and away from the fixed contacts 12A and 12B.

[0021] In this pressure switch 1, when the pressure applied to the bellows 3 increases or decreases, causing the operating plate 4 to rotate about the fulcrum 2a, the movable contact plate 11 operates via the operating shaft 6 which moves in response to the movement of the operating plate 4. As a result, the movable contact plate 11 selectively connects the movable contact 13 between one or two fixed contacts 12A, 12B, and the microswitch 10 is reversed.

[0022] In addition, in the pressure switch 1, a pressure-increasing stopper 2b and a pressure-decreasing stopper 2c that regulate the rotational movement of the actuating plate 4 are provided on the main body 2 at a predetermined interval in the vertical direction near the end of the horizontal side portion 4b of the actuating plate 4. When excessive pressure is applied to the bellows 3, the actuating plate 4 is held by the fulcrum 2a provided on the main body 2 and the pressure-increasing stopper 2b provided at the upper side inside the main body 2, thereby preventing the bellows 3 from stretching.

[0023] In the conventional pressure switch, when the pressure applied to the bellows becomes higher, the bellows expands while tilting, which may cause the operating plate of the main body to tilt. Then, the operating plate, which is no longer supported by the main body, tilts with the end of the horizontal part facing downward and falls on the lower bellows. In some cases, the end of the horizontal part may come off the pressure-down side stopper and fall toward the bottom plate due to the actuation plate being pushed up by the pressure-down side stopper. In this case, not only may the bellows be damaged by the actuation plate falling off, but there is also a risk of leakage of the pressure medium such as the refrigerant.

[0024] Therefore, the pressure switch 1 of this embodiment includes a shaft 7 provided coaxially with the fulcrum 2a near the operating plate 4 inside the main body 2, and a slippage prevention stopper 9 provided at a position on the operating plate 4 closer to the end of the horizontal side portion 4b than the shaft 7. As shown in Fig. 2, when excessive pressure is applied to the bellows 3 and the fulcrum 2a is broken, the slippage prevention stopper 9 comes into contact with the shaft 7.

[0025] Specifically, the axis 7 is located on the opposite side of the bellows 3 on the horizontal edge portion 4b of the operating plate 4 inside the main body 2, on the other end side of the horizontal edge portion 4b across the abutment position of the bellows 3 with respect to the fulcrum 2a, and on the side of the bent portion 4c of the operating plate 4 closer to the anti-slip stopper 9.

[0026] According to the above embodiment, even if excessive pressure is applied to the bellows 3 and the operating plate 4 loses its supporting relationship with the main body 2 due to the destruction of the fulcrum 2a, the end of the horizontal portion 4b is pushed up by the lower bellows 3 with the end tilted downward, and the anti-slip stopper 9 abuts against the axis 7, preventing the operating plate 4 from falling off toward the bottom plate, thereby suppressing damage to the main body 2 and the bellows 3 and improving pressure resistance.

[0027] Furthermore, the shaft 7 is located on the opposite side of the operating plate 4 inside the main body 2 to the bellows 3, diagonally to the fulcrum 2a, and at a position closer to the bent portion 4c of the operating plate 4 than the anti-slip stopper 9 which is above the horizontal side portion 4b of the operating plate 4. Therefore, even if excessive pressure is applied to the bellows 3, causing the bellows 3 to extend while tilting, and thus tilting the operating plate 4 of the main body 2, the anti-slip stopper 9 will accurately abut against the shaft 7, thereby ensuring that the operating plate 4 does not fall off as described above and improving pressure resistance, thereby reliably suppressing damage to the bellows 3 and preventing leakage of the pressure medium.

[0028] Although not shown here, the actuating plate 4 may have a cut-and-raised portion formed on the horizontal side 4b protruding toward the side where the shaft 7 is arranged, and the cut-and-raised portion may function as an anti-slip stopper. In this case, the anti-slip stopper can be easily configured by simply forming a cut-and-raised portion protruding inward on the horizontal side 4b of the actuating plate 4, and there is an advantage in that the anti-slip stopper does not need to be provided as a separate member, allowing the number of parts to be reduced.

[0029] Furthermore, the pressure switch of the present invention is not limited to the above-mentioned embodiment. That is, as shown in Figures 3 and 4, in which the same reference numerals are used for parts corresponding to Figures 1 and 2, the pressure switch may further include a reset plate 20 that is disposed along the upper part of the actuating plate 4, has a bent part 20a at its free end, and is swaged with a rivet 21 to the horizontal side part 4b of the actuating plate 4. Note that the spring 5 in Figure 3 and the spring 5 and actuating shaft 6 in Figure 4 are omitted for convenience.

[0030] In this case, the rivet 21 functions as an anti-slip stopper by engaging with the shaft 7. Although not shown here, the operating plate 4 may have a bent portion protruding inward on the horizontal side portion 4b, and the bent portion may function as an anti-slip stopper.

[0031] According to the above modified example, a reset plate 20 is further provided which is fastened to the horizontal edge portion 4b of the actuating plate 4 using a rivet 21, and the rivet 21 for fixing the reset plate 20 can also be used as an anti-slip stopper. Therefore, in addition to the effects of the above-described embodiment, the effort and cost of providing a stopper can be eliminated.

[0032] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes design changes and the like that do not deviate from the gist of the present invention. [Explanation of symbols]

[0033] 1 Pressure Switch 2 Main unit 2a fulcrum 3 Bellows (pressure response part) 4 Actuating plate 4a Vertical side (second side) 4b Horizontal side (first side) 4c Bend section 4d Cut-out section 5. Spring 6 Working shaft 7-axis 9 Anti-slip stopper 10 Microswitch 11 Movable contact plate 12A, 12B fixed contact 13 Movable contact 14 Deformed spring 20 Reset Plate 21 Rivet 22 Bis

Claims

1. A pressure switch having a pressure responsive portion within a body, an operating plate that abuts against the pressure responsive portion and rotates about a fulcrum provided on the body by the expansion and contraction of the pressure responsive portion, a spring that opposes the movement of the operating plate, an operating shaft that responds to the movement of the operating plate, and a movable contact plate that moves a movable contact with and away from a fixed contact by the movement of the operating shaft, The actuation plate has a first side portion with which the pressure responsive portion abuts, and a second side portion that is continuous with one end side of the first side portion via a bent portion, a restricting member extending in a coaxial direction with the fulcrum and a stopper that restricts a rotational movement of the actuating plate by contacting the other end side of the first side portion of the actuating plate, the restricting member being disposed in a vicinity of the first side portion of the actuating plate on a side opposite to the pressure responsive portion; A pressure switch characterized in that, when excessive pressure is applied to the pressure responsive portion, the first edge portion abuts against the regulating member, thereby regulating movement of the operating plate.

2. The pressure switch as described in claim 1, characterized in that a second stopper is provided within the main body at a position on the same side of the first edge portion of the operating plate as the pressure responsive portion, which abuts against the other end side of the first edge portion to restrict the rotational movement of the operating plate.

3. 3. The pressure switch according to claim 1, wherein the restricting member is located inside an outer shape of an upper surface of the pressure responding portion.

4. 4. The pressure switch according to claim 1, wherein the regulating member is a shaft.

5. 5. The pressure switch according to claim 1, wherein the regulating member is provided on the other end side of the fulcrum.

6. 6. The pressure switch according to claim 1, wherein the regulating member is provided on the other end side of the operating plate relative to a position where the pressure responsive portion abuts against the operating plate.

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