Pressure switch

Abstract

The invention provides a pressure switch which can prevent a working plate from falling off and improve pressure resistance even under the condition that excessive pressure is applied to a pressure follow-up part, thereby inhibiting damage of the pressure follow-up part and preventing leakage of a pressure medium. A pressure switch (1) is provided with: a stopper shaft (7) provided in a direction parallel to the axial direction of a fulcrum (2a) in the vicinity of a working plate (4) in a main body (2); and a displacement prevention stopper (9) which is provided on the working plate (4) at a position closer to the end of the lateral side section (4b) than the stopper shaft (7), and which restricts the movement of the working plate (4) by the displacement prevention stopper (9) coming into contact with the stopper shaft (7) even when excessive pressure is applied to the bellows (3).

Description

[0001] This invention is a divisional application of the invention application with application number 202210640246.X, invention name "Pressure Switch" and application date June 7, 2022. Technical Field

[0002] The present invention relates to a pressure switch. Background Art

[0003] Conventionally, a pressure switch has been known that includes, within a main body, a bellows serving as a pressure follower; an L-shaped working plate that rotates about a fulcrum provided on the main body as an axis due to the expansion and contraction of the bellows; a spring connected to a longitudinal side of the working plate to resist the movement of the working plate; a working shaft that follows the movement of the working plate; and a movable contact plate that controls the microswitch through the movement of the working shaft (for example, see Patent Documents 1 and 2).

[0004] In this pressure switch, one end of the operating shaft engages with a longitudinal edge of the operating plate, while the other end engages with a movable contact plate constituting a microswitch. Furthermore, the microswitch comprises, for example, two fixed contacts and a movable contact disposed between them. In the microswitch, the movable contact, which is opposite the fixed contacts, is located at the free end of the movable contact plate. The movable contact plate has a quick reversal mechanism including a deformation spring.

[0005] Furthermore, in such conventional pressure switches, when the operating plate rotates about the fulcrum due to increases or decreases in pressure applied to the bellows, the movable contact plate moves via the operating shaft, which follows the movement of the operating plate. As a result, the movable contact plate selectively connects the movable contact to one or both fixed contacts, reversing the microswitch.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Utility Model Application Laid-Open No. 50-9571

[0009] Patent Document 2: Japanese Utility Model Application Laid-Open No. 61-193647 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] However, in the conventional pressure switches described in Patent Documents 1 and 2, pressure-increasing and pressure-decreasing stoppers are provided on the main body at predetermined intervals in the vertical direction near the ends of the lateral sides of the working plate (Patent Document 1 includes only the latter). Furthermore, if excessive pressure is applied to the bellows, the working plate is held in place by the pressure-increasing stopper, located at a fulcrum on the main body and located on the upper side of the main body, thereby preventing the bellows from extending.

[0012] However, in such conventional pressure switches, if the pressure applied to the bellows increases further, the bellows tilts and stretches, potentially tilting the operating plate of the main body. Consequently, the operating plate, no longer supported by the main body, is pushed upward by the bellows below while the ends of its lateral sides tilt downward. This can cause the ends of the lateral sides to disengage from the pressure-reducing side stoppers and fall toward the base plate. In this case, the detachment of the operating plate could damage the bellows and potentially lead to leakage of pressure media such as refrigerant.

[0013] An object of the present invention is to provide a pressure switch that can improve pressure resistance by preventing a working plate from falling off even when excessive pressure is applied to a pressure follower, thereby suppressing damage to the pressure follower and preventing leakage of a pressure medium.

[0014] Solutions to Problems

[0015] The pressure switch of the present invention comprises, in a main body, a pressure follower; an operating plate abutting against the pressure follower and rotating about a fulcrum provided on the main body by extension and contraction of the pressure follower; a spring opposing the movement of the operating plate; an operating shaft following the movement of the operating plate; and a movable contact plate causing the movable contact to contact and separate with respect to a fixed contact by movement of the operating shaft, wherein the operating plate comprises a first side abutting against the pressure follower; and a second side continuous with one end side of the first side via a bent portion; a limit shaft parallel to the axial direction of the fulcrum near the first side of the operating plate is provided in the main body; an anti-deviating stopper is provided on the operating plate, the anti-deviating stopper being located closer to the other end side of the first side than the limit shaft; when excessive pressure is applied to the pressure follower, the anti-deviating stopper abuts against the limit shaft, thereby limiting the movement of the operating plate.

[0016] According to the present invention described above, even when excessive pressure is applied to the pressure follower and the supporting relationship between the working plate and the main body is lost due to the destruction of the fulcrum, the end of the first side portion is pushed up by the pressure follower below when the end portion is tilted downward. Therefore, the anti-deviating stopper abuts against the limit shaft, thereby preventing the working plate from falling toward the bottom plate, suppressing damage to the main body and the pressure follower, and improving pressure resistance.

[0017] At this time, it is preferred that the limit axis is arranged at a position on the first side of the working plate opposite to the pressure follower, and this position is located on the other end side of the first side relative to the abutment position of the pressure follower separated by the fulcrum, and is closer to the bending portion side of the working plate than the anti-deviation stopper.

[0018] According to this structure, even if excessive pressure is applied to the pressure follower and the supporting relationship between the working plate and the main body is lost due to the destruction of the fulcrum, the anti-drift stopper can reliably abut against the limit shaft, thereby reliably preventing the above-mentioned working plate from falling off, and reliably suppressing damage to the main body and the pressure follower, thereby further improving the pressure resistance.

[0019] In addition, it is also possible to further include a reset plate, which is arranged along the surface of the working plate on the side opposite to the pressure follower side, has a bent portion at the free end, and is press-fitted to the first side of the working plate using a rivet, and the rivet functions as the anti-drift stopper by being locked with the limit shaft.

[0020] According to this configuration, the rivets used for fixing the reset plate can be used as the anti-deviating stoppers, thereby saving the time and cost of providing the stoppers.

[0021] Furthermore, the operation plate may include a cut-and-raised portion on the first side portion that protrudes toward the side where the stopper shaft is disposed, and the cut-and-raised portion may function as the anti-drift stopper.

[0022] According to this structure, only by forming the protruding cut-and-raised portion toward the configuration side of the limit shaft at the first side of the working plate, the anti-deviation stopper can be simply constituted. In addition, the anti-deviation stopper does not need to be provided in the mode of other components, and parts can be reduced.

[0023] Furthermore, for example, a screw for adjusting the return position of the operation plate may be further provided, and the range of the rotational movement of the operation plate may be restricted by the return position adjustment of the operation plate by the screw.

[0024] According to this configuration, the rotational movement of the working plate is restricted by adjusting the return position with the screw, and the tilt is reduced, so that the working plate is less likely to fall off toward the bottom plate.

[0025] Effects of the Invention

[0026] According to the pressure switch of the present invention, even when excessive pressure is applied to the pressure follower, the operating plate is prevented from falling off, thereby improving pressure resistance, suppressing damage to the pressure follower, and preventing leakage of the pressure medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view showing a compression switch according to the embodiment.

[0028] Figure 2 It is a cross-sectional view showing an operating state of the compression switch according to the embodiment.

[0029] Figure 3 It is a cross-sectional view showing a compression switch according to a modified example.

[0030] Figure 4 It is a cross-sectional view showing an operating state of a compression switch in a modified example.

[0031] In the picture:

[0032] 1—pressure switch; 2—main body; 2a—fulcrum; 3—bellows (pressure follower); 4—working plate; 4a—longitudinal edge (second edge); 4b—transverse edge (first edge); 4c—bending portion; 5—spring; 6—working shaft; 7—limiting shaft; 9—anti-drift stop; 10—micro switch; 11—movable contact plate; 12A, 12B—fixed contacts; 13—movable contact; 14—deformation spring; 20—reset plate; 21—rivet; 22—screw. DETAILED DESCRIPTION

[0033] Reference Figure 1 and Figure 2 The pressure switch according to the embodiment of the present invention will be described. Figure 1 as well as Figure 2 As shown, the pressure switch 1 of this embodiment comprises: a box-shaped main body 2, which constitutes the outer contour of the shell; a bellows 3 as a pressure follower, which is arranged at the bottom of the main body 2; and an L-shaped working plate 4, which rotates around the fulcrum 2a as the axis through the expansion and contraction of the bellows 3.

[0034] The working plate 4 is in an L-shape with a first side portion being arranged in a horizontal direction as a side abutting the bellows 3 and a second side portion being arranged in a vertical direction upright relative to the first side portion. That is, the longitudinal side portion 4a and the transverse side portion 4b of the working plate 4 are formed into an L-shape bent with the bending portion 4c as a starting point. The working plate 4 is abutted against the bellows 3 at the lower portion of the transverse side portion 4b. In addition, a spring 5 that counteracts the movement of the working plate 4 and a working shaft 6 that follows the movement of the working plate 4 are engaged with the longitudinal side portion 4a of the working plate 4. In addition, Figure 2 In the figure, the spring 5 and the working shaft 6 are omitted for the sake of convenience.

[0035] In this pressure switch 1, one end of the operating shaft 6 engages with the longitudinal side 4a of the operating plate 4, and the other end engages with the movable contact plate 11 that constitutes the microswitch 10. Furthermore, the microswitch 10 includes, for example, two fixed contacts 12A and 12B and a movable contact 13 disposed therebetween. In the microswitch 10, the movable contact 13 is disposed at the free end of the movable contact plate 11 relative to the fixed contacts 12A and 12B. The movable contact plate 11 includes a quick reversal mechanism including a deforming spring 14. The movable contact plate 11 receives movement of the operating plate 4 via the operating shaft 6, thereby causing the movable contact 13 to come into and out of contact with the fixed contacts 12A and 12B.

[0036] Furthermore, in this pressure switch 1, when the operating plate 4 rotates about the fulcrum 2a by increasing or decreasing the pressure applied to the bellows 3, the movable contact plate 11 moves via the operating shaft 6, which follows the movement of the operating plate 4. As a result, the movable contact plate 11 causes the movable contact 13 to selectively connect to one or both of the fixed contacts 12A and 12B, and the microswitch 10 reverses.

[0037] Furthermore, in the pressure switch 1, a pressure-increasing stopper 2b and a pressure-decreasing stopper 2c are provided on the main body 2 near the ends of the lateral side 4b of the operating plate 4 at predetermined intervals in the vertical direction to restrict the rotational movement of the operating plate 4. Furthermore, if excessive pressure is applied to the bellows 3, the operating plate 4 is held in place by the fulcrum 2a provided on the main body 2 and the pressure-increasing stopper 2b, located above the side of the main body 2, thereby preventing the bellows 3 from extending.

[0038] In conventional pressure switches, as the pressure applied to the bellows increases, the bellows stretches while tilting, causing the working plate of the main body to tilt. Furthermore, the working plate, no longer supported by the main body, is pushed upward by the bellows below, with the ends of its lateral sides tilted downward. This can cause the ends of the lateral sides to disengage from the pressure-reducing stoppers and fall toward the base plate. In this case, the detachment of the working plate can damage the bellows and potentially leak refrigerant or other pressure media.

[0039] Therefore, the pressure switch 1 of this embodiment includes: a limit shaft 7, which is provided in a direction parallel to the axial direction of the fulcrum 2a near the working plate 4 in the main body 2; and an anti-drift stopper 9, which is provided at a position closer to the end of the horizontal side portion 4b of the working plate 4 than the limit shaft 7. Figure 2 As shown, when excessive pressure is applied to the bellows 3 and the fulcrum 2 a is broken, the anti-deviating stopper 9 abuts against the limiting shaft 7 .

[0040] Specifically, the limit shaft 7 is arranged at a position on the opposite side of the bellows 3 of the lateral side 4b of the working plate 4 in the main body 2, and is arranged at the other end side of the lateral side 4b relative to the abutment position of the bellows 3 relative to the fulcrum 2a, and is arranged at a position closer to the bent portion 4c of the working plate 4 than the anti-deviation stopper 9.

[0041] According to the present embodiment described above, even when excessive pressure is applied to the bellows 3 and the supporting relationship between the working plate 4 and the main body 2 disappears due to the destruction of the fulcrum 2a, the end of the horizontal side portion 4b is pushed up by the bellows 3 below when the end portion is tilted downward. Therefore, the anti-drift stopper 9 abuts against the limit shaft 7, thereby preventing the working plate 4 from falling off toward the bottom plate, suppressing damage to the main body 2 and the bellows 3, and improving pressure resistance.

[0042] In addition, the limit shaft 7 is arranged at a position on the opposite side of the working plate 4 in the main body 2 to the bellows 3, and is arranged at a position on the diagonal line relative to the fulcrum 2a and on the side of the bent portion 4c of the working plate 4 compared to the anti-deviation stopper 9 above the lateral side 4b of the working plate 4. Therefore, even if excessive pressure is applied to the bellows 3 and the working plate 4 of the main body 2 tilts due to the bellows 3 extending while tilting, the anti-deviation stopper 9 can reliably abut against the limit shaft 7, thereby reliably preventing the above-mentioned working plate 4 from falling off and improving the pressure resistance. As a result, damage to the bellows 3 can be reliably suppressed and leakage of the pressure medium can be prevented.

[0043] Although not shown here, the work plate 4 may also be provided with a raised portion protruding toward the side of the lateral side 4b where the stopper shaft 7 is located, so that the raised portion functions as an anti-drifting stop. In this case, the anti-drifting stop can be simply formed by simply forming the raised portion protruding inwardly on the lateral side 4b of the work plate 4. Furthermore, the anti-drifting stop does not need to be provided with a separate component, thereby reducing the number of components.

[0044] In addition, the pressure switch of the present invention is not limited to the above-mentioned embodiment. Figure 1 、 Figure 2 The corresponding parts are marked with the same symbols Figure 3 、 Figure 4 As shown, it is also possible to further include a reset plate 20, which is arranged along the upper part of the working plate 4 and has a bent portion 20a at the free end, and is pressed against the horizontal side portion 4b of the working plate 4 using a rivet 21. In addition, for convenience, the Figure 3 Spring 5 and Figure 4 The spring 5 and the working shaft 6 in it.

[0045] In this case, the rivet 21 functions as an anti-deviation stopper by being locked with the limit shaft 7. In addition, although not shown in the figure, the working plate 4 may also have a cut-and-raised portion protruding inwardly at the horizontal side portion 4b so that the cut-and-raised portion functions as an anti-deviation stopper.

[0046] According to the above modified example, the reset plate 20 is further provided, which is press-fitted to the lateral side portion 4b of the working plate 4 using the rivet 21. Since the rivet 21 used to fix the reset plate 20 can be used as an anti-drifting stopper, in addition to the effects of the above embodiment, the time and cost of providing the stopper can be saved.

[0047] While the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments and design changes that do not depart from the spirit of the present invention are also included in the present invention.

Claims

1. A pressure switch comprising: a pressure follower; an operating plate in contact with the pressure follower and capable of rotating about a fulcrum provided on the main body by the expansion and contraction of the pressure follower; a spring for resisting the movement of the operating plate; an operating shaft for following the movement of the operating plate; and a movable contact plate for causing a movable contact to contact and separate from a fixed contact by the movement of the operating shaft. The pressure switch is characterized in that The working plate includes: a first side portion that contacts the pressure follower; and a second side portion that is continuous with one end of the first side portion via a bent portion. In the main body, a limiting member is provided in parallel with the fulcrum in the axial direction at a position near the first side of the working plate on the side opposite to the pressure follower. When an excessive pressure is applied to the pressure follower, the first side portion contacts the restriction member, thereby restricting the movement of the operation plate.

2. The pressure switch according to claim 1, characterized in that The restriction member is located inside the outer shape of the upper surface of the pressure follower.

3. The pressure switch according to claim 1, characterized in that The limiting component is a shaft.

4. The pressure switch according to claim 1, characterized in that The restriction member is provided on the other end side of the first side portion relative to the fulcrum.

5. The pressure switch according to claim 1, characterized in that: The restriction member is provided on the other end side of the first side portion relative to a position of the working plate in contact with the pressure follower.

6. A pressure switch comprising: a pressure follower in a main body; a working plate having an insertion hole through which a fulcrum provided on the main body is rotatably inserted, and rotating about the fulcrum by the expansion and contraction of the pressure follower; a spring that opposes the movement of the working plate; a working shaft that follows the movement of the working plate; and a movable contact plate that causes a movable contact to contact and separate from a fixed contact by the movement of the working shaft. The pressure switch is characterized in that The working plate includes: a first side portion having a contact portion that contacts the pressure follower portion; and a second side portion that is continuous with one end of the first side portion via a bent portion. In a non-pressurized state of the pressure switch, the contact portion is located within a range of an opening of the insertion hole in the extension and contraction direction of the pressure follower.

7. The pressure switch according to claim 6, characterized in that: The insertion hole is located inside the outer shape of the upper surface of the pressure follower.

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