JP4725496B2 - switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively suppress contact failure between fixed terminals and a movable piece which is caused by the abrasion powder produced at a sliding part of a plunger entering a switching operation chamber, in a switch formed by incorporating the movable piece contacted with and separated from the fixed terminals, the plunger supporting the movable piece and slidably displaced, and a spring for return-energizing the plunger into a switch case that has the fixed terminals. <P>SOLUTION: The fixed terminals 6, 7 are disposed facing the switch case 1, and in the switch case 1, the switching operation member 5 is formed in which the movable piece 8 moves, and a sliding contact part, where the switch case 1 and the plunger 2 come relatively into sliding contact with each other; and where the switching operation chamber 5 are separated from each other by barriers 11. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a switch for opening and closing various electric circuits.

Conventionally, for example, in a built-in switch such as a limit switch, a switching mechanism in which a plunger having a movable contact accommodated in a switch case is slid and displaced so that the movable contact comes in contact with and is separated from the fixed contact is incorporated in the switch case ( For example, see Patent Document 1).
JP-A-2005-79041

  In the switch having such a configuration, the sliding contact portion where the switch case and the plunger are in sliding contact with each other and the fixed terminal are provided and the switching operation space in which the movable piece moves is widely communicated. The worn powder easily enters the switching operation space, and there is a possibility that the worn powder that has entered may adhere between the fixed contact and the movable contact, resulting in poor contact.

  The present invention has been made paying attention to such a situation, and provides a switch that can effectively suppress the occurrence of poor contact due to wear powder generated at the sliding portion of the plunger. The purpose is to do.

(1) In the switch of the present invention, a switch case having a fixed terminal, a movable piece that contacts and separates from the fixed terminal, a plunger that slides and displaces the movable piece, and biases the plunger in the sliding direction. A switch incorporating a return spring that forms a switching operation chamber in which the fixed terminal is provided and the movable piece moves, and the switch case and the plunger are in sliding contact with each other. The switching operation chamber is separated by a barrier, the movable piece is supported by the plunger so as to be displaceable in the plunger sliding direction, and the movable piece is pressed against the plunger by the return spring.

According to the present invention, even if wear powder is generated at the sliding contact portion where the switch case and the plunger are in sliding contact with each other, the barrier prevents the wear powder from entering the switching operation chamber. It is possible to prevent contact failure due to wear powder adhering between them.
According to the present invention, the return spring can also be used as a spring that presses and holds the movable piece at a predetermined position of the plunger, so that the number of parts and assembly man-hours can be reduced.

  (2) In one embodiment of the switch of the present invention, the plunger may be slidably guided by a guide groove and a protrusion engaged therewith.

  According to this embodiment, it is easy to use the wall on the switching operation chamber side in the guide groove as a barrier for isolating the sliding contact portion and the switching operation chamber, and the flow of the wear powder without the need to form a dedicated barrier Can be suppressed.

  In addition, the generation of wear powder can be concentrated and stay in the narrow guide groove.For example, the plunger is slid in a structure in which the wide flat outer surface of the plunger formed in a block shape is slidably contacted with the inner surface of the switch case. Compared to the case of moving and guiding, the diffusion of the wear powder is prevented and it is difficult to move to the switching operation chamber.

  (3) In the embodiment of the above (2), the guide groove may be formed in the switch case, and the protrusion may be formed in the plunger.

  According to this embodiment, the projection also functions as a rib for increasing the rigidity of the plunger, the shape accuracy of the plunger is maintained high, and the sliding operation can be smoothly performed over a long period of time.

  (4) In the embodiment of the above (2) or (3), a concave portion for accommodating wear powder may be formed on the inner surface of the guide groove.

  According to this embodiment, the generated wear powder is accumulated in the recess, the outflow from the guide groove is suppressed, and the intrusion of the wear powder into the switching operation chamber can be more effectively suppressed. In particular, when lubricating oil is applied to the sliding contact portion, generation of wear powder is suppressed, and the generated wear powder tends to stop in the recess through the lubricating oil.

  As described above, according to the present invention, it is possible to effectively suppress the abrasion powder generated at the sliding portion of the plunger from entering between the fixed terminal and the movable piece and causing poor contact. A switch can be provided.

Hereinafter, some examples and reference examples of the present invention will be described with reference to the drawings.

[First example]
1 to 8 show a first example as a reference example of a switch according to the present invention.

  1 is an overall perspective view of the switch of the first example viewed from the front side, FIG. 2 is an overall perspective view viewed from the back side, FIG. 3 is a transverse plan view, and FIG. FIG. 5 is a longitudinal front view showing the switching mechanism, FIG. 6 is an xx sectional view in FIG. 3, FIG. 7 is a longitudinal side view, and FIG. 8 is a longitudinal front view. .

  In this switch, a plunger 2 that is slidable up and down in a switch case 1, a switching mechanism 3 shown in FIG. 5 that is contacted and separated by the vertical movement of the plunger 2, and the plunger 2 in a predetermined direction (in this example) A coil-type return spring 4 that is biased upward) is assembled.

  The switch case 1 includes a case main body 1a and a front case 1b joined and connected to the front surface thereof. The engaging claws 1c extending from the left and right ends of the case main body 1a are connected to the left and right outer surfaces of the front case 1b. The case main body 1a and the front case 1b are joined and connected to each other by engaging with a protrusion 1d provided on the front case 1b. The case main body 1a is formed in a box shape with an open front surface, and its internal space is a switching operation chamber 5 that houses the switching mechanism 3 as shown in FIGS.

  The switching mechanism 3 includes a pair of left and right fixed terminals 6 and 7 that are insert-fixed to the back wall of the case body 1a with appropriate insulation intervals, and fixed contacts 6a and 7a that are provided at the ends of the fixed terminals 6 and 7. A movable piece 8 made of a conductive metal plate provided with movable contacts 8a and 8b facing from below is provided on both left and right sides, and the plunger 2 supporting the movable piece 8 is slid upwardly by a return spring 4. Thus, the upper end of the plunger 2 protrudes from the upper surface of the switch case 1 and the fixed terminals 6 and 7 protrude from the rear surface of the switch case 1 so that an external conductor is connected.

  On both the left and right sides of the plunger 2, long and straight linear protrusions 9 are provided, and on the left and right inner surfaces of the front case 1b, linear guide grooves 10 for engaging the protrusions 9 so as to be movable up and down are formed. The plunger 2 is supported by the guide grooves 10 and the protrusions 9 so as to be slidable in the vertical direction. Lubricating oil is applied to the protrusion 9 of the plunger 2 to reduce the sliding resistance at the sliding portion and to suppress the occurrence of wear at the sliding contact portion.

  A wall on the inner side of the case in the guide groove 10 is configured as a barrier 11 that separates the sliding contact portion of the plunger 2 from the switching operation chamber 5, and wear powder generated at the sliding contact portion is generated in the switching operation chamber 5. Intrusion is suppressed by the barrier 11.

  As shown in FIG. 4, a groove-like recess 12 extending in the vertical direction is formed on the inner surface of the guide groove 10 on the inlet side, and wear powder generated inside the guide groove 10 enters the recess 12 and is stored. It has come to be.

  As shown in FIGS. 7 and 8, a vertically long recessed space 14 opened forward is formed on the forward-facing side surface of the plunger 2, and the return spring 4 is accommodated in the recessed space 14, and The upper end of the return spring 4 is received by a step portion 15 formed at the upper end portion of the entrance space 14, and the elastic restoring force of the return spring 4 is configured to act upward on the plunger 2.

  A spring support portion 16 having a width smaller than the outer diameter of the return spring 4 protrudes from the lower inner surface of the front case 1b, and an opening 17 having a width smaller than the width of the recessed space 14 is formed on the front side of the lower end of the plunger 2. Is formed. The opening 17 is formed in a width that allows the spring support 16 to pass vertically, and the return spring 4 is pre-assembled in the recessed space 14, and then the plunger 2 and the front case 1b in which the return spring 4 is incorporated. Are assembled from the longitudinal direction of the plunger so that the spring support portion 16 is inserted from below through the opening 17 formed at the lower end of the recessed space 14, and the lower end of the return spring 4 is spring-supported while compressively deforming the return spring 4 upward. It can be supported by the part 16.

  By connecting the front case 1b incorporating the plunger 2 to the front surface of the case main body 1a, it is possible to obtain a switch in which the plunger 10 can be slid up and down and protruded above the case.

  The movable piece 8 constituting the switching mechanism 3 is supported on the plunger 2 as follows. That is, as shown in FIGS. 5 to 7, a concave portion 18 opened rearward is formed at an upper and lower intermediate portion of the plunger 2, and a support pin 19 protrudes downward from a downward surface 18 a of the concave portion 18. The movable piece 8 is inserted into the support pin 19 from below through the through hole 20, and a spring 21 is interposed between the movable piece 8 and the upward surface of the recess 18. It is biased upward and pressed against the fixed terminals 6 and 7.

  As shown in FIG. 5A, the switching mechanism 3 in this example is a normally closed contact (b) in which both the fixed terminals 6 and 7 are conducted through the movable piece 8 in a state where the plunger 2 is returned upward. Contact) specification, and the plunger 2 is pushed and slid and displaced against the return spring 4 and moved downward more than the gap formed between the movable piece 8 and the downward surface 18a of the recess 18. Thus, as shown in FIG. 5B, the movable piece 8 pressed and held against the downward surface 18a of the recess 18 by the spring 21 is separated from both the fixed terminals 6 and 7, and the conduction between the fixed terminals 6 and 7 is established. I will be refused.

[Second example]
9 to 12 show a second example of the switch according to the present invention.

  9 is an overall perspective view of the switch of the second example, FIG. 10 is a transverse plan view, FIG. 11 is a yy sectional view in FIG. 10, and FIG. 12 shows the switching mechanism of the switch. It is a longitudinal front view shown.

  The switch of this example is also configured to have a normally closed contact (b contact) specification as in the first example. In this example, the movable piece 8 is inserted and supported from below through the support pin 19 provided in the concave portion 18 through a through hole, and between the spring support portion 16 provided at the bottom of the switch case 1. The return spring 4 is assembled, the movable piece 8 is pressed against the downward surface 18a of the recess 18 by the return spring 4, and the plunger 2 is urged upward by the return spring 4.

  The switch case 1 in this example is composed of a box-shaped case main body 1a and an upper cover 1e fitted and fixed to the upper end thereof. The movable piece 8 and the return spring 4 are assembled to the plunger 2 in advance. After assembling the assembled plunger 2 into the case body 1a from above, the fixed terminals 6 and 7 are press-fitted into the case body 1a from above, and then the upper cover 1e is fitted and fastened to the upper end of the case body 1a. The switch is completed.

  Also in this example, as shown in FIG. 10, the inner wall of the case in the guide groove 10 is configured as a barrier 11 that separates the sliding contact portion of the plunger 2 from the switching operation chamber 5. The barrier 11 prevents the wear powder generated at the site from entering the switching operation chamber 5.

[Third example]
FIGS. 13 to 16 show a third example as a reference example of the switch according to the present invention.

  13 is an overall perspective view of the switch of the third example as seen from the front side, FIG. 14 is an overall perspective view as seen from the back side, FIG. 15 is a transverse plan view, and FIG. FIG.

  As in the first example, the switch in this example supports the plunger 2 so as to be slidable up and down through the case main body 1a in which the switching operation chamber 5 is formed, the guide groove 10, and the protrusion 9. The plunger 2 is configured to be joined and connected to the case 1b, and the plunger 2 is urged and projected above the case by a return spring 4 having the same structure as that of the first example and built in the front case.

  The switching mechanism 5 housed in the switching operation chamber 5 is slid into three fixed terminals 25, 26, 27 arranged in parallel to the left and right to be substantially flush with the inner surface of the case, and the fixed terminals 25, 26, 27. The movable piece 8 includes three contact pieces 8c, 8d, and 8e that are brought into contact with and separated from each other, and is fixed to the back surface of the plunger 2 by caulking. Here, the fixed terminal 26 at the center is a common terminal that is always in contact with the contact 8d regardless of the sliding displacement of the plunger 2, and one fixed terminal 25 is when the plunger 2 is returned to the upper position. When the contact 8c is brought into contact conduction and the plunger 2 moves downward, the contact 8c becomes a normally closed terminal, and the other fixed terminal 27 is disconnected when the plunger 2 is returned to the upper position. When the plunger 2 moves downward, the contact 8e becomes a normally open terminal that conducts contact.

  Also in this example, as shown in FIG. 15, the wall on the inner side of the case in the guide groove 10 is configured as a barrier 11 that separates the sliding contact portion of the plunger 2 from the switching operation chamber 5. The barrier 11 prevents the wear powder generated at the site from entering the switching operation chamber 5. Furthermore, a groove-like recess 12 extending in the vertical direction is formed on the inner surface of the guide groove 10 on the inlet side, and wear powder generated inside the guide groove 10 enters the recess 12 and is stored. .

[Other Examples]
(1) Contrary to the above-described embodiment, the projection 9 for slidingly guiding the plunger 2 may be formed on the switch case 1 and the guide groove 10 for engaging the projection 9 may be formed on the plunger 2. .

  (2) The protrusions 9 may be formed as long protrusions as in the above embodiment, or may be formed as protrusions that are short in the sliding direction to be engaged in a plurality of locations in the guide groove 10.

  (3) In the first and second examples, the normally closed contact type switch is illustrated, but the return spring 4 may be assembled to the plunger in the reverse direction so that the normally open contact type is configured. it can.

  (4) In each of the above embodiments, the wall on the switching operation chamber side of the guide groove 10 is used as the barrier 11, but the dedicated barrier 11 is provided between the sliding contact portion and the switching operation chamber. You can also.

  (5) The switch of the present invention can be used as a contact module in addition to being used as a single throw single pole type independent switch. For example, an appropriate number of switches configured for a normally closed contact specification and an appropriate number of switches configured for a normally open contact specification are assembled in a large switch case in parallel so that each plunger 2 protrudes upward. The plunger 2 of each switch is placed opposite to the free end of the movable actuator, the actuator is swung by pushing the push button, etc., and all the plungers 2 are pushed to switch the switches at the same time. It can also be configured and implemented so that the respective switches can be reset simultaneously by being released.

  The present invention is useful as various switches.

It is the whole perspective view which looked at the switch of the 1st example from the front side. It is the whole perspective view which looked at the switch of the 1st example from the back side. It is a cross-sectional plan view of the switch of the first example. It is the cross-sectional top view to which the principal part of the switch of the 1st example was expanded. It is a vertical front view which shows the switching mechanism of the switch of a 1st example. It is xx sectional drawing in FIG. It is a vertical side view of the switch of the 1st example. It is a vertical front view of the switch of the 1st example. It is a whole perspective view of the switch of the 2nd example. It is a cross-sectional plan view of the switch of the second example. It is yy sectional drawing in FIG. It is a vertical front view which shows the switching mechanism of the switch of a 2nd example. It is the whole perspective view which looked at the switch of the 3rd example from the front side. It is the whole perspective view which looked at the switch of the 3rd example from the back side. It is a cross-sectional plan view of the switch of the third example. It is zz sectional drawing in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Switch case 2 Plunger 3 Switching mechanism 4 Return spring 5 Switching operation chamber 6 Fixed terminal 7 Fixed terminal 8 Movable piece 9 Protrusion 10 Guide groove 11 Barrier 12 Recessed part 25 Fixed terminal (normally closed terminal)
26 Fixed terminal (common terminal)
27 Fixed terminal (normally open terminal)

Claims (4)

A switch in which a switch case having a fixed terminal is assembled with a movable piece contacting and separating from the fixed terminal, a plunger that slides and displaces the movable piece, and a return spring that biases the plunger in the sliding direction. There,
In the switch case, the fixed terminal is provided and a switching operation chamber in which the movable piece moves is formed, and a sliding contact portion where the switch case and the plunger are in sliding contact with each other is separated from the switching operation chamber by a barrier. Oh it is,
The switch is characterized in that the movable piece is supported by the plunger so as to be displaceable in the plunger sliding direction, and the movable piece is pressed against the plunger and held by the return spring .   The switch according to claim 1, wherein the plunger is slidably guided by a guide groove and a protrusion inserted into the guide groove.   The switch according to claim 2, wherein the guide groove is formed in a switch case, and the protrusion is formed in a plunger.   The switch according to claim 2 or 3, wherein a concave portion for accommodating wear powder is formed on an inner surface of the guide groove.

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