Travel switch

Abstract

The utility model relates to a button switch in which a contact recovers to an initial state after an operating force is eliminated, in particular to a travel switch. According to the utility model, the conventional travel switch is improved, the sealing structure between the feeler lever and the switch shell is optimized, and the layer of sealing between the feeler lever and the feeler lever through hole at the outer side is set as the spring seal, so that large pressure difference and temperature difference inside and outside the switch shell are realized by means of the spring seal; and the travel switch can still ensure a better sealing effect in complex flight environments such as higher motion acceleration and the like, so that the reliability of the travel switch is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to the button switch of contact point is restored initial state when operating force is eliminated, especially travel switch. BACKGROUND

[0002] Travel switch as a kind of position detection sensing element is widely applied in many fields in industrial production.Majority travel switch on market has no special sealing requirement, and the lever is extended from the front side of switch housing, and the signal triggering of travel switch is realized when being pressed back by other components, and there is no special sealing structure between the lever and switch housing.This kind of travel switch is applied to some special occasions, such as used to detect whether airplane suspension is launched by position change, since airplane flight height, speed and attitude are changeable, impurities such as dust, smoke and water mist are easy to enter switch housing through the gap between the lever and switch housing, which will affect the internal contact of switch housing, such as poor contact or false contact, etc., which will lead to the generation of error signal and cause great influence.

[0003] In order to meet the needs of some use occasions, there is prior art to disclose travel switch with sealing structure between lever and switch housing, such as a kind of sealed travel switch for underwater use disclosed by Chinese patent application for invention with application publication number CN118588476A, which is provided with double-layer sealing structure between push rod, i.e. lever and switch housing, and one layer is O-ring sealing, and one layer is rectangular sealing ring sealing, to ensure the sealing isolation between inside and outside of switch housing during the extension and retraction of lever.But this kind of travel switch is mainly aimed at sealing in underwater environment, and the pressure and temperature change between inside and outside of switch housing in underwater environment is not obvious, and the motion acceleration has no great mutation, which is quite different from the use environment of airborne equipment.When this kind of travel switch is applied to airborne equipment, the sealing reliability is still insufficient. CONTENT OF UTILITY MODEL

[0004] The utility model aims at providing a kind of travel switch, to solve the problem of insufficient sealing performance between the preliminary draft of existing travel switch and switch housing, which leads to insufficient reliability of travel switch.

[0005] The travel switch of the utility model includes switch housing, switch main body and lever, lever is slidably worn in the lever through-hole of switch housing, one end of lever in switch housing cooperates with switch main body, sealing structure is arranged between lever and the inner wall of lever through-hole, and the sealing structure includes flood seal, and the flood seal is located at the outer side of lever through-hole.

[0006] Further, the sealing structure further includes O-shaped sealing ring inside the flood seal.

[0007] Further, the switch body comprises a body shell and a floating short-circuit structure installed in the body shell, the floating short-circuit structure comprises a short-circuit piece and a retaining spring providing elastic force to the short-circuit piece towards the side of the contact lever, and a pair of wiring terminals are fixedly installed in the body shell, the wiring terminals have contact portions at the front side of the short-circuit piece, the retaining spring pushes the short-circuit piece in the natural state and keeps the short-circuit piece in abutment with the contact portions of the two wiring terminals to turn on the two wiring terminals, in the process of the contact lever moving backwards under force, the contact lever pushes back the short-circuit piece to make it separate from the two wiring terminals, and the two wiring terminals are turned off.

[0008] Further, the contact portion is an elastic terminal elastically deformed in the front-back direction, and the elastic terminal is installed in the body shell with the rear end elastically abutting against the short-circuit piece.

[0009] Further, the elastic terminal is a snap contact or a spring needle.

[0010] Further, the wiring terminal further comprises a wiring piece extending away from the contact lever, the rear end of the wiring piece is a wiring end, and the front end of the wiring piece is electrically connected with the front end of the contact portion.

[0011] Further, the wiring piece is an L-shaped contact piece, one straight edge of the L-shaped contact piece extends in the front-back direction and the rear end is the wiring end, and the other straight edge extends towards the contact portion and is connected with the front end of the contact portion in front-back abutment.

[0012] Further, the body shell is a split inner shell, the split inner shell comprises a cylindrical inner shell with an open front end and a front inner shell blocking the front end of the cylindrical inner shell, the floating short-circuit structure is installed in an inner shell installation cavity surrounded by the cylindrical inner shell and the front inner shell, the contact portion is fixedly installed in the front inner shell with the rear end exposed to the inner shell installation cavity, and the front inner shell is provided with a transmission avoiding hole for the action of the contact lever to be transmitted to the short-circuit piece.

[0013] Further, the front inner shell is provided with a wiring piece installation hole for the front-back extending straight edge of the L-shaped contact piece to be installed in, the front side of the front shell body is further provided with an installation sunken groove, the other straight edge of the L-shaped contact piece is located in the installation sunken groove, and the split inner shell further comprises a front blocking plate at the front end of the front inner shell for pressing and fixing the L-shaped contact piece in the front shell body.

[0014] Further, the switch shell comprises a cylindrical outer shell, the contact lever is movably installed in the cylindrical outer shell, the inner cavity of the cylindrical outer shell has a rear inner step surface, the split inner shell is installed in the inner cavity of the cylindrical outer shell with the front blocking plate abutting against the inner step, and the inner cavity of the cylindrical outer shell is further provided with a stop ring stopping the split inner cavity from the rear side.

[0015] Further, the short-circuit piece is connected with a guide pin at the front side, the guide pin is guided and matched with the transmission avoiding hole, and the rear end of the contact lever extends into the transmission avoiding hole and transmits the drive to the short-circuit piece through the guide pin.

[0016] Further, a gap is reserved between the rear end of the touch rod and the guide pin.

[0017] The utility model discloses an improved travel switch, which optimizes the sealing structure between the touch rod and the switch shell, sets the outer layer sealing between the touch rod and the touch rod perforation as a flood seal, and realizes a large pressure difference and temperature difference between the inside and outside of the switch shell by means of the flood seal. The travel switch can still guarantee good sealing effect and reliability under complex flight environment with large movement acceleration. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 It is a perspective view of an embodiment of the travel switch of the utility model;

[0019] Fig. 2 It is a tail part schematic view of the travel switch of the utility model;

[0020] Fig. 3 It is a cross-sectional view of the travel switch of the utility model after the installation flange is hidden.

[0021] In the figure: 31, touch rod; 32, reset spring; 310, outer flange; 311, trigger end; 43, short-circuit piece; 44, gap; 45, cylindrical shell; 46, check ring; 47, front end plate; 48, flood seal ring; 49, O-shaped sealing ring; 401, cylindrical inner shell; 402, front inner shell; 403, front blocking plate; 410, L-shaped contact piece; 411, elastic terminal; 430, retaining spring; 431, guide pin; 4101, another straight edge; 50, installation flange. DETAILED DESCRIPTION

[0022] The features and performance of the utility model are further described in detail in combination with the embodiments.

[0023] The utility model discloses an improved travel switch, which optimizes the sealing structure between the touch rod and the switch shell, guarantees the sealing requirement of the travel switch under special use environment such as airborne equipment by the flood seal, and improves the reliability of the travel switch.

[0024] On the basis of the above concept, the travel switch of the utility model is introduced through different embodiments.

[0025] As Figs. 1-3As shown, the travel switch of the embodiment includes a switch housing, a switch body and a touch rod 31, the touch rod 31 is slidably arranged in the touch rod 31 through hole of the switch housing, one end of the touch rod 31 in the switch housing is a trigger end 311, the trigger end 311 cooperates with the switch body, the same as the prior art, the touch rod 31 extends from the front side of the switch housing, and the signal triggering of the travel switch is realized when the touch rod 31 is pressed back by other components; when the outside of the touch rod 31 is removed, the touch rod 31 is reset and extends. A sealing structure is arranged between the touch rod 31 and the inner wall of the touch rod 31 through hole, and the key is that the sealing structure of the travel switch of the utility model includes a flood plug, and the flood plug is located on the outer side of the touch rod 31 through hole. The rear end of the switch housing is connected with a mounting flange 50, so as to fix the whole travel switch.

[0026] Of course, the sealing structure can be only the flood plug, or can further include other sealing layers in addition to the flood plug. For example, an O-shaped sealing ring 49 is arranged on the inner side of the flood plug. The flood plug itself has a relatively reliable sealing protection effect, so as to ensure that foreign matters cannot enter the inside of the switch housing and hinder the movement of the push rod. In cooperation with the O-shaped sealing ring 49, the O-shaped sealing ring 49 serves as a second layer of protection and cooperates with the flood plug 48, so that the air tightness can be better realized, and the use reliability of the O-shaped sealing ring 49 can be prolonged, that is, the reliability in the use process of the product is improved.

[0027] The switch housing is a cylindrical shell 45, the inner cavity of the cylindrical shell 45 is a three-stage stepped inner cavity which is axially through and has a front small diameter section and a rear large diameter section, the switch body is installed in the rear large diameter section, a retaining ring 46 ring groove is arranged at the position close to the rear side of the rear large diameter section, the retaining ring 46 is installed in the retaining ring 46 ring groove and limits the switch body from the rear side, so that the switch body is pressed on the front end step surface of the rear large diameter section. A front section of the touch rod 31 passes through the front small diameter section and extends out of the cylindrical shell 45, so as to be pushed backward by other structures and trigger the switch body. An outer flange 310 arranged on the touch rod 31 is located in the middle diameter section, a reset spring 32 is sleeved on the touch rod 31 rear to the outer flange 310, the rear end of the reset spring 32 abuts against the switch body, and the front end abuts against the outer flange 310, in the natural state, the reset spring 32 sleeved on the touch rod 31 pushes the outer flange 310 from the rear side and presses the outer flange 310 on the step surface on the front side of the middle diameter section.

[0028] The front end surface of the cylindrical shell 45 is provided with a sealing groove which is communicated with the inner hole in the radial direction, the sealing groove is an outward opening groove, the flood plug 48 is installed in the sealing groove, and the front end plate 47 is fixedly installed on the front end surface of the cylindrical shell 45 by screws, so as to keep the flood plug 48 in the sealing groove. The O-shaped sealing ring 49 is installed on the inner wall of the front small diameter section of the cylindrical shell 45.

[0029] The specific structure of the switch body can be a switch body in the prior art, such as the switch body disclosed in the Chinese patent application with the application publication number CN118588476A. In the present embodiment, the structure of the switch body is shown in Fig. 3 The switch body has an inner shell mounting cavity, and a floating short-circuit structure is mounted in the inner shell mounting cavity in the front-rear direction. The floating short-circuit structure is located at the rear side of the lever 31. The floating short-circuit structure includes a short-circuit piece 43 and a retaining spring 430 that provides elastic force to the short-circuit piece 43 towards the side of the lever 31. A pair of wiring terminals are also fixedly mounted in the switch body. The wiring terminals have contact portions located at the front side of the short-circuit piece 43. In the natural state, the retaining spring 430 pushes the short-circuit piece 43 and keeps the short-circuit piece 43 in contact with the contact portions of the two wiring terminals to conduct the two wiring terminals. During the process of the lever 31 moving backward under force, the lever 31 pushes the short-circuit piece 43 away to make it separate from the two wiring terminals, and the two wiring terminals are disconnected to achieve the switching of the travel switch signal.

[0030] The short-circuit piece 43 can be a rigid metal conductor. The short-circuit piece 43 and the two wiring terminals are kept in contact in the abutting state. Then, the short-circuit piece 43 moves a small stroke to achieve separation from the wiring terminals, and the signal switching can be achieved without a large distance, and the size of the travel switch is smaller. Of course, the abutting mode of the short-circuit piece 43 and the contact portions in the front-rear direction naturally achieves the result of the short-circuit piece 43 moving and being disconnected. However, although this can minimize the size of the travel switch, when it is applied in a vibrating environment, the short-circuit piece 43 and the contact portions cannot be in stable contact due to vibration, which is obviously not desirable. Therefore, in order to balance the size and stability, in an embodiment, the contact portion is an elastic terminal 411 that can be elastically deformed in the front-rear direction. The elastic terminal 411 is installed in the switch body, and its rear end is exposed from the front cavity wall of the inner shell mounting cavity. The short-circuit piece 43 is pressed by the retaining spring 430 against the front cavity wall of the inner shell mounting cavity in the natural state, and is in abutment with the rear end of the elastic terminal 411. In this way, in a vibrating environment, the elastic terminal 411 can ensure that the short-circuit piece 43 and the contact portion are in reliable contact, and the travel switch is less likely to have false signals. The elastic terminal 411 can be a snap contact or a spring needle contact, which has good axial elastic deformation capability and can achieve a small size.

[0031] In an embodiment, the pair of wiring terminals are installed in the switch body and are located on the same side of the lever 31. As shown in the embodiment of Fig. 3 The pair of wiring terminals are symmetrically arranged about the lever 31, so that the short-circuit piece 43 can be coaxially arranged with the lever 31 as much as possible. During the process of the lever 31 driving the short-circuit piece 43 to move, the positional relationship between the short-circuit piece 43 and the two wiring terminals is more consistent.

[0032] On the basis of the above-mentioned embodiments, the present application further provides a more optimal embodiment as shown in Fig. 3 As shown in the figure, the terminal further comprises a wiring member extending backward from the contact rod 31, the rear end of the wiring member is a terminal end, and the front end of the wiring member is electrically connected with the front end of the contact part, that is, the entire terminal is a backfolding structure or a U-shaped structure, so that the terminal shares the space in the axial direction with the shorting member 43 and the contact rod 31, and the size of the travel switch in the axial direction is further reduced. Specifically, the entire terminal can comprise a first parallel section, a second parallel section, and a connecting section connecting the front ends of the two parallel sections, the end of the second parallel section is exposed from the front side cavity wall of the inner shell mounting cavity, and the end of the first parallel section is exposed from the rear end of the switch main body for wiring through the radial outer side of the inner shell mounting cavity. Alternatively, in the embodiment as shown in Fig. 3 As shown in the figure, the terminal further comprises a wiring member extending backward from the contact rod 31, the rear end of the wiring member is a terminal end, and the front end of the wiring member is electrically connected with the front end of the contact part, that is, the entire terminal is a backfolding structure or a U-shaped structure, so that the terminal shares the space in the axial direction with the shorting member 43 and the contact rod 31, and the size of the travel switch in the axial direction is further reduced. Specifically, the entire terminal can comprise a first parallel section, a second parallel section, and a connecting section connecting the front ends of the two parallel sections, the end of the second parallel section is exposed from the front side cavity wall of the inner shell mounting cavity, and the end of the first parallel section is exposed from the rear end of the switch main body for wiring through the radial outer side of the inner shell mounting cavity. Alternatively, in the embodiment as shown in

[0033] Based on the above-mentioned embodiments, the switch main body is integrally injection molded, the terminal is cast in the injection molded insulator, the inner shell mounting cavity is formed by injection molding in the insulator, the floating shorting structure is mounted in the inner shell mounting cavity, and the switch main body is provided with a transmission avoiding hole for transmitting the action of the contact rod 31 to the shorting member 43. Alternatively, the switch main body comprises a split inner shell, the split inner shell comprises a cylindrical inner shell 401 with an open front end and a front inner shell 402 blocking the front end of the cylindrical inner shell 401, the floating shorting structure is mounted in the inner shell mounting cavity surrounded by the cylindrical inner shell 401 and the front inner shell 402, the contact part is fixedly mounted in the front inner shell 402 with the rear end exposed to the inner shell mounting cavity, and the front inner shell 402 is provided with a transmission avoiding hole for transmitting the action of the contact rod 31 to the shorting member 43. At this time, the terminal can be integrally injection molded in the front inner shell 402, and the cylindrical inner shell 401 is provided with a through mounting hole corresponding to the terminal at a position corresponding to the terminal, the through mounting hole is for the terminal to pass through from the front to the rear and expose the terminal end. Alternatively, in the embodiment as shown in Fig. 3 As shown in the figure, the terminal further comprises a wiring member extending backward from the contact rod 31, the rear end of the wiring member is a terminal end, and the front end of the wiring member is electrically connected with the front end of the contact part, that is, the entire terminal is a backfolding structure or a U-shaped structure, so that the terminal shares the space in the axial direction with the shorting member 43 and the contact rod 31, and the size of the travel switch in the axial direction is further reduced. Specifically, the entire terminal can comprise a first parallel section, a second parallel section, and a connecting section connecting the front ends of the two parallel sections, the end of the second parallel section is exposed from the front side cavity wall of the inner shell mounting cavity, and the end of the first parallel section is exposed from the rear end of the switch main body for wiring through the radial outer side of the inner shell mounting cavity. Alternatively, in the embodiment as shown in

[0034] On the basis of the above embodiment, the touch rod 31 can be directly connected to the short connecting piece 43, that is, the touch rod 31 drives the short connecting piece 43 to move forward and backward synchronously during the movement of the touch rod 31 forward and backward. Alternatively, in an embodiment, the touch rod 31 is not directly connected to the short connecting piece 43, and there is a certain transmission gap between the touch rod 31 and the short connecting piece 43, that is, the touch rod 31 does not act synchronously with the short connecting piece 43 during the entire movement, but acts synchronously with the short connecting piece 43 during a certain stroke of the movement. In this way, it is also possible to avoid false triggering of the travel switch due to vibration or slight movement of the touch rod 31. As shown in the embodiment of Fig. 3 In the embodiment shown, the short connecting piece 43 is connected with a guide pin 431, the guide pin 431 extends into the transmission avoiding hole and is guided by the transmission avoiding hole, the guide pin 431 is located at the rear side of the touch rod 31 and is isolated from the touch rod 31 in the natural state, and the guide pin 431 has a gap 44 with the triggering end 311 of the touch rod 31, and the touch rod 31 drives the short connecting piece 43 to act by pushing the guide pin 431. By using the structure of the guide pin 431 cooperating with the short connecting piece 43, the linear motion of the short connecting piece 43 can be accurately ensured, and the situation of jamming caused by skewed motion can be prevented, and the reliability of the product during use is further improved. Of course, in another embodiment, the rear end of the touch rod 31 can be in contact with the front end face of the guide pin 431 at all times, and there is no gap 44.

[0035] The short connecting piece 43 is a stepped shaft structure, the end face of the large diameter section is provided with a connecting hole, the rear end of the guide pin 431 extends into the connecting hole and is connected with the short connecting piece 43, the spring 430 is sleeved outside the small diameter section and the front end is pressed at the stepped face, the rear end is pressed against the rear side cavity wall of the inner shell mounting cavity, and the end face of the large diameter section is in contact with the contact part. In this way, other structures are symmetrically arranged around the coaxially arranged structures of the touch rod 31, the guide pin 431 and the short connecting piece 43, and the radial space occupied can be reduced as much as possible.

[0036] The above is only a preferred embodiment of the present application, and does not limit the present application, the patent protection scope of the present application is subject to the claims, and any equivalent structural changes made by referring to the contents of the specification and drawings of the present application should also be included in the protection scope of the present application.

Claims

1. A travel switch comprising a switch housing, a switch body and a lever (31), the lever (31) slidingly passing through a lever (31) through-hole in the switch housing, one end of the lever (31) inside the switch housing being matched with the switch body, and a sealing structure being arranged between the lever (31) and the inner wall of the lever (31) through-hole, characterized in that, The sealing structure comprises a pan seal, which is located on the outer side of the perforation of the contact lever (31). ​ 2. The travel switch of claim 1 wherein, The sealing structure further comprises an O-shaped sealing ring (49) located on the inner side of the pan seal.

3. The travel switch of claim 1 wherein, The switch body comprises a body shell and a floating short-circuit structure installed in the body shell, the floating short-circuit structure comprises a short-circuit piece (43) and a retaining spring (430) providing elastic force to the short-circuit piece (43) towards the side of the contact lever (31), and a pair of wiring terminals are fixedly installed in the body shell, the wiring terminals have contact portions located on the front side of the short-circuit piece (43), the retaining spring (430) pushes the short-circuit piece (43) and keeps the short-circuit piece (43) in abutment with the contact portions of the two wiring terminals to conduct the two wiring terminals in the natural state, in the process of the contact lever (31) moving backward under force, the contact lever (31) pushes back the short-circuit piece (43) to make it separate from the two wiring terminals, and the two wiring terminals are disconnected.

4. The travel switch of claim 3 wherein, The contact portion is an elastic terminal (411) which can be elastically deformed in the front-back direction, the elastic terminal (411) is installed in the body shell, and the rear end thereof is in elastic abutment with the short-circuit piece (43).

5. The travel switch of claim 4 wherein, The elastic terminal (411) is a hair button contact piece or a spring needle.

6. The travel switch according to any one of claims 3 to 5, characterized in that The wiring terminal further comprises a wiring piece extending towards the rear of the contact lever (31), the rear end of the wiring piece is a wiring end, and the front end of the wiring piece is electrically connected with the front end of the contact portion.

7. The travel switch of claim 6 wherein, The wiring piece is an L-shaped contact piece (410), one straight edge of the L-shaped contact piece (410) extends in the front-back direction, and the rear end thereof is the wiring end, and the other straight edge (4101) of the L-shaped contact piece (410) extends towards the contact portion and is in front-back abutment connection with the front end of the contact portion.

8. The travel switch of claim 7 wherein, The body shell is a split inner shell, the split inner shell comprises a cylindrical inner shell (401) with an open front end and a front inner shell (402) sealingly arranged at the front end of the cylindrical inner shell (401), the floating short-circuit structure is installed in an inner shell installation cavity formed by the cylindrical inner shell (401) and the front inner shell (402), the contact portion is fixedly installed in the front inner shell (402) and the rear end thereof is exposed to the inner shell installation cavity, and the front inner shell (402) is provided with a transmission avoiding hole for transmitting the action of the contact lever (31) to the short-circuit piece (43).

9. The travel switch of claim 8 wherein, The front inner shell (402) is provided with a wiring piece installation hole for accommodating the front-back extending straight edge of the L-shaped contact piece (410), the front side of the front shell body is further provided with an installation recess, the other straight edge (4101) of the L-shaped contact piece (410) is located in the installation recess, and the split inner shell further comprises a front blocking plate (403) located at the front end of the front inner shell (402) and used for tightly fixing the L-shaped contact piece (410) in the front shell body.

10. The travel switch of claim 9, wherein, The switch shell comprises a cylindrical outer shell (45), the contact lever (31) is movably installed in the cylindrical outer shell (45), the inner cavity of the cylindrical outer shell (45) has a rear inner step surface, the split inner shell is installed in the inner cavity of the cylindrical outer shell (45) and the front blocking plate (403) is in abutment with the inner step surface, and the inner cavity of the cylindrical outer shell (45) further accommodates a blocking ring (46) for stopping the split inner shell from the rear side.

11. The travel switch of claim 8 wherein, The front side of the short connecting piece (43) is connected with a guide pin (431), which is guided with the transmission avoiding hole, the rear end of the touch rod (31) extends into the transmission avoiding hole and drives the short connecting piece (43) through the guide pin (431).

12. The travel switch of claim 11, wherein, In the natural state, a gap (44) is reserved between the rear end of the touch rod (31) and the guide pin (431).

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