Miniature limit switch

Abstract

The invention discloses a miniature travel switch, comprising a body, a pressing assembly and a circuit switching assembly, wherein the body comprises an upper cylindrical body and a lower cylindrical barrel, the barrel hole of the lower cylindrical barrel is a stepped upper and lower inner cavity hole; the pressing assembly comprises a guide sleeve, a pressing rod I and a pressing rod II, the guide sleeve is slidably matched with the guide hole I of the upper cylindrical body, the pressing rod I is passed through the sleeve hole of the guide sleeve, and the upper part of the pressing rod II is screwed into the lower part of the pressing rod I; the circuit switching assembly comprises a conductive ring, an insulating pressure ring, an insulating seat and a conductor, the guide hole II of the conductive ring is matched with the guide section of the pressing rod II, a compression spring II is pressed between the conductive ring and the pressing rod I, the insulating pressure ring is matched with the upper part of the lower inner cavity hole, the insulating seat is arranged at the bottom of the insulating pressure ring at the lower part of the lower inner cavity hole, left and right symmetrical conductors are passed through the insulating seat, the upper ends of the left and right conductors are externally pressed between the insulating seat and the insulating pressure ring, and the upper ends are internally aligned with the conductive ring, and a compression spring I is pressed between the insulating pressure ring and the guide sleeve.

Description

Technical Field

[0001] The invention relates to a component for connecting and disconnecting a circuit, in particular to a miniature travel switch. Background Art

[0002] Miniature limit switches are used in electrical control systems in special industries to realize the circuit on and off functions of the control system. They are key components of special electrical control systems. In recent years, with the rapid development of science and technology in my country, the requirements for various technical indicators of component development have become increasingly higher, and the requirements for weight and volume have become increasingly smaller.

[0003] Due to the unique characteristics of miniature limit switches, they are widely used in many electrical control devices. Miniature limit switches are required to be able to operate normally in harsh natural environments such as humidity, high and low temperatures (-65℃ to 125℃), sand, dust, rain, mold and salt spray, as well as in mechanical environments with severe centrifugal, vibration and impact.

[0004] This type of limit switch uses a high-strength structural design with external seals and snap-on contacts, resulting in a long lifespan of 25,000 cycles. Therefore, the reliability of the seal structure and contact on / off switching mechanism of the miniature limit switch is crucial to its proper operation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a miniature travel switch which can reliably realize the circuit on and off functions.

[0006] The miniature limit switch capable of solving the above-mentioned technical problems comprises a body, a pressing component and a circuit switching component arranged based on the body. The difference is that:

[0007] 1. The body includes a coaxial upper cylinder and a lower cylinder. A coaxial guide hole I is opened in the upper cylinder. The barrel hole of the lower cylinder is a stepped coaxial upper inner cavity hole (small) and a lower inner cavity hole (large). The upper inner cavity hole is connected to the guide hole I.

[0008] 2. The pressing assembly includes a guide sleeve, a pressing rod I and a pressing rod II. The guide sleeve is slidably fitted with the guide hole I and its lower end is located at the top of the upper inner cavity hole. The pressing rod I is inserted into the sleeve hole of the guide sleeve and its lower end is at the bottom of the guide sleeve. The top of the pressing rod I is screwed with a button that is pressed against the top of the guide sleeve, and the upper part of the pressing rod II is screwed into the bottom of the pressing rod I.

[0009] 3. The circuit switching assembly includes a conductive ring, an insulating pressure ring, an insulating seat and a conductor. The conductive ring is matched with the guide section at the lower part of the pressing rod II through the guide hole II at the top and is limited downwardly to the lower part of the pressing rod II. A compression spring II is pressed on the pressing rod II between the conductive ring and the pressing rod I. The insulating pressure ring is matched with the upper part of the lower inner cavity hole and is limited upwardly to the upper inner cavity hole. The insulating seat is arranged at the lower part of the lower inner cavity hole at the bottom of the insulating pressure ring and is axially limited downwardly by the circumferential edge of the lower wall of the lower cylindrical tube. The left and right symmetrical conductors are passed through the insulating seat. The outer upper ends of the left and right conductors are pressed tightly between the insulating seat and the insulating pressure ring. The inner upper ends of the left and right conductors are aligned with the conductive ring. A compression spring I is pressed in the upper inner cavity hole between the insulating pressure ring and the guide sleeve.

[0010] In order to facilitate the installation of the switch, an external thread is provided on the outer circumference of the upper cylinder, and a coaxial annular groove is provided on the top of the lower cylindrical tube at the bottom of the external thread, and a sealing ring is provided in the annular groove.

[0011] The installation method of the switch is as follows: the upper cylinder passes upward through the installation hole of the base plate, and the locking nut is screwed into the external thread of the upper cylinder to fix the lower cylinder on the base plate.

[0012] In the off state, the compression spring I returns the guide sleeve, pressing rod I and pressing rod II upward, and the compression spring II returns the conductive ring downward. The distance between the bottom of the pressing rod and the upper ends of the left and right conductors is the full pressing stroke S of the button, the distance between the bottom of the conductive ring and the upper ends of the left and right conductors is the connection stroke S1 of the button pressing, and the distance between the bottom of the pressing rod II and the bottom of the conductive ring is the connection overstroke S2 ​​of the button pressing.

[0013] Beneficial effects of the present invention:

[0014] 1. In the structure of the miniature limit switch of the present invention, the button is pressed smoothly without any sticking or straining, and the conductive ring can smoothly connect the left and right conductors to realize the conduction function of the circuit, which is suitable for special control equipment and civil electrical control systems.

[0015] 2. In the structure of the present invention, the conductive ring is in stable contact with the left and right conductors, and is safe and reliable when separated, and is not affected by harsh natural environments and severe mechanical environments.

[0016] 3. The present invention has a compact structure, small size, light weight, good sealing performance, can shield electromagnetic interference, and has good versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of an installation embodiment of the present invention.

[0018] Figure 2 for Figure 1Schematic diagram of the internal structure of an embodiment, showing the switch in the off state.

[0019] Figure 3 for Figure 1 Schematic diagram of the internal structure of an embodiment, showing the switch in the on state.

[0020] Figure 4 for Figure 1 Schematic diagram of the internal structure of the body in an embodiment.

[0021] Figure 5 for Figure 1 Schematic diagram of the structure of the local pressing component and the local circuit switching component in the embodiment.

[0022] Figure 6(a) shows Figure 1 Schematic diagram of the structure of the local circuit switching assembly in an embodiment (AA cross-sectional view in Figure 6(b)).

[0023] FIG6( b ) is a top view of FIG6( a ).

[0024] Figure number identification: 1. Machine body; 1-1. Upper cylinder; 1-2. Lower cylinder; 2. Guide hole I; 3. Guide sleeve; 4. Press rod I; 5. Upper inner cavity hole; 6. Lower inner cavity hole; 7. Press rod II; 8. Conductive ring; 9. Insulating pressure ring; 10. Insulating seat; 11. Conductor; 12. Compression spring II; 13. Compression spring I; 14. Button; 15. Locking nut; 16. Annular groove; 17. Sealing ring; 18. Base plate; 19. Gasket. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0026] The miniature limit switch of the present invention comprises a body 1 mounted on a substrate 18 and a pressing component and a circuit opening and closing component arranged based on the body 1. Figure 1 shown.

[0027] The body 1 includes a coaxial small-diameter upper cylinder 1-1 and a large-diameter lower cylinder 1-2, a coaxial guide hole Ⅰ2 is provided in the upper cylinder 1-1, and the stepped cylinder hole of the lower cylinder 1-2 includes a coaxial upper inner cavity hole 5 and a lower inner cavity hole 6. The inner diameter of the upper inner cavity hole 5 is smaller than the inner diameter of the lower inner cavity hole 6. The guide hole Ⅰ2 is connected to the upper inner cavity hole 5. An external thread is provided on the outer circumferential surface of the upper cylinder 1-1, and an annular groove 16 is provided on the top of the lower cylinder 1-2 at the bottom of the external thread. A sealing ring 17 is provided in the annular groove 16. Figure 4 shown.

[0028] The pressing assembly includes a guide sleeve 3, a pressing rod I4 and a pressing rod II7. The guide sleeve 3 is slidably fitted in the guide hole I2 of the upper cylinder 1-1. The ring body with an increased diameter at the lower end of the guide sleeve 3 is arranged in the upper inner cavity hole 5 of the lower cylindrical tube 1-2. The pressing rod I4 is fitted in the sleeve hole of the guide sleeve 3. The shaft body with an increased diameter at the lower end of the pressing rod I4 is at the bottom of the guide sleeve 3. The top and bottom of the pressing rod I4 are both provided with coaxial threaded holes. The upper threaded hole of the pressing rod I4 is screwed with a button 14 that is pressed tightly on the top of the guide sleeve 3. The pressing rod II7 includes an upper external threaded section, a lower guide section and a shaft body with an increased diameter at the lower end. The upper external threaded section of the pressing rod II7 is screwed into the bottom threaded hole of the pressing rod I4. The threaded screwing part of the two is provided with an insulator to block the conduction between the pressing rod II7 and the pressing rod I4. Figure 2 、 Figure 3 shown.

[0029] The circuit switch assembly includes a conductive ring 8, an insulating pressure ring 9, an insulating seat 10 and a conductor 11. A guide hole II is provided on the top of the conductive ring 8. The conductive ring 8 slides with the guide section of the pressing rod II through the guide hole II and is located at the lower end of the pressing rod II7 to the lower limit. A compression spring II12 is installed on the guide section of the pressing rod II7 between the conductive ring 8 and the bottom of the pressing rod I4; the insulating pressure ring 9 is fitted into the lower inner cavity hole 6 of the lower cylindrical tube 1-2, and the top of the insulating pressure ring 9 is limited to the bottom of the upper inner cavity hole 5; a coaxial countersunk hole is provided on the top of the insulating seat 10, and a square hole that is symmetrical on the left and right and passes through the insulating seat 10 is provided on the countersunk hole. The insulating seat 10 is fitted into the lower inner cavity hole 6 at the bottom of the insulating pressure ring 9, and the lower part of the insulating seat 10 is closed by the wall of the bottom of the lower cylindrical tube 1-2. Axial limit; the conductor 11 is a T-shaped contact piece that is symmetrical on the left and right. The upper semicircular body of the left contact piece is in the left semicircular hole of the top countersunk hole of the insulating seat 10 and its left half is pressed by the insulating pressure ring 9. The lower end wiring portion of the left contact piece passes through the left square hole and extends vertically downward from the insulating seat 10. The upper semicircular body of the right contact piece is in the right semicircular hole of the top countersunk hole of the insulating seat 10 and its right half is pressed by the insulating pressure ring 9. The lower end wiring portion of the right contact piece passes through the right square hole and extends vertically downward from the insulating seat 10; a press-fitted compression spring Ⅰ13 is provided in the upper inner cavity hole 5 between the bottom of the guide sleeve 3 and the top of the insulating pressure ring 9, and a gasket 19 is provided at the contact position between the lower end of the compression spring Ⅰ13 and the insulating pressure ring 9. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 , as shown in Figure 6(a) and Figure 6(b).

[0030] Figure 2The figure shows the on-off state of the switch, at which time the compression spring I13 and the compression spring II12 are in a free state of press-fitting, the guide sleeve 3 is reset upward and axially limited by the top of the upper inner cavity hole 5, the button 14 is pushed upward and stays in a high position to be pressed, the conductive ring 8 is reset downward and limited at the lower end of the pressing rod II7, the lower end of the conductive ring 8 is at the ring mouth of the insulating pressure ring 9, and downward corresponds to the right semicircular body of the left contact piece and the left semicircular body of the right contact piece; the distance between the bottom of the pressing rod II7 and the top of the left and right contact pieces is the full pressing stroke S of the button 14, the distance between the bottom of the conductive ring 8 and the top of the left and right contact pieces is the connection stroke S1 (the switch circuit is turned on) pressed by the button 14, and the distance between the bottom of the pressing rod II7 and the bottom of the conductive ring 8 is the connection overstroke S2 ​​(the switch circuit continues to be turned on) pressed by the button 14.

[0031] Figure 3 The figure shows the on state of the switch. In the on-stroke section S1 (1.7 mm) when the button 14 is pressed, the compression spring I13 is compressed, the descending conductive ring 8 enters the ring hole of the insulating pressure ring 9 and presses on the left and right conductors 11 to turn on the circuit. In the on-stroke section S2 (1.3 mm) when the button 14 is continued to be pressed, the compression spring II12 is compressed, the conductive ring 8 continues to press on the left and right conductors 11 to turn on the circuit, and the bottom of the pressing rod II7 is pressed down on the left and right conductors 11 to stop.

[0032] When the button 14 is released, it returns to its original position, and the conductive ring 8 is separated from the left and right conductors 11, thereby disconnecting the circuit.

[0033] The body 1 is mounted on the base plate 18 in the following manner:

[0034] The upper cylinder 1-1 passes upward through the corresponding mounting hole on the base plate 18, and at least one locking nut 15 is screwed into the external thread of the upper cylinder 1-1 to fix the lower cylinder 1-2 to the bottom of the base plate 18. The sealing ring 17 seals the gap between the base plate 18 and the lower cylinder 1-2. Figure 1 、 Figure 2 、 Figure 3 shown.

[0035] The microstructure of the present invention is compact and can be made very small. For example, a product of one model specification has an outer dimension of 21.6 mm×φ7 mm and weighs only 2 g.

Claims

1. A miniature travel switch, comprising a body (1) and a pressing component and a circuit opening and closing component arranged based on the body (1), characterized in that: The body (1) comprises a coaxial upper cylinder (1-1) and a lower cylindrical barrel (1-2); a coaxial guide hole I (2) is provided in the upper cylindrical barrel (1-1); the barrel hole of the lower cylindrical barrel (1-2) is a stepped coaxial upper inner cavity hole (5) and a lower inner cavity hole (6); the upper inner cavity hole (5) is communicated with the guide hole I (2); The pressing assembly includes a guide sleeve (3), a pressing rod I (4) and a pressing rod II (7), wherein the guide sleeve (3) is slidably matched with the guide hole I (2) and its lower end is located at the top of the upper inner cavity hole (5) toward the upper limit, the pressing rod I (4) is inserted into the sleeve hole of the guide sleeve (3) and its lower end is located at the bottom of the guide sleeve (3), the top of the pressing rod I (4) is screwed with a button (14) pressed against the top of the guide sleeve (3), and the upper part of the pressing rod II (7) is screwed with the lower part of the pressing rod I (4); The circuit switch assembly includes a conductive ring (8), an insulating pressure ring (9), an insulating seat (10) and a conductor (11). The conductive ring (8) is matched with the guide section at the lower part of the pressing rod II (7) through the guide hole II at the top and is located at the bottom of the pressing rod II (7) to the lower limit. A compression spring II (12) is installed on the pressing rod II (7) between the conductive ring (8) and the pressing rod I (4). The insulating pressure ring (9) is matched with the upper part of the lower inner cavity hole (6) and is located at the upper inner cavity hole (5) to the upper limit. The insulating seat (10) is located at the bottom of the insulating pressure ring (9) at the lower part of the lower inner cavity hole (6) and is axially limited downward by the circumferential edge of the lower wall of the lower cylindrical tube (1-2). The left and right symmetrical conductors (11) are passed through the insulating seat (10). The upper ends of the left and right conductors are pressed tightly between the insulating seat (10) and the insulating pressure ring (9). The upper ends of the left and right conductors are aligned with the conductive ring (8). A compression spring I (13) is installed in the upper inner cavity hole (5) between the insulating pressure ring (9) and the guide sleeve (3).

2. The miniature travel switch according to claim 1, characterized in that: An external thread is provided on the outer circumference of the upper cylinder (1-1), a coaxial annular groove (16) is provided on the top of the lower cylindrical tube (1-2) at the bottom of the external thread, and a sealing ring (17) is provided in the annular groove (16).

3. The miniature travel switch according to claim 2, characterized in that: The upper cylinder (1-1) passes upward through the mounting hole of the base plate (18), and the locking nut (15) is screwed onto the external thread of the upper cylinder (1-1) to fix the lower cylinder (1-2) on the base plate (18).

4. The miniature travel switch according to any one of claims 1 to 3, characterized in that: In the disconnected state, the compression spring I (13) returns the guide sleeve (3), the pressing rod I (4) and the pressing rod II (7) upward, and the compression spring II (12) returns the conductive ring (8) downward. The distance between the bottom of the pressing rod II (7) and the upper ends of the left and right conductors is the full pressing stroke S of the button (14), the distance between the bottom of the conductive ring (8) and the upper ends of the left and right conductors is the connection stroke S1 of the button (14), and the distance between the bottom of the pressing rod II (7) and the bottom of the conductive ring (8) is the connection overstroke S2 ​​of the button (14).

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