Optical fiber passive limit switch

Abstract

The utility model relates to an optical fiber passive limit switch, which comprises a shell, an optical switch arranged in the shell and a push rod sliding towards a trigger rod of the optical switch, the shell is coupled with a torsion shaft driving the push rod to slide, and the torsion shaft is fixedly connected with a swing rod extending to a motion path of a moving part. According to the scheme, during use, the shell is placed at a proper position, the swing rod is located on the movement path of the moving part, when the limiting position of the moving part needs to be monitored, the swing rod is located at the position close to the limiting position, and when the moving part reaches the limiting position, the swing rod can be driven to rotate around the axis of the torsion shaft, and meanwhile the torsion shaft is driven to rotate; the torsion shaft rotates to drive the push rod to slide, so that the push rod abuts against a trigger rod of the optical switch to trigger the optical switch and cut off an optical signal, and the swing rod, the torsion shaft and the push rod are utilized to trigger the optical switch and transmit the signal through an optical fiber, so that the influence of electromagnetic interference is reduced, and the accuracy of monitoring the limit position of the moving part is ensured.

Description

Technical Field

[0001] The utility model relates to the field of switches, in particular to the technical field of limit switches, and specifically refers to an optical fiber passive limit switch. Background Art

[0002] Limit switch is a commonly used low-current main control electrical appliance, which uses the collision of the moving parts of the production machinery to make its contacts move to connect or disconnect the control circuit to achieve a certain control purpose. Usually, this type of switch is used to limit the position or stroke of mechanical movement, so that the moving machinery can automatically stop, reverse, change speed or automatically reciprocate at a certain position or stroke.

[0003] However, most existing limit switches are controlled by electrical signals. In the long-distance fixed-point positioning state, the electrical signals will be greatly affected by electromagnetic interference during operation, and there are problems such as unstable signals and over-reliance on electricity. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides an optical fiber passive limit switch, which utilizes a swing rod, a torsion shaft, and a push rod to trigger an optical switch and uses optical fiber to transmit signals, thereby reducing the influence of electromagnetic interference and ensuring the accuracy of monitoring the extreme position of a moving part.

[0005] The utility model is realized through the following technical scheme: a fiber optic passive limit switch, comprising a housing, an optical switch located in the housing, and a push rod sliding toward a trigger rod of the optical switch; a torsion shaft driving the push rod to slide is axially connected to the housing, and a swing rod extending to the motion path of the moving part is fixedly connected to the torsion shaft.

[0006] When the present solution is in use, the housing is placed in a suitable position, and the swing arm is located on the moving path of the moving part. When the moving part needs to be monitored at its extreme position, the swing arm is located close to the extreme position. When the moving part reaches the extreme position, the swing arm is driven to rotate around the axis of the torsion shaft, and the torsion shaft is driven to rotate at the same time. The rotation of the torsion shaft drives the push rod to slide, so that the push rod is pushed onto the trigger rod of the optical switch, thereby triggering the optical switch and cutting off the optical signal. The optical switch is triggered by the swing arm, torsion shaft and push rod, and the signal is transmitted using optical fiber, thereby reducing the influence of electromagnetic interference and ensuring the accuracy of monitoring the extreme position of the moving part.

[0007] Preferably, the torsion shaft is detachably connected with a sleeve sleeved outside the torsion shaft. This preferred solution protects the torsion shaft through the setting of the sleeve.

[0008] Preferably, an operating block is fixed to the top surface of the shell, the torsion shaft is axially connected to the operating block, and the torsion shaft is also sleeved with a torsion spring located on both sides of the sleeve, one end of the torsion spring is connected to the sleeve, and the other end is connected to the operating block.

[0009] This preferred solution uses a torsion spring to drive the torsion shaft and the swing rod to reset.

[0010] Preferably, the shell is provided with a sliding hole for the push rod to slide, a convex ring is provided in the sliding hole, the push rod is provided with a limiting ring located above the convex ring, the push rod is sleeved with a spring located between the limiting ring and the convex ring, and the top end of the push rod is pushed onto the torsion shaft.

[0011] The preferred solution provides a guide function to the push rod by setting the sliding hole. Meanwhile, the setting of the spring facilitates the push rod to be pushed onto the sleeve, so that the rotation of the sleeve can drive the slide of the push rod.

[0012] Preferably, a plane extending along the axial direction of the sleeve is processed on the circumferential surface thereof, and the spring pushes the push rod to the plane.

[0013] When this preferred solution is in use, when the torsion shaft has not rotated, the push rod is pushed onto the plane. When the torsion shaft rotates, the push rod is pushed onto the circumferential surface of the sleeve along the plane. At the connection between the plane and the circumferential surface of the sleeve, the circumferential surface of the sleeve pushes the push rod to move downward.

[0014] Preferably, one end of the swing lever away from the torsion axis is hinged with a roller that cooperates with the moving part.

[0015] This preferred solution reduces the friction between the roller and the moving part by setting the roller.

[0016] The beneficial effects of the utility model are as follows: the shell is placed in a suitable position, and the swing arm is located on the moving path of the moving part. When the limit position of the moving part needs to be monitored, the swing arm is located near the limit position. When the moving part reaches the limit position, the swing arm will be driven to rotate around the axis of the torsion shaft, and the torsion shaft will be driven to rotate at the same time. The rotation of the torsion shaft will drive the push rod to slide, so that the push rod is pushed onto the trigger rod of the optical switch, thereby triggering the optical switch and cutting off the optical signal. The swing arm, the torsion shaft and the push rod are used to trigger the optical switch, and the optical fiber is used to transmit the signal, thereby reducing the influence of electromagnetic interference, thereby ensuring the accuracy of the monitoring of the limit position of the moving part; through the use of the torsion spring, the torsion shaft and the swing arm are driven to reset; through the setting of the sliding hole, the push rod is given a guiding effect. At the same time, the setting of the spring makes it easy for the push rod to be pushed onto the sleeve, so that the rotation of the sleeve can drive the sliding of the push rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a side view schematic diagram of the structure of the utility model;

[0018] Figure 2 This is a schematic diagram of the main structure of the utility model;

[0019] Figure 3It is the three-view drawing of the casing;

[0020] Figure 4 It is the state diagram of the structure and use of the utility model;

[0021] As shown in the figure:

[0022] 1. Housing, 2. Optical switch, 3. Push rod, 4. Spring, 5. Torsion spring, 6. Torsion shaft, 7. Sleeve, 8. Operating block, 9. Roller, 10. Swing rod, 11. Circlip, 12. Sealing ring, 13. Moving parts. DETAILED DESCRIPTION

[0023] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0024] Refer to the attached Figure 1-4 The utility model discloses a fiber optic passive limit switch, comprising a housing 1 and an operating block 8 located on the top surface of the housing 1, wherein a cavity is formed in the operating block 8.

[0025] An optical switch 2 is arranged in the shell 1, and a trigger rod of the optical switch 2 extends upward. A sliding hole extending upward into the cavity is provided just above the trigger rod, that is, a sliding hole penetrating the top wall of the shell 1 is provided on the shell 1, and a push rod 3 sliding along the height direction is slidably connected in the sliding hole, and a convex ring is provided in the sliding hole, and the outer diameter of the push rod 3 is adapted to the inner diameter of the convex ring. A limiting ring located above the convex ring is provided on the push rod 3, and a spring 4 located between the limiting ring and the convex ring is sleeved on the push rod 3, and the spring 4 drives the push rod 3 to move upward.

[0026] The operating block 8 is internally connected to a torsion shaft 6 located in the cavity, and the torsion shaft 6 is connected to a sleeve 7 sleeved on the outside of the torsion shaft 6 through screws. The sleeve 7 is sleeved with two torsion springs 5 ​​located on both sides of the push rod 3, one end of the torsion spring 5 is fixedly connected to the sleeve 7, and the other end is fixedly connected to the operating block 8.

[0027] A plane extending along the axial direction is processed on the circumferential surface of the sleeve 7, and the spring 4 pushes the push rod 3 to the plane, and the torsion shaft 6 extends along its axial direction to the outside of the operating block 8. The operating block 8 is provided with a positioning hole for the torsion shaft 6 to pass through, and a sealing ring 12 sleeved on the torsion shaft 6 is provided in the positioning hole. The part of the torsion shaft 6 located outside the operating block 8 is fixedly connected to a swing rod 10 extending upward, and an elastic retaining ring 11 is also provided on the torsion shaft 6 to limit its axial movement. The end of the swing rod 10 away from the torsion shaft 6 is hinged with a roller 9 that cooperates with the moving part 13.

[0028] In particular, in this solution, the optical switch 2 uses optical fiber transmission, the signal has no drift, no need for correction, high transmission rate and no need for power supply, which reduces electromagnetic interference problems;

[0029] All the optical fiber interfaces in this solution are quick-connect, eliminating the need for optical fiber splicing and making on-site installation and replacement easy.

[0030] When the utility model is in use, the two optical fiber passive limit switches are arranged along the moving direction of the moving part 13, and the moving part 13 is located between the two optical fiber passive limit switches, and the optical fiber passive limit switch is located at the extreme position of the moving part 13;

[0031] When the moving part 13 approaches the limit position, it touches the roller 9, and then drives the swing rod 10, the torsion shaft 6, and the sleeve 7 to rotate around the axis of the torsion shaft 6. The rotation of the sleeve 7 makes the circumferential surface of the sleeve 7 press against the push rod 3, thereby driving the push rod 3 to move downward. At this time, the torsion spring 5 and the spring 4 are elastically deformed, and the push rod 3 moves downward to push the trigger rod of the optical switch 2, thereby cutting off the optical signal.

[0032] The system electrically connected to the optical switch 2 receives the command and controls the moving part 13 to stop moving. The moving part 13 is at the limit position. When the moving part 13 to be measured moves in the opposite direction, the torsion spring 5 drives the sleeve 7 to rotate, and then drives the torsion shaft 6 and the swing rod 10 to gradually return to their original positions. At the same time, as the sleeve 7 rotates, the push rod 3 moves upward under the action of the spring 4, and the trigger rod of the optical switch 2 gradually returns to its original position, and the optical signal is turned on.

[0033] Of course, the above description is not limited to the above examples. The technical features not described in the present invention can be achieved by or by adopting the existing technology, which will not be repeated here. The above embodiments and drawings are only used to illustrate the technical scheme of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that the changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not deviate from the purpose of the present invention and should also fall within the scope of protection of the claims of the present invention.

Claims

1. A fiber optic passive limit switch, characterized in that: The invention comprises a housing (1), an optical switch (2) located in the housing (1), and a push rod (3) that slides toward a trigger rod of the optical switch (2); the housing (1) is axially connected to a torsion shaft (6) that drives the push rod (3) to slide; and the torsion shaft (6) is fixedly connected to a swing rod (10) that extends to the moving path of a moving part (13).

2. The optical fiber passive limit switch according to claim 1, characterized in that: The torsion shaft (6) is detachably connected to a sleeve (7) sleeved on the outside of the torsion shaft (6).

3. The optical fiber passive limit switch according to claim 2, characterized in that: An operating block (8) is fixedly connected to the top surface of the housing (1), the torsion shaft (6) is axially connected to the operating block (8), and a torsion spring (5) is sleeved on the torsion shaft (6) and located on both sides of the sleeve (7), one end of the torsion spring (5) is connected to the sleeve (7), and the other end is connected to the operating block (8).

4. The optical fiber passive limit switch according to claim 3, characterized in that: The housing (1) is provided with a sliding hole for the push rod (3) to slide, a convex ring is provided in the sliding hole, the push rod (3) is provided with a limit ring located above the convex ring, the push rod (3) is sleeved with a spring (4) located between the limit ring and the convex ring, and the top end of the push rod (3) is pressed against the sleeve (7).

5. The optical fiber passive limit switch according to claim 4, characterized in that: A plane extending along the axial direction is machined on the circumferential surface of the sleeve (7), and the spring (4) pushes the push rod (3) onto the plane.

6. The optical fiber passive limit switch according to claim 1, characterized in that: One end of the swing rod (10) away from the torsion shaft (6) is hingedly connected to a roller (9) that cooperates with the moving part (13).

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