Groove-shaped Hall inductive switch

Abstract

The utility model discloses a groove-shaped Hall inductive switch. The groove-shaped Hall inductive switch comprises a shell, a permanent magnet and a Hall switch element, wherein a groove is formed in the middle of the shell. And the permanent magnet and the Hall switch element are respectively arranged in the cavities on the two sides of the notch on the shell. When there is no ferromagnetic shielding object in the notch, the magnetic line of force of the permanent magnet penetrates through the shell and enables the Hall switch element to generate an induction signal, and when there is a ferromagnetic shielding object entering the notch, the magnetic line of force of the permanent magnet is blocked, so that the Hall switch element does not sense a magnetic field any more. According to the scheme, original optical signals are replaced by magnetic field signals, so that the defect that a photoelectric switch cannot be applied to a high-dust environment is overcome.

Description

Technical Field

[0001] The utility model relates to a position induction switch, in particular to a groove-shaped induction switch based on the Hall effect. Background Art

[0002] Groove switches are usually used to detect whether there is a sheet-shaped obstacle in the middle. When the obstacle enters or leaves, the switch will show the characteristics of conduction or disconnection. Groove switches have the characteristic of high detection position accuracy compared with other types of proximity switches (such as reflective photoelectric switches, capacitive and inductive proximity switches). However, the existing groove switches are all based on the photoelectric principle, that is, the common groove-shaped photoelectric switches on the market. But due to the photoelectric principle and the open structure, the groove-shaped photoelectric switches cannot be applied to the use scenarios with a lot of dust. When there is a lot of dust inside the sensor, it may block the light path, resulting in the failure of the photoelectric switch. And the traditional proximity switches have the disadvantages of low detection accuracy and high cost.

[0003] Traditional Hall induction switches can only be used to detect magnetic objects. For example, a small magnet is set at the corresponding position. When the magnet approaches the Hall switch, the Hall switch gives a corresponding signal. However, the Hall switch cannot detect non-magnetic objects. Since the cost of processing magnetic materials into a specified shape is relatively high, in the case of a non-uniform distribution of detection points, the common practice is to embed permanent magnets at the corresponding positions in the parts to be detected to achieve the purpose of detection. This scheme is greatly affected by the sensitivity difference of the Hall element and the magnetic field strength of the permanent magnet, so the detection accuracy is relatively low. At the same time, the process of fixing the permanent magnet also increases the assembly difficulty of the product.

[0004] From the above analysis, it can be seen that there is a lack of a position induction switch with high precision, low cost and not affected by dust in the prior art. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the utility model provides a groove-shaped Hall induction switch. The Hall induction switch is composed of a housing with a groove in the middle, a permanent magnet and a Hall switch element. The structure is similar to that of the traditional groove-shaped photoelectric switch, but the difference is that the Hall switch scheme proposed in this application uses a magnetic field to replace the original optical signal, thus avoiding the defect that the photoelectric switch cannot be applied to the high-dust environment.

[0006] To achieve the above object, the technical solution adopted by the utility model is as follows:

[0007] A grooved Hall induction switch includes a housing, a permanent magnet, and a Hall switch element; the housing is made of a non-magnetic material, a grooved opening is provided at the front end of the housing, and a cavity is provided on each side of the grooved opening; the two cavities are respectively used to place the permanent magnet and the Hall switch element. The Hall switch element can at least sense one of the N-pole magnetic field and the S-pole magnetic field, and the magnetic pole in the permanent magnet that can induce the Hall switch element faces the Hall switch element. When both magnetic poles can induce the Hall switch element, one of the magnetic poles faces the Hall switch element.

[0008] Preferably, the width of the grooved opening is 3 mm to 8 mm.

[0009] Preferably, the width of the grooved opening is 4 mm.

[0010] Preferably, the permanent magnet is a cylinder with a diameter of 2 mm to 4 mm and a height of 1 mm to 3 mm, and the magnetization direction is axial magnetization.

[0011] Preferably, the permanent magnet is a cylinder with a diameter of 3 mm and a height of 2 mm.

[0012] Preferably, the permanent magnet is made of neodymium iron boron material.

[0013] Preferably, the Hall switch element is a unipolar Hall effect switch or an all-pole Hall effect switch.

[0014] Preferably, the housing is made of plastic.

[0015] Preferably, the housing is made of translucent plastic.

[0016] Preferably, an indicator light is provided in the housing, and the indicator light is a light-emitting diode.

[0017] Compared with the prior art, a grooved Hall induction switch proposed by the present application uses a grooved housing to fix the permanent magnet and the Hall switch element on both sides of the groove opening. When there is no ferromagnetic shielding object in the groove opening, the magnetic force lines of the permanent magnet will penetrate the housing and induce a signal in the Hall switch element. When a ferromagnetic shielding object enters the groove opening, the magnetic force lines of the permanent magnet are blocked, and the Hall switch element can no longer sense the magnetic field. This solution uses a magnetic field instead of the original optical signal, avoiding the defect that the photoelectric switch cannot be applied to high-dust environments. At the same time, only when a ferromagnetic shielding sheet appears between the permanent magnet and the Hall switch element, the magnetic force lines will be blocked. Therefore, the detection accuracy is also higher than that of the traditional open-type Hall detection scheme. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the appearance of a grooved Hall induction switch of the present utility model.

[0019] Figure 2 The utility model is a schematic diagram of the internal structure of a slot-shaped Hall induction switch.

[0020] Figure 3 The utility model is a structural schematic diagram of a slot-shaped Hall induction switch when an obstruction is inserted. DETAILED DESCRIPTION

[0021] Below, in conjunction with the accompanying drawings and specific implementation methods, a cam structure of a strapping machine movement of the present invention is further described to facilitate a clearer understanding of the technical idea claimed for protection of the present invention.

[0022] Figure 1 1 is a schematic diagram of the appearance of this embodiment, from which it can be seen that a slot-shaped opening 12 is provided on the housing 11. The width of the slot-shaped opening is 4 mm.

[0023] Figure 2 The figure is a schematic diagram of the internal structure of the present embodiment after being cut open. The housing 11 is provided with cavities on both sides of the slot-shaped opening 12. A permanent magnet 22 is placed in the upper cavity, and a circuit board 23 is placed in the lower cavity. A Hall switch element 231 is provided on the front end of the circuit board 23, and the Hall switch element 231 is provided directly below the permanent magnet 22; at the same time, an indicator light 232 is also provided on the circuit board 23. The indicator light 232 is a light-emitting diode, and the housing 11 is made of translucent plastic material, so that the state of the internal indicator light 232 can be observed without providing an opening on the housing or adding a light guide column.

[0024] The permanent magnet 22 is a cylinder with a diameter of 3 mm and a height of 2 mm. The material of the permanent magnet is neodymium iron boron, and the magnetization direction is axial magnetization, that is, the NS poles are on the upper and lower planes of the cylindrical permanent magnet 22.

[0025] In this embodiment, there are two options for selecting the Hall switch element 231. One is to use a unipolar Hall effect switch (a Hall effect switch that only responds to a magnetic field of a single polarity); the other is to use an omnipolar Hall effect switch (a Hall effect switch that responds to any magnetic field).

[0026] The first scheme of this embodiment uses an N-pole Hall effect switch, and the N pole of the permanent magnet 22 faces the Hall switch element 231; the second scheme uses an omnipolar Hall effect switch, and any pole of the permanent magnet 22 facing the Hall effect switch 231 can trigger the Hall effect switch. If the first scheme is changed to use an S-pole Hall effect switch, the S pole of the permanent magnet 22 faces the Hall switch element 231, and the relevant effect can also be achieved. Whether the first scheme or the second scheme is used, the working reasons are exactly the same, and they are explained here uniformly.

[0027] In this embodiment, for a unipolar Hall effect switch, it will be in the conducting state when a magnetic field with the corresponding polarity passes through it, otherwise it will be in the off state; for an all-polarity Hall switch, it will be in the conducting state when a magnetic field with any polarity passes through it, otherwise it will be in the off state. If necessary, a Hall effect switch with an inverted output logic can also be used here.

[0028] As Figure 2 shown, when there is no ferromagnetic shielding object in the middle of the Hall induction switch, the magnetic lines of force of the permanent magnet 22 will penetrate the Hall switch element 231 below, and the Hall switch element 231 conducts. As Figure 3 shown, when there is a ferromagnetic shielding object 31 in the middle of the Hall induction switch, the magnetic lines of force emitted by the permanent magnet 22 are deflected by the shielding object 31 and cannot penetrate the Hall switch element 231. At this time, the Hall switch element is in the off state. Because only when the shielding piece 31 is in the middle of the connection line between the permanent magnet 22 and the Hall switch element 231 will the magnetic lines of force between the two be cut off, and the magnetic field strength of the permanent magnet 22 and the distance between the two have a limited impact on it. Therefore, the position detection accuracy of this solution is relatively high.

[0029] From the description of the above embodiments, it can be seen that the solution described in this application is similar to the slot-type photoelectric switch in the prior art. The difference is that the photoelectric emission tube in the photoelectric switch is replaced with a permanent magnet, and the photoelectric receiving tube is replaced with a Hall effect switch. Since the magnetic field will only be shielded by ferromagnetic substances and ordinary dust has no effect on it, this solution avoids the defect that the optical signal in the slot-type photoelectric switch is easily blocked by accumulated dust and fails in a high-dust environment.

[0030] For those skilled in the art, various corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all these changes and deformations should fall within the protection scope of the claims of this utility model.

Claims

1. A grooved Hall induction switch, characterized in that, Including: A housing, a permanent magnet, and a Hall switch element; The housing is made of a non-magnetic material, with a groove-shaped opening provided at the front end of the housing, and a cavity is provided on each side of the groove-shaped opening; The two cavities are respectively used for placing the permanent magnet and the Hall switch element; The magnetic pole of the permanent magnet that can induce the Hall switch element faces the Hall switch element.

2. The trough-shaped Hall induction switch according to claim 1, characterized in that, The width of the groove-shaped opening is 3 mm to 8 mm.

3. The trough-shaped Hall induction switch according to claim 2, wherein, The width of the groove-shaped opening is 4 mm.

4. A grooved Hall induction switch according to claim 1, characterized in that, The permanent magnet is a cylinder with a diameter of 2 to 4 mm and a height of 1 to 3 mm, and the magnetization direction is axial magnetization.

5. The grooved Hall induction switch according to claim 4, wherein The permanent magnet is a cylinder with a diameter of 3 mm and a height of 2 mm.

6. The trough-shaped Hall induction switch according to claim 5, wherein, The permanent magnet is made of neodymium iron boron material.

7. The trough-shaped Hall induction switch according to claim 1, characterized in that, The Hall switch element is a unipolar Hall effect switch or an omnipolar Hall effect switch.

8. A grooved Hall induction switch according to claim 1, characterized in that, The housing is made of plastic material.

9. A grooved Hall induction switch according to claim 8, characterized in that, The housing is made of translucent plastic material.

10. The trough-shaped Hall induction switch according to claim 9, characterized in that, An indicator light is provided inside the housing, and the indicator light is a light-emitting diode.

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