Contact type linear displacement sensor

Abstract

The utility model provides a contact type linear displacement sensor, which comprises a shell and a guide shaft, the guide shaft is provided with a contact in contact with a measured object, the shell is internally provided with a circuit board, a linear grating and a moving structure, a first end part of the shell is provided with a linear bearing, and a second end part of the shell is provided with a second linear bearing. The circuit board is provided with a receiver chip, an MCU chip and a protocol chip, the receiver chip is integrated with a blue-light LED luminescent tube and a subdivision device, the linear grating is arranged on the moving structure, the guide shaft penetrates through the linear bearing and is connected with the moving structure, and when external force is applied to the guide shaft, the guide shaft is connected with the linear bearing through the subdivision device. The guide shaft moves towards the second end part of the shell under the action of the external force so as to drive the moving structure and the linear grating to integrally move towards the second end part of the shell, the second end part and the first end part are oppositely arranged, and the receiver chip and the linear grating are oppositely arranged. According to the utility model, the measurement precision can be improved.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, and in particular to a contact linear displacement sensor. Background Technology

[0002] Currently, contact displacement sensors are widely used to measure the thickness and flatness of objects. Most current contact displacement sensors employ the red light through-beam principle, requiring the light source and receiver to be placed on opposite sides of a grating ruler. This separate layout of the light source and receiver leads to complex mechanical structures, and the red light wavelength limits resolution improvement. Furthermore, traditional sensors offer only a single signal output format, making it difficult to meet the needs of different scenarios. Utility Model Content

[0003] To address the aforementioned technical problems, the technical solution adopted by this utility model is as follows:

[0004] This utility model provides a contact linear displacement sensor, including: a housing and a guide shaft. The guide shaft is provided with a contact point that contacts the object being measured. The housing contains a circuit board, a linear grating, and a moving structure. A linear bearing is provided at the first end of the housing. A receiver chip, an MCU chip, and a protocol chip are provided on the circuit board. The receiver chip integrates a blue LED and a subdivision converter. The linear grating is disposed on the moving structure. The guide shaft passes through the linear bearing and is connected to the moving structure. When an external force is applied to the guide shaft, the guide shaft moves towards the second end of the housing under the action of the external force, thereby driving the moving structure and the linear grating as a whole to move towards the second end of the housing. The second end and the first end are arranged opposite to each other, and the receiver chip and the linear grating are arranged opposite to each other.

[0005] This utility model has at least the following beneficial effects:

[0006] This utility model provides a contact-type linear displacement sensor. A guide shaft moves linearly within a linear bearing, driving a moving structure and a linear grating to move linearly together. This creates a relative displacement between the linear grating and the receiver chip, which can be calculated to measure the target's displacement. Furthermore, the guide shaft and the moving structure are fixed together with screws, ensuring smooth linear movement without wobbling. Increasing the guide shaft's rigidity and surface finish, and ensuring a smooth transition fit with the linear bearing, reduces mechanical errors and guarantees motion accuracy. Additionally, the use of a reflective chip increases the optical slit between the chip and the linear grating, reducing assembly complexity. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 A schematic diagram of the structure of a contact linear displacement sensor provided in an embodiment of this utility model;

[0009] Figure 2 for Figure 1 A sectional view. Detailed Implementation

[0010] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0011] This utility model embodiment provides a contact-type linear displacement sensor, such as... Figure 1 and Figure 2 As shown, it includes: a housing 1 and a guide shaft 2. The guide shaft 2 is provided with a contact 3 that contacts the object being measured, and the housing 1 contains a circuit board 4, a linear grating 5, and a moving structure 6.

[0012] The housing 1 has a linear bearing 7 at its first end. The circuit board has a receiver chip 8, an MCU chip (not shown), and a protocol chip (not shown). The receiver chip integrates a blue LED (not shown) and a subdivision unit (not shown). The receiver chip and the linear grating are arranged opposite to each other. Specifically, the linear grating is arranged below the receiver chip.

[0013] In this embodiment of the invention, the receiver chip can be a reflective photoelectric absolute encoder chip. The blue LED and subdivision converter can be integrated and packaged on the reflective photoelectric absolute encoder chip. This integration of the light source and receiver chip on the same side simplifies the mechanical layout and enables miniaturization of the displacement sensor.

[0014] In this embodiment of the invention, no lens is provided on the blue LED. The wavelength of the blue LED can be 450nm. The subdivision converter can be an existing product, used to subdivide the reflected light signal to achieve nanometer-level resolution.

[0015] In this embodiment of the invention, the linear grating 5 is made of quartz glass and has an absolute code track (Gray code) and an incremental code track coated on its surface.

[0016] In this embodiment of the invention, after blue light is emitted, it is reflected by a linear grating. The reflected signal is received by the receiving channel on the receiver chip, forming a differential sine and cosine signal. The sine and cosine signal is subdivided and converted into a digital signal by a subdivision unit, which can achieve nanometer-level resolution, which is significantly higher than that of the traditional red light scheme.

[0017] In this embodiment of the invention, the MCU chip receives absolute data from the reflective photoelectric absolute encoder chip via the SPI interface and employs a sliding filter algorithm to eliminate jitter. The protocol chip outputs a custom protocol RS485 differential signal or an SSI protocol RS422 signal.

[0018] Furthermore, the circuit board is also equipped with a differential line driver chip (not shown). The differential line driver chip is used to output incremental signals, supports users to select the output format as needed, including TTL or HTL format, and the transmission distance can reach 100 meters.

[0019] Furthermore, the linear grating 5 is disposed on the movable structure 6, and the guide shaft 2 passes through the linear bearing 7 and is connected to the movable structure 6. When an external force is applied to the guide shaft, the guide shaft moves towards the second end of the housing under the action of the external force, thereby driving the movable structure to move towards the second end of the housing. The second end and the first end are disposed opposite to each other.

[0020] Furthermore, the guide shaft 2 and the moving structure 6 are fixedly connected by screws. This ensures smooth linear motion of the guide shaft without wobbling, increases its rigidity and surface finish, and allows for a smooth transition fit with the linear bearing, thus reducing mechanical errors and ensuring motion accuracy. In one specific embodiment, the guide shaft and the moving structure are fixedly connected by three screws.

[0021] In this embodiment of the invention, a retractable protective sleeve 9 is provided on the guide shaft 2 to protect the guide shaft.

[0022] In this embodiment of the invention, the movable structure can be a block structure. The linear grating is mounted on the movable structure to form an integral structure.

[0023] In this embodiment of the invention, the interior of the housing 1 is further provided with a first slide rail (not shown) and a second slide rail (not shown). The first slide rail is located on the side of the interior of the housing 1, and the second slide rail is located at the bottom of the interior of the housing 1, which may include two second slide rails. The side of the moving structure 6 is slidably connected to the first slide rail via a sliding rod (not shown), and the bottom of the moving structure is slidably connected to the second slide rail via a sliding block (not shown). This ensures that the guide shaft can move linearly stably.

[0024] Furthermore, the end of the movable structure is connected to the first end of the housing by a spring (not shown). The spring is used to restore the guide shaft. Specifically, relying on the elastic force of the spring, the movable structure can move towards the first end of the housing, thereby driving the guide shaft back to its initial position.

[0025] The contact linear displacement sensor provided by this utility model drives a linear grating to move linearly together through a guide shaft. This generates a relative displacement between the linear grating and the receiver chip. The displacement of the measured object can be measured by calculation. The specific calculation can be performed using existing technology.

[0026] In addition, the contact linear displacement sensor provided by this utility model may also include connectors, etc.

[0027] In practical use, the contact linear displacement sensor provided by this utility model can be fixed with a hexagonal nut. The sensor must be installed vertically on the measuring surface to avoid errors caused by lateral forces.

[0028] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A contact-type linear displacement sensor, characterized in that, include: The device comprises a housing and a guide shaft. The guide shaft has a contact point that contacts the object being measured. The housing contains a circuit board, a linear grating, and a moving structure. A linear bearing is located at the first end of the housing. A receiver chip, an MCU chip, and a protocol chip are mounted on the circuit board. The receiver chip integrates a blue LED and a subdivision converter. The linear grating is mounted on the moving structure. The guide shaft passes through the linear bearing and is connected to the moving structure. When an external force is applied to the guide shaft, the guide shaft moves towards the second end of the housing under the action of the external force, thereby driving the moving structure and the linear grating as a whole to move towards the second end of the housing. The second end and the first end are arranged opposite each other, and the receiver chip and the linear grating are arranged opposite each other.

2. The contact linear displacement sensor according to claim 1, characterized in that, The circuit board is also equipped with a differential line driver chip.

3. The contact linear displacement sensor according to claim 1, characterized in that, A retractable protective sleeve is provided on the guide shaft.

4. The contact linear displacement sensor according to claim 1, characterized in that, The blue LED light-emitting tube does not have a lens.

5. The contact linear displacement sensor according to claim 1, characterized in that, The guide shaft and the movable structure are fixedly connected by screws.

6. The contact linear displacement sensor according to claim 1, characterized in that, The housing is further provided with a first slide rail and a second slide rail. The side of the movable structure is slidably connected to the first slide rail via a sliding rod, and the bottom of the movable structure is slidably connected to the second slide rail via a sliding block.

7. The contact linear displacement sensor according to claim 1, characterized in that, The end of the movable structure is connected to the first end of the housing by a spring.

8. The contact linear displacement sensor according to claim 1, characterized in that, The receiver chip is a reflective photoelectric absolute encoder chip.

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