Displacement sensor based on grating

Abstract

The utility model discloses a grating-based displacement sensor, which relates to the technical field of sensors and comprises a sensor shell, a sealing cover is hinged to the outer surface of the sensor shell through a hinge, a displacement rod is slidably connected into the sensor shell, a movable grating is arranged in the sensor shell, and the movable grating is connected with the sealing cover through a hinge. A scale grating is fixedly connected to the outer surface of the sealing cover, a limiting mechanism is arranged in the sensor shell, the limiting mechanism comprises a main control board, and a set of connecting rods are fixedly connected to the bottom face of the main control board. Through the arrangement of the main control board, the limiting column, the limiting groove and the telescopic spring, the disassembly efficiency of a sensor shell by a worker is greatly improved, internal elements of the sensor are convenient to overhaul and replace, the situation that the overall use of the sensor is affected due to damage of a single part is avoided, the use cost of the sensor is saved, and the practicability of the sensor is improved. And the measurement accuracy of the displacement sensor is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically a displacement sensor based on a grating. Background Technology

[0002] A grating displacement sensor, or grating ruler for short, is a measurement feedback device that works using the optical principle of a grating. It can meet various measurement and control feedback needs, including contact, non-contact, small range, large range, one-dimensional, and multi-dimensional requirements. It is widely used in many fields such as programmable logic controllers (PLCs), CNC machine tools and coordinate measuring machines (CMMs), precision measurement and positioning, ultra-precision machining, quality inspection, nanomaterials, and robotics.

[0003] According to patent CN221123319U, a fiber optic displacement sensor based on a blazed grating is disclosed, which includes a first mounting bracket and a second mounting bracket arranged on the left and right sides respectively. An optical fiber is horizontally arranged on the end face of the first mounting bracket facing the second mounting bracket, and a blazed grating is vertically arranged on the end face of the second mounting bracket facing the first mounting bracket.

[0004] The aforementioned solution ensures that the grating remains in position during displacement, improving measurement accuracy. However, it also makes it inconvenient to inspect and repair the internal components of the sensor, often rendering the entire sensor unusable due to a problem with a single internal component, significantly increasing operating costs. Therefore, we provide a grating-based displacement sensor to address these issues. Summary of the Invention

[0005] The purpose of this invention is to provide a grating-based displacement sensor to solve the problems raised in the prior art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a displacement sensor based on a grating, comprising a sensor housing, a sealing cover hinged to the outer surface of the sensor housing, a displacement rod slidably connected inside the sensor housing, a movable grating disposed inside the sensor housing, a scale grating fixedly connected to the outer surface of the sealing cover, a limiting mechanism disposed inside the sensor housing, the limiting mechanism comprising a main control board, a set of connecting rods fixedly connected to the bottom surface of the main control board, each connecting rod being slidably connected to the sensor housing, a limiting post fixedly connected to the bottom end of each connecting rod, and a set of limiting grooves opened on the top surface of the sealing cover, each limiting post being slidably connected to the limiting groove.

[0007] Preferably, a fixed cover is slidably connected to the outer surface of each connecting rod, and each fixed cover is fixedly connected to the sensor housing, the fixed cover providing a limiting effect for the sliding of the connecting rod.

[0008] Preferably, each of the connecting rods is fitted with a telescopic spring on its outer surface, and the two ends of each telescopic spring are fixedly connected to the limiting post and the fixing cover, respectively. The telescopic spring plays the role of pushing the limiting post to be stably inserted into the limiting groove.

[0009] Preferably, a connecting block is fixedly connected to the outer surface of the movable grating, and the connecting block is fixedly connected to the displacement rod, so that the connecting block can support the movable grating.

[0010] Preferably, an optical element is fixedly mounted on the outer surface of the sealing cover, and a light source generator is fixedly mounted on the inner wall of the sensor housing, the light source generator providing a light source for the use of the device.

[0011] Preferably, a ball bearing is fixedly connected to the outer surface of the sensor housing, and the displacement rod passes through the ball bearing and is slidably connected to the ball bearing. The ball bearing can effectively improve the measurement accuracy of the device.

[0012] Preferably, an extension sleeve is fixedly connected to the outer surface of the sensor housing, and the displacement rod slides inside the extension sleeve, with the extension sleeve supporting the sliding of the displacement rod.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. This application, through the design of the main control board, limit post, limit groove and telescopic spring, greatly improves the efficiency of the staff in disassembling the sensor housing, facilitates the inspection and replacement of the internal components of the sensor, avoids the impact of a single part damage on the overall use of the sensor, saves the use cost of the sensor, and effectively improves the measurement accuracy of the displacement sensor.

[0015] 2. The movable grating and scale grating of this application can utilize the change in light intensity when the movable grating and scale grating are relatively displaced to react to the displacement of the object. The reaction interval is much larger than the grating pitch itself, thereby realizing the displacement amplification effect and facilitating high-precision detection.

[0016] 3. By incorporating ball bearings and an extension sleeve, this application achieves a stable gap between the displacement rod and the sensor housing, reducing friction between them. The extension sleeve provides support and limits for the movement of the displacement rod, facilitating precise transmission of object displacement and effectively improving the sensor's detection accuracy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a partial structural exploded view of the present invention;

[0019] Figure 3 This is a schematic diagram of the internal structure of the sensor housing of this utility model;

[0020] Figure 4 This is a schematic diagram of the limiting mechanism of this utility model;

[0021] Figure 5 This is a partial structural schematic diagram of the limiting mechanism of this utility model.

[0022] The following are the labels in the diagram: 1. Sensor housing; 2. Sealing cover; 3. Displacement rod; 4. Moving grating; 5. Scale grating;

[0023] 6. Limiting mechanism; 601. Main control board; 602. Connecting rod; 603. Limiting post; 604. Limiting groove; 605. Fixing cover; 606. Telescopic spring;

[0024] 7. Connecting block; 8. Optical element; 9. Light source generator; 10. Ball bearing; 11. Extension sleeve. Detailed Implementation

[0025] 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 of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] This invention provides a technical solution for a displacement sensor based on a grating.

[0027] like Figure 1 - Figure 5 As shown, the sensor includes a sensor housing 1. A sealing cover 2 is hinged to the outer surface of the sensor housing 1. A handle is installed on the outer surface of the sealing cover 2. The operator can open the sealing cover 2 through the handle to inspect the internal components of the sensor housing 1. When the sealing cover 2 is closed, it can maintain good stability and airtightness with the sensor housing 1, which can prevent external contaminants such as dust and oil from entering the sensor housing 1 and ensure that the measurement accuracy of the sensor is not affected.

[0028] A displacement rod 3 is slidably connected inside the sensor housing 1, and a ball bearing 10 is fixedly connected to the outer surface of the sensor housing 1. The displacement rod 3 passes through the ball bearing 10 and is slidably connected to the ball bearing 10. The ball bearing 10 can maintain a stable gap between the displacement rod 3 and the sensor housing 1, reduce the friction between the displacement rod 3 and the sensor housing 1, and facilitate the displacement rod 3 to accurately transmit the displacement of the object, effectively improving the detection accuracy of the sensor.

[0029] An extension sleeve 11 is fixedly connected to the outer surface of the sensor housing 1. The displacement rod 3 slides inside the extension sleeve 11. The friction between the extension sleeve 11 and the displacement rod 3 is small. The extension sleeve 11 provides space for the sliding of the displacement rod 3, so that the device can measure the displacement distance of the object by the distance that the object being measured drives the displacement rod 3 to slide.

[0030] The sensor housing 1 has a movable grating 4 inside, and a scale grating 5 is fixedly connected to the outer surface of the sealing cover 2. The principle of grating detection is as follows: when the movable grating 4 is displaced, the light generated by the light source generator 9 will be superimposed between the movable grating 4 and the scale grating 5 to produce alternating bright and dark moiré fringes. The periodic change of these fringes can reflect the magnitude of the displacement of the movable grating 4. The spacing between the fringes is much larger than the grating pitch itself, thereby realizing the displacement amplification effect and facilitating high-precision detection.

[0031] A connecting block 7 is fixedly connected to the outer surface of the movable grating 4. The connecting block 7 is fixedly connected to the displacement rod 3. When the connecting block 7 is activated, the displacement rod 3 moves under external pressure, and the movable grating 4 moves inside the sensor housing 1 through the connecting block 7. This facilitates the displacement change between the movable grating 4 and the scale grating 5, so that the device can detect the displacement distance of the object based on the moiré fringes.

[0032] An optical element 8 is fixedly mounted on the outer surface of the sealing cover 2. The optical element 8 can convert light signals into electrical signals. Specifically, through the cooperation of a grating, an infrared diode, and a phototransistor, the intensity changes of the moiré fringes are converted into four sinusoidal electrical signals. The phase difference of these signals can determine the direction of motion, while the zero-position window independently provides a reference pulse to achieve absolute position positioning. After amplification and shaping, the signals are output as square waves or sine waves for subsequent processing by the digital display system.

[0033] A light source generator 9 is fixedly installed on the inner wall of the sensor housing 1. The light source generator 9 provides a light source for the use of the device, enabling the moving grating 4 and the scale grating 5 to measure the displacement of the object through the principles of light interference and diffraction. A receiving component is also installed inside the sensor housing 1. The receiving component captures changes in light intensity and generates an electrical signal, which is ultimately converted into a displacement value by a digital display. All electrical components involved in this application are prior art and will not be described in detail here. Their specific working principles, connection methods, and installation positions should be determined according to actual conditions. The accompanying drawings are for reference only.

[0034] The sensor housing 1 is equipped with a limiting mechanism 6 inside. The limiting mechanism 6 includes a main control board 601. A handle is fixedly installed on the top surface of the main control board 601, which allows the operator to pull up the main control board 601. After the main control board 601 is pulled up, it can drive the limiting mechanism 6 to release the state of the locking seal cover 2. At this time, the operator can easily open the seal cover 2 and perform maintenance work on the internal components of the sensor housing 1.

[0035] A set of connecting rods 602 are fixedly connected to the bottom surface of the main control board 601. Each connecting rod 602 is slidably connected to the sensor housing 1. The connecting rods 602 serve to connect the main control board 601 and the limiting post 603. When the main control board 601 is pulled up, the limiting post 603 can be driven to rise through the connecting rods 602, so that the limiting post 603 slides out of the limiting groove 604, thereby making it convenient for the staff to open the sealing cover 2.

[0036] Each connecting rod 602 has a fixed limit post 603 at its bottom end. The top surface of the sealing cover 2 has a set of limit grooves 604. Each limit post 603 is slidably connected to the limit groove 604. The bottom end of the limit post 603 is hemispherical, and the top end of the sealing cover 2 is also rounded. When the sealing cover 2 is closed, the limit post 603 will compress the telescopic spring 606 under the pressure of the sealing cover 2, thereby retracting into the interior of the sensor housing 1. When the sealing cover 2 is fully closed, the limit groove 604 corresponds exactly to the position of the limit post 603. At this time, the limit post 603 will be pushed into the limit groove 604 by the telescopic spring 606, thereby ensuring the connection stability between the sealing cover 2 and the sensor housing 1.

[0037] Each connecting rod 602 has a fixed cover 605 slidably connected to its outer surface. Each fixed cover 605 is fixedly connected to the sensor housing 1. The fixed cover 605 provides limits and support for the lifting and lowering of the connecting rod 602, so that the connecting rod 602 can remain stable during transmission.

[0038] Each connecting rod 602 has a telescopic spring 606 fitted on its outer surface. The two ends of each telescopic spring 606 are fixedly connected to the limiting post 603 and the fixing cover 605, respectively. The telescopic spring 606 drives the limiting post 603 to be stably inserted into the limiting groove 604. The part of the limiting post 603 inserted into the limiting groove 604 is relatively long. The small amplitude of wobbling caused by the characteristics of the telescopic spring 606 itself is within the acceptable range of this application and will not affect the insertion operation of the limiting post 603.

[0039] Working principle: The operator first installs the device in a suitable working position. When an external object touches the end of the displacement rod 3, the displacement rod 3 will slide inside the sensor housing 1 under force. This sliding motion of the displacement rod 3 causes the moving grating 4 to move. When the moving grating 4 moves, the light source generated by the light source generator 9 will superimpose between the moving grating 4 and the scale grating 5, producing moiré fringes. The receiving component can generate an electrical signal based on the change in light intensity, which is ultimately converted into a displacement value by a digital display. When a component inside the sensor malfunctions and needs repair or replacement, the operator first pulls the main... The control board 601 rises, causing the connecting rod 602 to rise as well. The connecting rod 602 causes the limiting post 603 to disengage from the limiting groove 604. At this time, the staff can easily open the sealing cover 2. After the maintenance is completed, the staff pushes the sealing cover 2 back to its original position. The top of the sealing cover 2 will squeeze the limiting post 603. After the sealing cover 2 is completely closed, the limiting post 603 will be pushed into the limiting groove 604 by the telescopic spring 606, thus completing the fixation of the sealing cover 2. This greatly facilitates the staff's maintenance of the internal parts of the sensor.

[0040] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A displacement sensor based on a grating, characterized in that: The sensor housing (1) includes a sealing cover (2) hinged to the outer surface of the sensor housing (1), a displacement rod (3) slidably connected inside the sensor housing (1), a movable grating (4) provided inside the sensor housing (1), a scale grating (5) fixedly connected to the outer surface of the sealing cover (2), and a limit mechanism (6) provided inside the sensor housing (1). The limiting mechanism (6) includes a main control board (601), and a set of connecting rods (602) are fixedly connected to the bottom surface of the main control board (601). Each connecting rod (602) is slidably connected to the sensor housing (1), and a limiting post (603) is fixedly connected to the bottom end of each connecting rod (602).

2. The displacement sensor based on a grating according to claim 1, characterized in that: Each of the connecting rods (602) has a fixed cover (605) slidably connected to its outer surface, and each fixed cover (605) is fixedly connected to the sensor housing (1).

3. A grating-based displacement sensor according to claim 2, characterized in that: Each of the connecting rods (602) has a telescopic spring (606) fitted on its outer surface, and the two ends of each telescopic spring (606) are fixedly connected to the limiting post (603) and the fixing cover (605) respectively.

4. A grating-based displacement sensor according to claim 1, characterized in that: A connecting block (7) is fixedly connected to the outer surface of the movable grating (4), and the connecting block (7) is fixedly connected to the displacement rod (3).

5. A grating-based displacement sensor according to claim 1, characterized in that: An optical element (8) is fixedly installed on the outer surface of the sealing cover (2), and a light source generator (9) is fixedly installed on the inner wall of the sensor housing (1). A set of limiting grooves (604) is opened on the top surface of the sealing cover (2), and each limiting post (603) is slidably connected to the limiting groove (604).

6. A grating-based displacement sensor according to claim 1, characterized in that: The outer surface of the sensor housing (1) is fixedly connected to a ball bearing (10), and the displacement rod (3) passes through the ball bearing (10) and is slidably connected to the ball bearing (10).

7. A grating-based displacement sensor according to claim 1, characterized in that: An extension sleeve (11) is fixedly connected to the outer surface of the sensor housing (1), and the displacement rod (3) slides inside the extension sleeve (11).

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