Grating-type high-precision contact-type displacement sensor

Abstract

The invention discloses a grating-type high-precision contact-type displacement sensor, and the sensor comprises a housing main body, a probe linear motion assembly, a grating code ruler assembly, a light transmitting and receiving assembly, a limiting groove assembly, and a mainboard assembly. A containing space is formed in the shell body, and the grating code ruler assembly, the light emitting and receiving assembly, the limiting groove assembly and the main board assembly are all arranged in the containing space. The grating code ruler assembly comprises a grating code ruler, a plurality of transparent lines and opaque lines are formed on the grating code ruler, and the coding mode of the grating code ruler adopts a mixed coding mode of incremental coding and absolute coding. According to the invention, a mixed coding mode is adopted by the grating code ruler, zero searching operation is not needed, and a probe linear motion structure capable of realizing precise transmission is matched, so that the sensor has the advantages of high repetition precision, good performance stability, high response speed and strong anti-interference capability.

Description

Technical Field

[0001] The present invention relates to the technical field of displacement sensors, and in particular to a grating type high-precision contact displacement sensor. Background Art

[0002] When working, the contact displacement sensor detects the displacement, deformation and other physical quantities of the object by contacting the object being detected. When the object moves or deforms, the mechanical structure inside the sensor will change accordingly, thereby changing the electrical characteristics of the sensor, and these changes are converted into readable electrical signal outputs through the circuit. At present, some precision grating line displacement measurement systems use incremental gratings to convert the physical quantity of linear displacement into moiré fringe light signals through optical interference, which are received by photoelectric devices and converted into electrical signals, and then sent to the signal processing circuit. After processing, the relative displacement is output. Most of the domestic linear grating rulers are incremental grating rulers. This type of grating ruler needs to be "zeroed" when turned on or reset, and there is a cumulative error phenomenon, which affects the accuracy of workpiece processing or measurement.

[0003] Therefore, the prior art has defects and needs to be improved. Summary of the invention

[0004] The object of the present invention is to overcome the deficiencies of the prior art and provide a grating type high-precision contact displacement sensor.

[0005] The technical solution of the present invention is as follows: The present invention provides a grating type high-precision contact displacement sensor, comprising: a housing body, a probe linear motion assembly, a grating code scale assembly, a light emitting and receiving assembly, a limit slot assembly and a mainboard assembly;

[0006] An accommodating space is formed in the shell body, and the grating code scale component, the light emitting and receiving component, the limiting groove component and the mainboard component are all arranged in the accommodating space.

[0007] The grating code scale component comprises a grating code scale, on which a plurality of transparent lines and opaque lines are formed, and the encoding method thereof adopts an encoding method of a mixed encoding of incremental encoding and absolute encoding.

[0008] The probe linear motion assembly includes a measuring head for contacting the measured object, and the probe linear motion assembly is connected to the grating code scale. When the measured object is displaced, the grating code scale is driven by the probe linear motion assembly to perform linear motion;

[0009] The limiting groove assembly is used to prevent the probe linear motion assembly from rotating.

[0010] The light emitting and receiving component includes a light emitting module and a light receiving module which are arranged correspondingly. The light emitting module is used to emit light, and the light receiving module is used to receive light and convert it into an electrical signal. The grating code is located between the light emitting module and the light receiving module.

[0011] The mainboard component is electrically connected to the light receiving module and is used for decoding and processing the electrical signal of the light receiving module and then outputting it.

[0012] Furthermore, the probe linear motion assembly also includes: a shaft, a sleeve and a guide ball bushing, the sleeve is fixed on the shell body, the shaft is fixed in the guide ball bushing, the guide ball bushing is arranged in the sleeve and can slide relative to the sleeve, and the shaft is fixed to the measuring head and the grating code scale.

[0013] Furthermore, the grating code scale assembly further comprises a code scale bracket, and the code scale bracket connects the shaft and the grating code scale.

[0014] Furthermore, the limiting groove assembly includes a limiting pin and a groove body, the groove body is fixed to the inner wall of the accommodating space, a limiting groove is formed on the groove body, and the limiting pin is fixed to the yardstick bracket and can slide in the limiting groove.

[0015] Furthermore, the solution also includes a dust cover, which is sleeved on the shaft and located between the measuring head and the shaft sleeve.

[0016] Furthermore, the light emitting and receiving assembly further comprises an optical path bracket, and the light emitting module and the light receiving module are both arranged on the optical path bracket.

[0017] Furthermore, the light emitting module includes a light emitting light source board and a focusing lens, the focusing lens is arranged on the optical path of the light emitted by the light emitting light source board to focus the light, and the light receiving module includes a CMOS receiver.

[0018] Furthermore, the solution also includes a light guide column, which is arranged on the shell body and is used to guide the light in the accommodating space out.

[0019] Furthermore, the line width accuracy of each line of the grating code scale is within ±1um, and the position accuracy of adjacent lines is within ±0.1um.

[0020] Furthermore, the solution also includes a connector, which is arranged on the shell body and is electrically connected to the mainboard assembly.

[0021] By adopting the above scheme, the beneficial effects of the present invention are: the grating code scale adopts a hybrid coding encoding method, without the need for a "zero search" operation, and is combined with a probe linear motion structure that can achieve precise transmission, so that the sensor has the advantages of high repeatability, good performance stability, high-speed response speed, and strong anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention.

[0023] Figure 2 for Figure 1 Cross-sectional view at AA in the middle.

[0024] Figure 3 Schematic diagram of the structure of the grating code ruler. DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0026] Please refer to Figures 1 to 3 In this embodiment, the present invention provides a grating type high-precision contact displacement sensor, including: a shell body 1, a probe linear motion component, a grating code scale 10 component, a light emitting and receiving component, a limit groove component and a mainboard component.

[0027] An accommodating space is formed in the shell body 1, and the grating code scale 10 component, the light emitting and receiving component, the limit groove component and the main board component are all arranged in the accommodating space.

[0028] The grating scale 10 assembly includes a grating scale 10 and a scale support 8, and the grating scale 10 is arranged on the scale support 8. The material of the grating scale 10 is glass. A number of transparent lines and opaque lines are formed on the grating scale 10, and its encoding method adopts an encoding method of a mixed encoding of incremental encoding and absolute encoding, which not only ensures the uniqueness and advancement of the position, but also the decoding method is very simple and efficient, and the decoding speed is as high as 2000 times / s. The realization of high-speed decoding ensures that the product can respond to the test at a high speed, and there is no need to "seek zero" when the product is turned on or reset, and there is no cumulative error phenomenon. The line width accuracy of each line is within ±1um, the position accuracy of adjacent lines is within ±0.1um, and there is no cumulative error, so that the sensor accuracy can meet ±2um, ensuring the high precision of the product.

[0029] The probe linear motion assembly includes a shaft 4, a sleeve 2, a guide ball bushing 2, and a measuring head 7 for contacting the object to be measured. The material of the measuring head 7 is tungsten steel, which can avoid the situation where the wear and tear after repeated use causes inaccurate measurement. The sleeve 2 is fixed on the shell body 1, and the shaft 4 is fixed in the guide ball bushing 2. The guide ball bushing 2 is arranged in the sleeve 2 and can slide relative to the sleeve 2. The guide ball bushing 2 is a precision micro guide ball bushing 2. After the assembly, the probe linear motion assembly has the advantages of high coaxiality and can achieve high-precision sliding fit. The shaft 4 is fixed to the measuring head 7 and the yardstick bracket 8. When the object to be measured is displaced or deformed, the grating yardstick 10 is driven to perform linear motion through the probe linear motion assembly.

[0030] The limit groove assembly is used to prevent the rotation of the probe linear motion assembly and can limit the motion stroke of the probe linear motion assembly. Specifically, the limit groove assembly includes a limit pin 9 and a groove body 11, the groove body 11 is fixed to the inner wall of the accommodating space, and a limit groove is formed on the groove body 11. The limit pin 9 is fixed to the yardstick bracket 8 and can slide in the limit groove. The limit groove can limit the rotation of the positioning pin to limit the rotation of the probe linear motion assembly, thereby ensuring the detection accuracy of the sensor, and the inner walls of the two ends of the groove body 11 can block the positioning pin, thereby limiting the motion stroke of the probe linear motion assembly.

[0031] The light emitting and receiving component includes a corresponding light emitting module and a light receiving module. The light emitting module is used to emit light, and the light receiving module is used to receive light and convert it into an electrical signal. The grating code ruler 10 is located between the light emitting module and the light receiving module. The light emitting and receiving component also includes an optical path bracket 12. The light emitting module and the light receiving module are both arranged on the optical path bracket 12. This structural arrangement makes the light emitting and receiving component modular, and has the advantages of easy installation and reliable use. The light emitting module includes a light emitting light source board 13 and a focusing lens 14. The focusing lens 14 is arranged on the optical path of the light emitted by the light emitting light source board 13 to focus the light. The light receiving module includes a CMOS receiver 15, which can achieve high-sensitivity signal reception.

[0032] The mainboard component is electrically connected to the light receiving module, and includes a single-chip microcomputer device, which is used for decoding and processing the electrical signal of the light receiving module and then outputting it.

[0033] Furthermore, the solution also includes a dust cover 6 , which is sleeved on the shaft 4 and located between the measuring head 7 and the shaft sleeve 2 , and is installed through a plug 5 .

[0034] Furthermore, the solution also includes a light guide column 16, which is arranged on the shell body 1 and is used to guide the light emitted by the light emitting module in the accommodating space, so that the working status of the sensor can be easily observed from the outside.

[0035] Furthermore, the solution also includes a connector 17, which is arranged on the shell body 1 and electrically connected to the mainboard assembly, and is used to realize the electrical connection between the sensor and the outside.

[0036] Please refer to Figures 1 to 3 When the sensor in this scheme is working, the measuring head 7 contacts the object to be measured. When the object to be measured is unique, the grating code ruler 10 is driven to move through the shaft 4. Since the light emitted by the light emitting module will pass through the grating code ruler 10 and then reach the light receiving module, the movement of the grating code ruler 10 will cause the light received by the light receiving module to change, thereby generating different electrical signals and sending them to the mainboard component. The mainboard component processes the electrical signals and outputs them to achieve displacement measurement.

[0037] To sum up, the beneficial effects of the present invention are: the grating code scale adopts a hybrid coding encoding method, without the need for a "zero search" operation, and is combined with a probe linear motion structure that can achieve precise transmission, so that the sensor has the advantages of high repeatability, good performance stability, high-speed response speed, and strong anti-interference ability.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A grating type high-precision contact displacement sensor, characterized in that: include: Shell body, probe linear motion assembly, grating scale assembly, light emitting and receiving assembly, limit slot assembly and mainboard assembly; An accommodating space is formed in the shell body, and the grating code scale component, the light emitting and receiving component, the limit groove component and the main board component are all arranged in the accommodating space; The grating code scale assembly includes a grating code scale, on which a plurality of transparent lines and opaque lines are formed, and the encoding method thereof adopts an encoding method of a mixed encoding of incremental encoding and absolute encoding; The probe linear motion assembly includes a measuring head for contacting the measured object, and the probe linear motion assembly is connected to the grating code scale. When the measured object is displaced, the grating code scale is driven to perform linear motion by the probe linear motion assembly. The limit groove assembly is used to prevent the probe linear motion assembly from rotating; The light emitting and receiving assembly comprises a light emitting module and a light receiving module which are arranged correspondingly, wherein the light emitting module is used to emit light, and the light receiving module is used to receive light and convert it into an electrical signal, and the grating code ruler is located between the light emitting module and the light receiving module; The mainboard component is electrically connected to the light receiving module and is used for decoding and processing the electrical signal of the light receiving module and then outputting it.

2. The grating type high-precision contact displacement sensor according to claim 1, characterized in that: The probe linear motion assembly also includes: a shaft, a sleeve and a guide ball bushing, the sleeve is fixed on the shell body, the shaft is fixed in the guide ball bushing, the guide ball bushing is arranged in the sleeve and can slide relative to the sleeve, and the shaft is fixed to the measuring head and the grating code scale.

3. The grating type high-precision contact displacement sensor according to claim 2, characterized in that: The grating code scale assembly further comprises a code scale bracket, and the code scale bracket connects the shaft and the grating code scale.

4. The grating type high-precision contact displacement sensor according to claim 3, characterized in that: The limiting groove assembly comprises a limiting pin and a groove body, wherein the groove body is fixed to the inner wall of the accommodating space, a limiting groove is formed on the groove body, and the limiting pin is fixed to the yardstick bracket and can slide in the limiting groove.

5. The grating type high-precision contact displacement sensor according to any one of claims 2 to 4, characterized in that: It also includes a dust cover, which is sleeved on the shaft and located between the measuring head and the shaft sleeve.

6. The grating type high-precision contact displacement sensor according to any one of claims 1 to 4, characterized in that: The light emitting and receiving assembly further comprises an optical path bracket, and the light emitting module and the light receiving module are both arranged on the optical path bracket.

7. The grating type high-precision contact displacement sensor according to claim 6, characterized in that: The light emitting module comprises a light emitting source board and a focusing lens, wherein the focusing lens is arranged on the optical path of the light emitted by the light emitting source board for focusing the light, and the light receiving module comprises a CMOS receiver.

8. The grating type high-precision contact displacement sensor according to any one of claims 1 to 4, characterized in that: It also includes a light guide column, which is arranged on the shell body and is used to guide the light in the accommodating space out.

9. The grating type high-precision contact displacement sensor according to any one of claims 1 to 4, characterized in that: The line width accuracy of each line of the grating code is within ±1um, and the position accuracy of adjacent lines is within ±0.1um.

10. The grating type high-precision contact displacement sensor according to any one of claims 1 to 4, characterized in that: It also includes a connector, which is arranged on the shell body and is electrically connected to the mainboard assembly.

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