Fixed gate device of electronic digital caliper

Abstract

The utility model discloses a fixed gate device of an electronic digital caliper, which comprises a fixed gate body, a group of incremental coding gates and a group of position coding gates are arranged on the fixed gate body, and the incremental coding gates and the position coding gates are arranged in parallel; the incremental coding grid is a row of rectangular metal sheets which are arranged at equal intervals and have the same size, and the center-to-center distance between the adjacent rectangular metal sheets is a pitch p; the length of a single position coding grid is a, the edge distance between adjacent position coding grids is b, a = N * p, b = M * p, and N and M are positive integers. According to the utility model, high-precision absolute position measurement can be realized by using the two coding grids, the manufacturing is simple, and the cost is very low.

Description

Technical Field

[0001] The utility model relates to the technical field of measuring instruments, in particular to a fixed grid device of an electronic digital caliper. Background Art

[0002] The existing publication number CN217764718U discloses a fixed grid device for an electronic digital caliper, which can improve product stability, ensure measurement accuracy, and is easy to use. It includes a fixed grid body, on which a group of incremental grids are provided. The incremental grids are a row of rectangular metal sheets arranged at equal intervals. Two groups of absolute grids are also provided on the fixed grid body. Each group of absolute grids includes a row of strip metal blocks. The strip metal blocks of the two groups of absolute grids are staggered up and down along the arrangement direction of the incremental grids. When one group of absolute grids is projected to the position of the other group of absolute grids, a continuous long strip of metal block is formed. Suppose the length of a single absolute grid is a, and the distance between the centers of two adjacent incremental grids is b, then a=N*b, where N is a positive integer, and the two ends of each absolute grid are aligned with the end face of the same end of two different incremental grids. The length of the incremental grid and the absolute grid is greater than 30 cm.

[0003] Conventional digital calipers use incremental encoding, requiring the measurement circuit to operate continuously to ensure accurate measurements. The zero position is the new zero position after power is cycled, making them inadequate for absolute position measurement. Some absolute position digital calipers use complex fixed-grid encoding, requiring high precision and requiring specialized chips. Utility Model Content

[0004] The purpose of the utility model is to provide a fixed grid device for an electronic digital caliper to solve the problems in the prior art.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a fixed grid device for an electronic digital caliper, comprising a fixed grid body, on which a group of incremental coding grids and a group of position coding grids are provided, wherein the incremental coding grids and the position coding grids are arranged in parallel;

[0006] The incremental encoding grid is a row of rectangular metal pieces of the same size arranged at equal intervals, and the center distance between adjacent rectangular metal pieces is a pitch p;

[0007] The length of a single position coding grid is a, and the margin between adjacent position coding grids is b, then a=N*p, b=M*p, where N and M are both positive integers.

[0008] Preferably, the length and side spacing of each metal piece of the position coding grid are positive multiples of the pitch, and the height of each metal piece of the position coding grid is the same.

[0009] Preferably, a starting point of the rectangular metal sheet of each position encoding grid is aligned with a starting point of the rectangular metal sheet of an incremental encoding grid.

[0010] Compared with the prior art, the beneficial effects of the present invention are: a group of incremental coding grids and a group of position coding grids are arranged on the fixed grid body, and the incremental coding grids and the position coding grids are arranged in parallel; the use of two coding grids can achieve high-precision absolute position measurement, and the manufacturing is simple and the cost is very low. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0012] Figure 1 It is a structural diagram of the present utility model.

[0013] In the figure: 1. Incremental encoding grid; 2. Position encoding grid. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the utility model for which protection is claimed, but merely represents selected embodiments of the present invention.

[0015] See also Figure 1 In an embodiment of the present invention, a fixed grid device of an electronic digital caliper includes a fixed grid body, on which a group of incremental coding grids 1 and a group of position coding grids 2 are provided, and the incremental coding grids 1 and the position coding grids 2 are arranged in parallel;

[0016] The incremental encoding grid 1 is a row of rectangular metal sheets of the same size arranged at equal intervals, and the center distance between adjacent rectangular metal sheets is a pitch p;

[0017] The length of a single position coding grid 2 is a, and the margin between adjacent position coding grids 2 is b, then a=N*p, b=M*p, where N and M are both positive integers.

[0018] The length and side spacing of each metal sheet of the position coding grid 2 are positive multiples of the pitch, and the height of each metal sheet of the position coding grid 2 is the same; the starting point of each rectangular metal sheet of the position coding grid 2 is aligned with the starting point of a rectangular metal sheet of an incremental coding grid 1.

[0019] The incremental encoder grid is a row of rectangular metal plates of the same size arranged at equal intervals. The incremental encoder grid repeats periodically with equal spacing, and the center-to-center spacing is called the pitch, denoted by the letter p. The position encoder grid is a row of rectangular metal plates of varying lengths but the same height, arranged at unequal intervals. Let the length of a single position encoder grid be a, and the margin between adjacent position encoder grids be b. Then a = N*p, and b = M*p, where N and M are positive integers. This means that the length and margin spacing of each metal plate in the position encoder grid are positive multiples of the pitch. Furthermore, the starting point of each rectangular metal plate in the position encoder grid must align with the starting point of a rectangular metal plate in the incremental encoder grid. There are no restrictions on the lengths of incremental and position encoder grids.

[0020] The order of rectangular metal sheets of each length in the position coding grid can be adjusted as needed, and there is no fixed requirement. The detection plate can be capacitive or inductive.

[0021] The incremental encoder is used to measure the position within a pitch p, represented by m. The position encoder is used to determine the current position within the pitch, represented by n. The actual absolute position x = n*p+m.

[0022] For example: if 64 pitches need to be detected, the position coding grids can be arranged in the order shown in the figure. If there is no metal piece at the position of the position coding grid corresponding to each pitch, we define this situation as 0, and the situation with a metal piece is 1. At least 6 detection plates are required to read out 64 different codes; the detection plate moves from left to right, starting from the initial position, the detection plate will read 000011, and after moving one pitch, it will read 000111. Continuing to move will read in sequence: 001111, 011110, 11110, and 64 non-repeating codes can be obtained.

[0023] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A fixed grid device for an electronic digital caliper, comprising a fixed grid body, characterized in that: A set of incremental coding grids (1) and a set of position coding grids (2) are provided on the fixed grid body, and the incremental coding grids (1) and the position coding grids (2) are provided in parallel; The incremental encoding grid (1) is a row of rectangular metal sheets of the same size arranged at equal intervals, and the center distance between adjacent rectangular metal sheets is a pitch p; The length of a single position coding grid (2) is a, and the margin between adjacent position coding grids (2) is b, then a=N*p, b=M*p, where N and M are both positive integers.

2. The fixed grid device of an electronic digital caliper according to claim 1, characterized in that: The length and side spacing of each metal piece of the position coding grid (2) are positive multiples of the pitch, and the height of each metal piece of the position coding grid (2) is the same.

3. The fixed grid device of an electronic digital caliper according to claim 2, characterized in that: The starting point of the rectangular metal sheet of each position encoding grid (2) is aligned with the starting point of the rectangular metal sheet of an incremental encoding grid (1).

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