Linear inductance type encoder
By drawing the main code track coil and the cursor code track coil in staggered overlapping layers and electrically connecting them through vias, the problem of large layout area of the inductive encoder is solved and the miniaturization design of the inductive encoder is achieved.
Patent Information
- Application Number
- CN202422632943.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-10-30
AI Technical Summary
In the prior art, the main track coil and the vernier track coil of the absolute linear displacement encoder are drawn side by side, resulting in a large layout area and making it difficult to achieve miniaturization of the inductive encoder.
The main code channel coil and the vernier code channel coil are drawn in staggered and overlapping layers, and are electrically connected through vias to reduce the layout area of the receiving coil and achieve a compact layout of the coil using a multi-layer PCB substrate.
The coil layout area of the inductive encoder is effectively reduced, and the miniaturization design of the inductive encoder is realized.
Smart Images
Figure CN223485197U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of inductive encoders, and in particular to a linear inductive encoder. Background Technology
[0002] Inductive encoders, also known as electromagnetic induction encoders, operate on the principle of electromagnetic induction. A current-carrying conductor generates a magnetic field, and the movement of the rotor affects this magnetic field, creating a voltage difference. This voltage difference is then converted into a mechanical signal. The basic principle is similar to that of a traditional rotary transformer, but instead of copper wire coil windings, it utilizes PCB technology to achieve dense coil windings.
[0003] Currently, the main code track coil and vernier code track coil of common absolute linear displacement encoders are drawn side by side. The two receiving coils each have their own excitation coils, and the two excitation coils need to be separated by a distance to avoid the alternating magnetic fields of the two excitation coils from affecting each other. This will greatly increase the layout area of the two coils, which is not conducive to the miniaturization of inductive encoders and also not conducive to the application of customers. Utility Model Content
[0004] To address the aforementioned problems, this utility model provides a linear inductive encoder, which solves the problem that the parallel coil drawing method in the prior art results in a large board area requirement, making it difficult to miniaturize the inductive encoder.
[0005] This utility model provides a linear inductive encoder, comprising: a mover and a stator. The stator includes a first PCB substrate, a plurality of excitation coils and a receiving coil disposed on the first PCB substrate, wherein the first PCB substrate is a multilayer board; the plurality of excitation coils are drawn in staggered layers and are electrically connected through vias; the receiving coil includes a main code track coil and a vernier code track coil; the main code track coil and the vernier code track coil are drawn in staggered and overlapping layers; the mover includes a second PCB substrate and a plurality of copper foils disposed on the substrate, the copper foils being arranged at equal intervals on the second PCB substrate to form periodic etched lines.
[0006] Preferably, each graduation of the periodic scale consists of 50% copper foil and 50% substrate.
[0007] Preferably, the first PCB substrate is a six-layer board.
[0008] Preferably, the excitation coil is a two-turn rectangular coil.
[0009] Preferably, the excitation coils are drawn in a counterclockwise direction between different first PCB substrate layers, and the end of the previous excitation coil is connected to the starting point of the next excitation coil through a via.
[0010] Preferably, the receiving coil and the excitation coil are drawn in a staggered manner.
[0011] Preferably, both the main code track coil and the vernier code track coil include four sine waves.
[0012] Preferably, the radial height difference between the main code track coil and the vernier code track coil is greater than or equal to 1 mm.
[0013] Preferably, the main code channel coil includes 32 signal cycle coils.
[0014] Preferably, the vernier track coil includes one signal cycle coil.
[0015] Compared with the prior art, the linear inductive encoder provided by this utility model reduces the layout area of the receiving coil by overlapping the main code track coil and the vernier code track coil, thereby realizing the miniaturization of the coil board of the inductive encoder. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of a conventional stator in one embodiment of this utility model.
[0017] Figure 2 This is a schematic diagram of the stator according to an embodiment of the present invention.
[0018] Figure 3 This is a schematic diagram of the moving part of an embodiment of the present invention. Detailed Implementation
[0019] To address the issue of the main code track coil and vernier code track coil being drawn side-by-side in an absolute linear displacement encoder, which significantly increases the board area for both coils, this invention provides a linear inductive encoder comprising: a mover and a stator. The mover includes a second PCB substrate and multiple copper foils disposed on the substrate; the stator includes a first PCB substrate, multiple excitation coils and receiving coils disposed on the first PCB substrate.
[0020] refer to Figure 2The first PCB substrate 1 has 6 layers. On the first layer of the first PCB substrate 1, two rectangular coils of excitation coil 2 are drawn in a counterclockwise direction. A via (not shown in the figure) is made at the end of the first layer excitation coil 2. Move to the second layer and draw two rectangular coils in a counterclockwise direction, overlapping with the traces of the excitation coil 2 on the first layer. After completing the drawing of the second layer excitation coil 2, a via (not shown in the figure) is made at the end of the second layer excitation coil 2. Move to the third layer and draw two rectangular coils in a counterclockwise direction with overlapping traces. A via (not shown in the figure) is made at the end of the third layer excitation coil 2. Move to the fourth layer and draw two rectangular coils in a counterclockwise direction with the same overlapping traces. The drawing of the fourth layer excitation coil 2 is completed. The line width and line spacing of the excitation coil 2 are kept consistent.
[0021] The receiving coil 3 includes a main code track coil 301 and a vernier code track coil 302 drawn in staggered and overlapping layers on the first PCB substrate 1. Both the main code track coil 301 and the vernier code track coil 302 include four sine wave coils. Each sine wave coil is drawn in staggered and overlapping layers, and the sine wave coil changes layers every half cycle.
[0022] Each sinusoidal waveform coil of the main code track coil 301 has a radial length of 10mm and includes four 32-cycle signal cycle coils, specifically sinusoidal waveform coils. The specific drawing method is as follows: On the first layer of the main code track coil 301 of the first PCB substrate 1, the first sinusoidal waveform coil is drawn starting from 0° within the rectangular induction area formed by the excitation coil 2. A via is placed at the peak of the sinusoidal waveform coil trace (not shown in the figure). The next trace is drawn on the second layer, and a via is placed at the trough (not shown in the figure). The remaining sinusoidal waveform trace is drawn on the first layer, thus completing one cycle of the coil. The remaining 31 cycles of the coil are then completed in the same way, and a via is placed at the end point (not shown in the figure). The second sine wave coil is drawn starting from the second layer of the first PCB substrate 1. Its starting point coincides with the starting point of the first sine wave coil, but the phase difference is 180°. The sine wave coil is drawn starting from the second layer of the first PCB substrate 1. A via (not shown in the figure) is placed at the trough to draw the next trace on the first layer. Another via (not shown in the figure) is placed at the crest to draw the remaining sine wave trace on the second layer. This completes one cycle of the signal. The remaining 31 cycles of the coil are then drawn in the same way. The third sine wave coil is drawn in the same way as the first sine wave coil, except that the phase difference at the starting point is 90°. The fourth sine wave coil is drawn in the same way as the second sine wave coil, except that the phase difference at the starting point is 90°.
[0023] Each sinusoidal waveform coil of the vernier track coil 302 has a radial length of 8.9 mm and includes four 1-cycle signal cycle coils, specifically sinusoidal waveform coils. The specific drawing method is as follows: On the third layer of the first PCB substrate 1, the first sinusoidal waveform coil of the vernier track coil 302 is drawn starting from 45° within the rectangular induction area formed by the excitation coil 2. A via is placed at the peak of the sinusoidal waveform coil trace (not shown in the figure). The next trace is drawn on the fourth layer, and a via is placed at the trough (not shown in the figure). The remaining sinusoidal waveform traces are drawn on the third layer, thus completing one cycle of the coil. The coil width is and a via is placed at the end point (not shown in the figure). The second sine wave coil is drawn starting from the fourth layer of the first PCB substrate 1. Its starting point coincides with the starting point of the first sine wave coil, but the phase difference is 180°. The sine wave coil is drawn starting from the fourth layer of the first PCB substrate 1. A via (not shown in the figure) is placed at the trough. The next trace is drawn on the first layer. Another via (not shown in the figure) is placed at the crest. The remaining sine wave trace is drawn on the second layer. This completes the drawing of the sine wave coil for one vernier track. The third sine wave coil is drawn in the same way as the first sine wave coil, except that the phase difference at the starting point is 90°. The fourth sine wave coil is drawn in the same way as the second sine wave coil, except that the phase difference at the starting point is 90°.
[0024] refer to Figure 3 The second PCB substrate 4 has 7 copper foils 5 with equal spacing. Each copper foil 5 and the next copper foil 5 form a cycle line. Within the width of a cycle line, the width of the copper foil 5 accounts for 50% of the total width. A total of 7 cycle lines are set.
[0025] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.
Claims
1. A linear inductive encoder, comprising: The mover and stator are characterized in that, The stator includes a first PCB substrate, a plurality of excitation coils and a receiving coil disposed on the first PCB substrate, wherein... The first PCB substrate is a multilayer board; The multiple excitation coils are drawn in staggered layers and electrically connected through vias; The receiving coil includes a main code track coil and a vernier code track coil; The main code track coil and the vernier code track coil are drawn in a staggered and overlapping manner; The mover includes a second PCB substrate and a plurality of copper foils disposed on the substrate, wherein the copper foils are arranged at equal intervals on the second PCB substrate to form periodic etched lines.
2. A linear inductive encoder according to claim 1, characterized in that, Each graduation of the periodic scale consists of 50% copper foil and 50% substrate.
3. A linear inductive encoder according to claim 1, characterized in that, The first PCB substrate is a six-layer board.
4. A linear inductive encoder according to claim 1, characterized in that, The excitation coil is a two-turn rectangular coil.
5. A linear inductive encoder according to claim 1, characterized in that, The excitation coils are drawn in a counterclockwise direction between different first PCB substrate layers, and the end of the previous excitation coil is connected to the starting point of the next excitation coil through a via.
6. A linear inductive encoder according to claim 1, characterized in that, The receiving coil and the excitation coil are drawn in a staggered manner.
7. A linear inductive encoder according to claim 1, characterized in that, Both the main code track coil and the vernier code track coil include four sinusoidal waveform coils.
8. A linear inductive encoder according to claim 7, characterized in that, The radial height difference between the main code track coil and the vernier code track coil is greater than or equal to 1 mm.
9. A linear inductive encoder according to claim 7, characterized in that, The main code channel coil includes 32 signal cycle coils.
10. A linear inductive encoder according to claim 7, characterized in that, The vernier track coil includes one signal period coil.