Sewing machine upper shaft position sensing mechanism

Abstract

The utility model relates to a sewing machine upper shaft position sensing mechanism, including sewing machine frame, set up on the sewing machine frame upper shaft, be provided with upper shaft big connecting rod cam on the upper shaft, be provided with magnet that rotates with upper shaft big connecting rod cam rotation on upper shaft big connecting rod cam, be provided with hall switch on the sewing machine frame, magnet can rotate to with hall switch present opposite position state. The utility model has the beneficial effects of: magnet and hall switch can form opposite position accurate match, reach the state of phase accuracy, realize upper shaft position sensing effect, ensure the accurate triggering of hall switch, thereby realize the effect of accurate needle stop, improve the needle stop precision, reduce the product cost, use effectual, be favorable to the promotion.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, and in particular to a sewing machine upper shaft position sensing mechanism. Background Technology

[0002] Currently, conventional sewing machines on the market operate by rotating the main shaft, which drives the sewing needle bar to reciprocate up and down to perform sewing work. When the sewing machine stops, the sewing needle stops at the corresponding position, which is divided into the upper needle stop position and the lower needle stop position.

[0003] Currently, for conventional sewing machines on the market, the needle-stopping accuracy of sewing machine motors and controllers driven by Hall effect is low (±10 degrees). This accuracy cannot meet the needle-stopping accuracy required by sewing machines with automatic thread trimming function. If higher accuracy is required, expensive servo motors and controllers need to be replaced, which increases product cost. Therefore, there is an urgent need to develop a low-cost, high-precision sewing machine driven by Hall effect.

[0004] Currently, Chinese utility model patent CN202223453653.4 discloses a needle-stop control device for a household sewing machine. This patent discloses a needle-stop control device for a household sewing machine, including a machine housing, a Hall sensor assembly, and a magnet. A handwheel is mounted on the machine housing, and a groove is formed at the end of the machine housing facing the handwheel. The Hall sensor assembly is at least partially located within the groove. A mounting hole is formed on the end face of the handwheel facing the machine housing, and the magnet is embedded in the mounting hole. The handwheel can rotate to bring the magnet into contact with the Hall sensor assembly. Regarding the setup, this structure, because the magnet is located on the handwheel, has the following drawbacks: Sewing machines have two working states: normal sewing and bobbin winding. During normal sewing, the handwheel and main shaft are tightly engaged, maintaining a fixed relative position. When switching to bobbin winding mode, the handwheel disengages from the main shaft, and their relative position is no longer fixed. When switching back to sewing mode, the handwheel and main shaft engage again, but the relative position deviates, causing errors in position sensing and consequently, errors in needle stopping position. This results in reduced needle stopping accuracy, failing to meet the required usage. Utility Model Content

[0005] This invention provides a sewing machine upper shaft position sensing mechanism, which can achieve precise needle stopping effect, improve needle stopping accuracy, and reduce product cost.

[0006] This utility model provides a sewing machine upper shaft position sensing mechanism, including a sewing machine frame, an upper shaft mounted on the sewing machine frame, an upper shaft connecting rod cam mounted on the upper shaft, a magnet mounted on the upper shaft connecting rod cam that rotates with the rotation of the upper shaft connecting rod cam, a Hall switch mounted on the sewing machine frame, and the magnet being rotatable to a position relative to the Hall switch.

[0007] Furthermore, a mounting bracket is provided above the upper shaft, and the mounting bracket is set on the sewing machine frame, with the Hall switch mounted on the mounting bracket.

[0008] Furthermore, bolts are provided on the mounting bracket, and the Hall switch is fixed to the mounting bracket by the bolts.

[0009] Furthermore, the upper shaft connecting rod cam has a mounting hole facing the Hall switch position, and the magnet is placed inside the mounting hole.

[0010] Furthermore, the upper shaft connecting rod cam is a one-piece molded upper shaft connecting rod cam.

[0011] Furthermore, the upper connecting rod cam is made of plastic material.

[0012] Furthermore, the magnets are arranged in a cylindrical shape.

[0013] The beneficial effects of this utility model are as follows: The sewing machine upper shaft position sensing mechanism of this utility model, by setting a magnet on the upper shaft connecting rod cam, allows the magnet to rotate with the upper shaft connecting rod cam, so that the magnet and the Hall switch are precisely matched in relative position through this rotation, achieving a state of precise phase, realizing the upper shaft position sensing effect, ensuring the accurate triggering of the Hall switch, thereby achieving the effect of precise needle stopping, improving needle stopping accuracy, reducing product cost, having good use effect, and being conducive to promotion. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model; Figure 2 This is a schematic diagram showing the positional states of the magnet and the Hall switch in an embodiment of the present invention; Figure 3 This is a schematic diagram of the explosion state of the magnet and Hall switch in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of this utility model applied to a sewing machine.

[0015] Explanation of reference numerals in the attached drawings: 1. Sewing machine frame; 2. Upper shaft; 3. Upper shaft connecting rod cam; 4. Magnet; 5. Hall switch; 6. Mounting bracket; 7. Bolt; 8. Mounting hole. Detailed Implementation

[0016] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0017] As shown in the figure, the sewing machine upper shaft position sensing mechanism of this utility model embodiment includes a sewing machine frame 1, an upper shaft 2 mounted on the sewing machine frame 1, and an upper shaft connecting rod cam 3 mounted on the upper shaft 2. The rotation of the upper shaft 2 drives the upper shaft connecting rod cam 3 to rotate, which in turn drives the sewing machine needle bar to reciprocate up and down, thus achieving sewing work. Therefore, during operation, when the upper shaft 2 rotates, the upper shaft connecting rod cam 3 rotates simultaneously with the upper shaft 2. A magnet 4 is mounted on the upper shaft connecting rod cam 3 and rotates simultaneously with it. A Hall switch 5 is mounted on the sewing machine frame 1 and is fixed in position. The magnet 4 can rotate to a position opposite to the Hall switch 5. That is, when the upper shaft connecting rod cam 3 rotates, it drives the magnet 4 to rotate simultaneously, causing the magnet 4 to rotate to a position opposite to the Hall switch 5. In other words, when sewing... When the machine needs to stop, the upper shaft connecting rod cam 3 rotates, causing magnet 4 to match the relative position of Hall switch 5. Hall switch 5 generates a signal corresponding to the position of the magnet and sends it to the controller. The controller controls the sewing machine motor to stop working, realizing the needle stop at the upper stop position. Since magnet 4 matches the relative position of Hall switch 5 with the rotation of upper shaft connecting rod cam 3, Hall switch 5 can be accurately triggered, thus achieving the effect of precise relative position correspondence. This allows for precise needle stop at the upper stop position without manual operation, achieving the effect of precise relative position matching. It can automatically complete the precise needle stop at the upper stop position, improving needle stop accuracy. There is no need to replace the expensive servo motor and corresponding controller. The sewing machine driven by Hall effect achieves high precision and low cost. Furthermore, precise needle stop can avoid thread take-up errors, reduce operational errors, and improve work efficiency. It realizes the effect of upper shaft 2 position sensing. The controller and motor are existing technologies in sewing machines and will not be described in detail.

[0018] A mounting bracket 6 is provided above the upper shaft 2. The mounting bracket 6 is set on the sewing machine frame 1. The Hall switch 5 is set on the mounting bracket 6. The mounting bracket 6 is used to fix the position of the Hall switch 5, so that the position of the Hall switch 5 is fixed and the Hall switch 5 is in a static position, ensuring the accurate triggering of the Hall switch 5.

[0019] The mounting bracket 6 is equipped with bolts 7, and the Hall switch 5 is fixed to the mounting bracket 6 by the bolts 7. The use of bolts 7 can stably fix the Hall switch 5 to the mounting bracket 6, which can further increase the position fixation effect of the Hall switch 5.

[0020] The upper shaft connecting rod cam 3 has a mounting hole 8 facing the Hall switch 5. The magnet 4 is placed in the mounting hole 8. The mounting hole 8 is used to install the magnet 4, and the magnet 4 and the mounting hole 8 form an interference fit to ensure that the magnet 4 remains stable when rotating and to ensure the normal operation of the magnet 4. Furthermore, the magnet 4 is directly installed on the upper shaft connecting rod cam 3 through the mounting hole 8 without the need for other structures to install the magnet 4. On the one hand, it saves space and facilitates the installation of parts. On the other hand, it reduces the installation structure, saves costs, and reduces production costs.

[0021] The upper shaft connecting rod cam 3 is a one-piece molded upper shaft connecting rod cam 3. This configuration, with the upper shaft connecting rod cam 3 being a one-piece molded cam, means that the mounting hole 8 is also a one-piece molded cam. On the one hand, the one-piece molding ensures the stable installation of the magnet 4 and the working stability of the magnet 4. On the other hand, it eliminates the need for additional hole-making processes, reducing the number of production steps in the sewing machine and lowering production costs.

[0022] The upper shaft connecting rod cam 3 is made of plastic material. The plastic material used in the upper shaft connecting rod cam 3 results in low cost and facilitates one-piece molding, reducing production costs.

[0023] Magnet 4 is set in a cylindrical shape. The cylindrical shape of magnet 4 ensures the sensing effect and makes installation easy; simply press it down to install the magnet 4.

[0024] When the sewing machine needs to stop, the upper shaft connecting rod cam 3 rotates, driving the magnet 4 to match the relative position of the Hall switch 5. The Hall switch 5 generates a signal corresponding to the position of the magnet and sends it to the controller. The controller controls the sewing machine motor to stop working, realizing the needle stop at the upper stop position and completing the precise needle stop process.

[0025] The features of this utility model embodiment are as follows: The sewing machine upper shaft position sensing mechanism of this utility model sets a magnet on the upper shaft connecting rod cam, so that the magnet can rotate with the upper shaft connecting rod cam. This rotation method allows the magnet to form a precise relative position match with the Hall switch, achieving a precise phase state, ensuring accurate triggering of the Hall switch, thereby achieving a precise needle stop effect, improving needle stop accuracy, reducing product cost, having good performance, and being easy to promote.

[0026] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A sewing machine upper shaft position sensing mechanism, comprising a sewing machine frame (1) and an upper shaft (2) disposed on the sewing machine frame (1), characterized in that: The upper shaft (2) is provided with an upper shaft connecting rod cam (3), and the upper shaft connecting rod cam (3) is provided with a magnet (4) that rotates with the upper shaft connecting rod cam (3). The sewing machine frame (1) is provided with a Hall switch (5), and the magnet (4) can rotate to a position relative to the Hall switch (5).

2. The sewing machine upper shaft position sensing mechanism according to claim 1, characterized in that: A mounting bracket (6) is provided above the upper shaft (2), the mounting bracket (6) is provided on the sewing machine frame (1), and the Hall switch (5) is provided on the mounting bracket (6).

3. The sewing machine upper shaft position sensing mechanism according to claim 2, characterized in that: The mounting bracket (6) is provided with bolts (7), and the Hall switch (5) is fixed to the mounting bracket (6) by bolts (7).

4. The sewing machine upper shaft position sensing mechanism according to claim 1, characterized in that: The upper shaft connecting rod cam (3) has a mounting hole (8) facing the position of the Hall switch (5), and the magnet (4) is disposed in the mounting hole (8).

5. The sewing machine upper shaft position sensing mechanism according to claim 1, characterized in that: The upper shaft connecting rod cam (3) is an integrally formed upper shaft connecting rod cam (3).

6. The sewing machine upper shaft position sensing mechanism according to claim 5, characterized in that: The upper shaft connecting rod cam (3) is made of plastic material.

7. The sewing machine upper shaft position sensing mechanism according to claim 1, characterized in that: The magnet (4) is arranged in a cylindrical shape.

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