阅读说明：本技术 一种缝纫机及缝纫方法 (sewing machine and sewing method ) 是由 范国锋 徐龙姣 于 2018-05-28 设计创作，主要内容包括：本发明属于缝制机械技术领域,涉及一种缝纫机及缝纫方法,其解决了现有锁式线迹线环形成稳定性差等问题。缝纫机包括机头、电机、主轴和针杆,电机和主轴均设置于机头上,电机与主轴相连,主轴与针杆相连,针杆设置有机针,针杆下方有针板,机针由位移最低点移动至针板处为第一行程,同一周期内其它行程为第二行程,第一行程中电机平均转速ω1小于第二行程中电机平均转速ω2。本缝纫方法包括以下步骤：A、启动电机,以平均速度ω2带动机针由上往下朝位移最低点处移动；B、将电机平均速度降为ω1,并带动机针由位移最低点处朝针板移动；C、将电机平均速度升至ω2,带动机针向其位移最高处移动。本发明可有效提高锁式线迹线环形成稳定性。(The invention belongs to the technical field of sewing machinery, relates to a sewing machine and a sewing method, and solves the problems of poor stability of the existing lock stitch loop and the like. The sewing machine comprises a machine head, a motor, a main shaft and a needle rod, wherein the motor and the main shaft are arranged on the machine head, the motor is connected with the main shaft, the main shaft is connected with the needle rod, the needle rod is provided with a needle, a needle plate is arranged below the needle rod, the needle moves to the needle plate from the lowest displacement point to form a first stroke, other strokes in the same period are second strokes, and the average rotating speed omega 1 of the motor in the first stroke is smaller than the average rotating speed omega 2 of the motor in the second stroke. The sewing method comprises the following steps: A. starting a motor, and driving the machine needle to move from top to bottom to the lowest displacement point at the average speed omega 2; B. reducing the average speed of the motor to omega 1 and driving the needle to move towards the needle plate from the lowest displacement point; C. the average speed of the motor is increased to omega 2, and the needle is driven to move to the highest displacement position. The invention can effectively improve the forming stability of the lock stitch loop.)

1. A sewing machine comprises a machine head, a motor (1), a main shaft (2) and a needle bar (3), the motor (1) is fixed on the machine head, the main shaft (2) is rotationally arranged on the machine head, the output end of the motor (1) is connected with the main shaft (2), the main shaft (2) is connected with the needle bar (3) through the transmission mechanism (4), a needle (5) is arranged at the lower end of the needle rod (3), a needle plate (6) for the needle (5) to pass through is arranged below the needle rod (3), the needle bar mechanism is characterized in that the section of stroke of the needle (5) moving from the lowest displacement point to the needle plate (6) is a first stroke, other strokes of the needle (5) in the same period are second strokes, and the average rotating speed omega 1 of the motor (1) in the first stroke is smaller than the average rotating speed omega 2 of the motor (1) in the second stroke.

2. Sewing machine as in claim 1, characterized in that said motor (1) is a servomotor (1).

3. Sewing machine according to claim 1 or 2, characterised in that the magnitude of ω 1 is 1/2 of ω 2.

4. The sewing machine according to claim 1 or 2, characterized in that the transmission mechanism (4) comprises a crank (7) and a connecting rod (8), one end of the crank (7) is connected with the end of the main shaft (2), the other end of the crank (7) is connected with one end of the connecting rod (8), the other end of the connecting rod (8) is hinged on the needle bar (3), a sliding block (9) is fixed on the needle bar (3), and the machine head is provided with a sliding rail (10) matched with the sliding block (9) along the vertical direction.

5. A sewing method using the sewing machine according to claim 1, characterized in that the sewing method comprises the steps of:

A. Placing the cloth on a needle plate (6), starting a motor (1), driving a needle (5) to penetrate through the cloth and the needle plate (6) from top to bottom at an average speed of omega 2, and moving towards the lowest displacement point of the needle plate;

B. Reducing the average speed of the motor (1) to omega 1 and driving the needle (5) to move towards the needle plate (6) from the lowest displacement point;

C. The average speed of the motor (1) is increased to omega 2, and the needle (5) is driven to move to the highest displacement position.

6. Sewing method as in claim 5, characterized in that the motor (1) starts decelerating as soon as the needle (5) reaches its lowest point of displacement, and that the motor (1) starts accelerating as the needle (5) rises back and leaves the needle plate (6).

7. Sewing method as in claim 5, characterized in that when the needle (5) moves from top to bottom close to the cloth, the motor (1) starts to decelerate, and when the lower end of the needle (5) moves back from bottom to top close to the cloth, the motor (1) starts to accelerate.