Cutting mechanism and cutting method of numerical control spring coiling machine

Abstract

The invention provides a numerical control spring coiling machine cut-off mechanism which comprises a cut-off mechanism body controlled by a numerical control system, the cut-off mechanism body comprises an X-direction driving mechanism, a Z-direction driving mechanism, a connecting rod and a laser cutting head, the X-direction driving mechanism drives the Z-direction driving mechanism to move in the X direction, and the Z-direction driving mechanism comprises a connecting table moving in the Z direction; a pair of connecting rods with the same length are arranged in parallel, the two ends of each connecting rod are rotationally fixed to the connecting table and the laser cutting head respectively to form a parallelogram mechanism, the connecting table is provided with a limiting table, and the limiting table is supported on the lower side faces of the connecting rods. By adopting the cutting mechanism, two cutting modes can be quickly switched, the mechanical structure and control are simplified, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of numerical control spring coiling machines, and in particular to a cutting mechanism and a cutting method of a numerical control spring coiling machine. Background Art

[0002] As an important basic component in industrial production, springs are widely used in the fields of automobiles, ships, aerospace, etc. With the development of industry, the demand for springs with high precision, high strength and good stability is becoming more and more urgent, and the demand is also increasing. This puts higher requirements on the performance and efficiency of spring coiling machines, especially their cutting methods and cutting efficiency.

[0003] After the spring "winding" process is completed, the spring must be cut off from the last circle of the spring body. The existing CNC spring winding machines use straight cutting, swing cutting, half cutting or twisting cutting methods to cut the spring, all of which are mechanical cutting. Mechanical cutting has a large extrusion stress on the cutting edge of the tool, and the tool is prone to frequent damage and replacement after long-term use. Especially for oil-quenched spring steel wire and high-strength spring steel wire, the mechanical cutting mechanism requires a large force to cut the spring, and the mechanical cutting mechanism is prone to damage after long-term work, and its trouble-free operation time is short. Frequent replacement of tools and cutting mechanisms brings about the problems of high overall cost and low production efficiency. Mechanical cutting also has the problem of "hook" phenomenon caused by deformation of the spring end and deformation of the first circle of the spring, which affects the forming accuracy and batch stability of the spring. The above problems have become bottlenecks restricting the processing of the spring manufacturing industry and need to be solved urgently.

[0004] It is necessary to develop a cutting mechanism and a cutting method for a CNC spring coiling machine to solve the above problems. Summary of the invention

[0005] In view of the defects in the prior art, the present invention aims to provide a cutting mechanism and method for a CNC spring coiling machine.

[0006] The technical solution to realize the present invention is: after the spring winding process is completed, the cutting mechanism is started by the spring coiling machine numerical control system, the numerical control system drives the laser cutting head to focus on the position of the spring steel wire to be cut, triggers the laser to work, and at the same time the cutting mechanism drives the laser cutting head to move, completing the plane cutting of the spring end face or the cross-section cutting of the spring steel wire. It is especially applicable to springs of different diameters.

[0007] The cutting mechanism of the CNC spring coiling machine is used to cut the spiral spring formed by the spring coiling machine, and includes a CNC system for controlling the operation of the cutting mechanism. The cutting mechanism includes an X-direction drive mechanism, a Z-direction drive mechanism, a connecting rod and a laser cutting head. The X-direction drive mechanism is fixedly installed on the spring coiling machine, and the X-direction drive mechanism includes a slider moving along the X-direction. The Z-direction drive mechanism is fixedly connected to the slider. The Z-direction drive mechanism includes a connecting table moving along the Z-direction. A pair of connecting rods of equal length are arranged parallel to each other, and the two ends are rotatably mounted on the connecting table and the laser cutting head, respectively, to form a parallelogram mechanism. Limiting tables are arranged on the upper and lower sides of the connecting table, and the limiting table is supported on the lower side of the connecting rod by the gravity of the laser cutting head. The laser cutting head is limited to move downward. To avoid interference, the limiting table is an inclined surface, and the inclined surface is supported on the lower side of the connecting rod.

[0008] To control the accuracy, both the X-direction drive mechanism and the Z-direction drive mechanism use servo motors connected to the ball screw pair through a coupling. The screw pair of the X-direction drive mechanism drives the slider to move in the X direction, and the screw pair of the Z-direction drive mechanism drives the connecting table to move in the Z direction.

[0009] In order to achieve cross-section cutting, a stopper is fixedly provided below the Z-direction driving mechanism, and a guide block parallel to the stopper and extending relatively along the Y-direction is provided below the connecting rod on the laser cutting head, thereby realizing L-shaped movement of the laser cutting head, simplifying the mechanical structure and control, and being able to realize two cutting methods at the same time.

[0010] The present invention also provides a cutting method of a numerically controlled spring coiling machine, which is used to realize the two cutting modes of the spring.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. The laser cutting mechanism is simple. The Z-axis driving mechanism is connected to the laser head through a connecting rod to realize the L-shaped movement of the laser cutting head, which simplifies the mechanical structure and control;

[0013] 2. Two cutting methods can be realized for springs: plane cutting of the spring end face and cutting of the spring steel wire. The cut surface is smooth, the outer diameter of the spring changes little after cutting, and no mechanical deformation occurs during cutting. It has high precision and good stability, and reduces the spring grinding equipment and processes.

[0014] 3. The laser cutting method is simple. The laser cutting mechanism can be started after the spring is wound. There is no need to wait, and the cutting efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of a CNC laser cutting spring coiling machine;

[0016] Figure 2 This is the front view of the laser cutting mechanism;

[0017] Figure 3 It is the left view of the laser cutting mechanism;

[0018] Figure 4 This is an enlarged diagram of the two spring schematics;

[0019] Figure 5 It is a schematic diagram of the X-axis driving mechanism;

[0020] Figure 6 Schematic diagram of the Z-axis drive mechanism.

[0021] The figure shows:

[0022] 1. Spring steel wire; 2. Feeding mechanism; 3. Wire feeding slot plate; 4. Pitch knife; 5. Cutting mechanism; 6. Variable diameter mechanism; 7. Spring; 51. X-axis driving mechanism; 52. Z-axis driving mechanism; 53. Connecting rod; 54. Laser cutting head; 55. Stopper; 56. Guide block; 511 / 521. Servo motor; 512 / 522. Coupling; 513 / 523. Ball screw pair; 514. Slider; 524. Connecting table; 525. Limiting table; 71. End surface smoothing spring; 711. End surface; 72. Spring cross section cutting spring; 721. Cross section. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, without departing from the inventive concept, several changes and improvements can also be made, which all belong to the protection scope of the present invention.

[0024] For the convenience of understanding and describing the present invention, the feeding direction is defined as the X direction, the spring extension direction is defined as the Y direction, and the direction perpendicular to the X direction and the Y direction is defined as the Z direction.

[0025] like Figures 1 to 6 As shown, the spring coiling machine includes a feeding mechanism 2, a diameter reducing mechanism 6, a cutting mechanism 5 and a numerical control system. The spring wire 1 is transported to the X direction through the roller on the feeding mechanism 2, and reaches the diameter reducing mechanism 6 through the wire feeding slot plate 3 at the end of the feeding mechanism. Under the resistance of the diameter reducing mechanism 6, the spring wire undergoes plastic deformation to form a spring coil of a circular spring. The feeding mechanism 2 feeds continuously, and a spring 7 is rolled out under the coordinated action of the diameter reducing mechanism 6 and the pitch knife 4. The extension direction of the spring 7 is perpendicular to the feeding direction. When the spring is rolled for the last circle, the cutting mechanism 5 is started by the numerical control system to cut it off, forming a complete spring 7. The numerical control system controls each system to make the next spring.

[0026] This embodiment provides a CNC spring coiling machine cutting mechanism for cutting the spring 7 to form a spring 71 with a flat end surface. The entire surface of the spring end surface 711 is perpendicular to the extension direction of the spring, that is, the end surface 711 of the spring 7 is parallel to the XZ plane.

[0027] The cutting mechanism 5 includes an X-direction drive mechanism 51, a Z-direction drive mechanism 52, a connecting rod 53 and a laser cutting head 54. The X-direction drive mechanism 51 includes a servo motor 511, a coupling 512, a ball screw pair 513 and a slider 514 fixed on the spring coiling machine. The servo motor 511 is fixedly installed on the spring coiling machine. The ball screw pair 513 is connected to the servo motor 511 through the coupling 512. The ball screw pair 513 can drive the slider to move back and forth along the X direction. The Z-direction drive mechanism 52 is perpendicular to the X-direction drive mechanism 51 and is fixed on the slider 514. The slider 514 of the X-direction drive mechanism 51 drives the Z-direction drive to move back and forth along the X direction. The Z-direction drive mechanism 52 includes a servo motor 521, a coupling 522, a ball screw pair 523 and a connecting platform 524. The servo motor 521 is fixedly mounted on the slider 514, and the ball screw pair 523 is connected to the servo motor 521 through the coupling 522. The ball screw pair 523 can drive the connecting platform 524 to move back and forth along the Z direction. The laser cutting head 54 is arranged parallel to the Z-direction driving mechanism 52. The connecting platform 524 and the laser cutting head 54 are both provided with a mounting surface on the YZ surface. The two ends of a pair of connecting rods 53 of the same length are rotatably mounted on the mounting surfaces of the laser cutting head 54 and the connecting platform 524. The two connecting rods are arranged parallel to each other, forming a parallelogram mechanism with the laser cutting head and the connecting platform. The laser cutting head can rotate around the X axis relative to the connecting platform. The connecting platform 524 is provided with a limit platform 525, and the limit platform 525 is located on the lower side of one of the connecting rods or the two connecting rods. Under the action of gravity, the laser cutting head supports the limit platform on the lower side of the connecting rod. To prevent interference, the limit platform 525 is an inclined surface, which is a surface of the XY plane rotating downward along the X-axis. When the connecting rod 53 rotates to a low position under the action of gravity, the limit platform inclined surface supports the lower side of the connecting rod, limiting the connecting rod from continuing to rotate downward.

[0028] In this embodiment, the method for cutting the end face 711 of the spring 71 with a flat end face is as follows: When the spring steel wire 1 is transported in the X direction by the roller on the feeding mechanism 2, it reaches the diameter-changing mechanism 6 through the wire feeding slot plate 3 at the end of the feeding mechanism. Under the resistance of the diameter-changing mechanism 6, the spring steel wire undergoes plastic deformation to form a spring coil. The feeding mechanism 2 continuously feeds, and a spring 7 is rolled out under the coordinated action of the diameter-changing mechanism 6 and the pitch knife 4. When the spring is rolled for the last circle, the numerical control system controls the start of the cutting mechanism 5. The cutting mechanism 5 first causes the X-direction drive mechanism 51 to drive the Z-direction drive mechanism 52 to reach the outside of the specified position of the spring. Specifically, the servo motor 511 rotates the ball screw pair 513 through the coupling 512, so that the Z-direction drive mechanism 52 moves along the X direction to the outside of the specified position of the spring under the guidance of the slider 514, that is, Figure 3 The spring winding starting side shown. Secondly, the Z-direction driving mechanism 52 drives the laser cutting head 54 to move downward to the surface of the spring steel wire to be cut and focus the laser. Specifically, the servo motor 521 rotates the ball screw pair 523 through the coupling 522, drives the connecting table 524 to move along the Z direction, and drives the laser cutting head 54 to move along the Z direction to the surface of the spring steel wire to be cut and focus through the connecting rod 53. Finally, the laser is started for laser cutting. During the cutting process, the X-direction driving mechanism 51 and the Z-direction driving mechanism 52 are controlled by the numerical control system to work together, so that the laser cutting head 54 performs X-direction and Z-direction interpolation movements, so that the laser cutting head 54 is always focused on the surface of the spring steel wire until the entire end face 711 of the end face flattened spring 71 is cut. During this cutting process, due to the gravity of the laser cutting head 54, the lower side of the connecting rod 53 always rests on the limit table 525. After cutting, the laser is turned off, the laser cutting mechanism is reset, and the next spring is processed. The cutting process uses oxygen, nitrogen or high-pressure air as high-pressure cooling medium, and the filter cartridge dust collector can collect the waste formed by laser cutting in time. The above process can adjust the diameter-changing mechanism 6 to change the diameter of the spring as needed, and adjust the program to complete the cutting of the end faces of springs with different diameters.

[0029] The second embodiment provides a cutting mechanism of a numerically controlled spring coiling machine for cutting a spring 7 to form a spring cross section cut spring 72 , wherein the spring cross section 721 is a vertical cross section of the spring.

[0030] This embodiment has the same structure as the first embodiment in that the X-direction drive mechanism 51, the Z-direction drive mechanism 52, the connecting rod 53 and the laser cutting head are also provided. The stopper 55 is horizontally arranged below the Z-direction drive mechanism 52, and one end is fixed on the housing of the Z-direction drive mechanism 52. The guide block 56 is fixedly mounted on the laser cutting head, located below the connecting rod, parallel to the stopper 55 and relatively extending in the Y direction, so that when the connecting rod 53 rotates, the laser cutting head 54 is stable and the motion trajectory is controllable. The stopper 55 is provided with a guide groove on the surface on the side opposite to the guide block 56. The width of the guide groove in the X direction matches the width of the guide block 56 in the X direction. The guide groove limits the shaking of the guide block in the X direction. When the Z-direction drive mechanism 52 moves downward to make the guide block 56 enter the guide groove, the Z-direction drive mechanism 52 continues to move downward, and the stopper 55 slides along the guide groove in the Y direction, driving the laser cutting head to move in the Y direction. Only the Z-direction drive mechanism moves to realize the L-shaped movement of the laser cutting head.

[0031] The specific cutting method is as follows: the same coiled spring as in the first embodiment is used, and the laser cutting mechanism 5 is started by the numerical control system when the spring is coiled for the last turn. The cutting mechanism 5 firstly makes the X-direction drive mechanism 51 drive the Z-direction drive mechanism 52 to reach the outside of the specified position of the spring, specifically, the servo motor 511 rotates the ball screw pair 513 through the coupling 512, so that the Z-direction drive mechanism 52 moves along the X direction to above the specified position of the spring under the guidance of the slider 514. Secondly, the Z-direction drive mechanism 52 drives the laser cutting head 54 to move downward along the Z direction. When the guide block 56 fixed on the laser cutting head 54 contacts the stopper 55 fixed on the Z-direction drive mechanism 52, the stopper 56X is inserted into the guide groove on both sides. At this time, the laser output by the laser cutting head has been adjusted in advance to focus on the steel wire to be cut. Finally, the laser is started, and the Z-direction driving mechanism 52 continues to work to make the connecting platform 524 move downward in the Z direction. The laser cutting head 54 stops moving in the Z direction because the guide block 56 is restricted by the stopper 55, and the guide block 56 starts to slide in the Y direction along the guide groove on the guide block 56. The connecting rod 53 rotates to drive the laser cutting head to move in the Y direction until the spring wire section is cut. After cutting, the laser is turned off and the laser cutting mechanism is reset to start processing the next spring.

[0032] The cutting process uses oxygen, nitrogen or high-pressure air as high-pressure cooling medium, and the filter cartridge dust collector can collect the waste formed by laser cutting in time. The above process can adjust the diameter of the spring by adjusting the diameter-changing mechanism 6 as needed, and adjust the program to complete the cutting of spring sections with different diameters.

Claims

1. A cutting mechanism of a CNC spring coiling machine, used for cutting a coil spring formed by a spring coiling machine, comprising a CNC system for controlling the operation of the cutting mechanism, characterized in that: The cutting mechanism includes an X-direction driving mechanism, a Z-direction driving mechanism, a connecting rod and a laser cutting head. The X-direction driving mechanism is fixedly installed on the spring winding machine. The X-direction driving mechanism includes a slider moving along the X-direction. The Z-direction driving mechanism is fixedly connected to the slider. The Z-direction driving mechanism includes a connecting table moving along the Z-direction. A pair of connecting rods of equal length are arranged parallel to each other, and both ends are rotatably installed on the mounting surfaces of the connecting table and the laser cutting head to form a parallelogram mechanism. The connecting table is provided with a limiting table, and the limiting table is supported on the lower side of the connecting rod.

2. The cutting mechanism of the CNC spring coiling machine according to claim 1, characterized in that: The limiting platform is an inclined surface.

3. The cutting mechanism of the CNC spring coiling machine according to claim 2, characterized in that: The X-direction driving mechanism includes a servo motor, a coupling and a ball screw pair. The servo motor is connected to the ball screw pair through a coupling. The ball screw pair drives the slider to move back and forth along the X direction. The Z-direction driving mechanism includes a servo motor, a coupling and a ball screw pair. The servo motor is connected to the ball screw pair through a coupling. The ball screw pair drives the connecting platform to move along the Z direction.

4. The cutting mechanism of the CNC spring coiling machine according to claim 3, characterized in that: It also includes a stopper and a guide block. The stopper is horizontally arranged below the Z-direction driving mechanism and one end is fixed to the housing of the Z-direction driving mechanism. The guide block is fixedly installed on the laser cutting head and is located below the connecting rod. The stopper and the guide block are parallel to each other and extend relatively along the Y direction.

5. The cutting mechanism of the CNC spring coiling machine according to claim 4, characterized in that: A guide groove is arranged on a side surface of the stopper opposite to the guide block, and the width of the guide groove in the X direction matches the width of the guide block in the X direction.

6. The cutting mechanism of the CNC spring coiling machine according to claim 5, characterized in that: It also includes a feeding mechanism for conveying the spring steel wire along the conveying direction, a diameter-changing mechanism located at the end of the feeding mechanism for winding the spring steel wire into a spiral spring coil, and a cutting mechanism for cutting the spring coil to form a coiled spring. The numerical control system controls the operation of the feeding mechanism, the diameter-changing mechanism and the cutting mechanism.

7. A cutting method for a CNC spring coiling machine, used for cutting a spring so that its end surface is perpendicular to the extension direction of the spring, characterized in that: Cutting is performed using the cutting mechanism of the CNC spring coiling machine as described in any one of claims 1 to 6. When the spring is wound for the last turn, the CNC system starts the cutting mechanism, so that the X-axis drive mechanism drives the Z-axis drive mechanism to reach the outside of the specified position of the spring. Then, the Z-axis drive mechanism drives the laser cutting head to move downward to the surface of the spring wire to be cut and focus. Then the laser is started for cutting, and the CNC system controls the X-axis drive mechanism and the Z-axis drive mechanism to perform interpolation movement, so that the laser cutting head is always focused on the surface to be cut until the cutting is completed and the cutting mechanism is reset.

8. A cutting method of a CNC spring coiling machine, used for cutting a spring so that its spring cross section is the cross section of the end of a spring steel wire, characterized in that: Cutting is performed using the cutting mechanism of the CNC spring coiling machine as described in any one of claims 4 to 5. When the spring is wound for the last turn, the CNC system starts the cutting mechanism, so that the X-axis drive mechanism drives the Z-axis drive mechanism to reach the outside of the specified position of the spring, and then the Z-axis drive mechanism drives the laser cutting head to move downward, and the guide block drives the laser cutting head to slide along the stopper Y direction to the steel wire to be cut until the cutting mechanism is reset after cutting.

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