A production process for a constant force coil spring and a multi-segment constant force coil spring

Abstract

The present invention provides a production process for a constant-force coil spring and a multi-segment constant-force coil spring. The production process includes the following steps: S1. Blank preparation; S2. Cold rolling forming of the spring to obtain a preliminary finished spring; S3. Heat treatment. The cold rolling forming of the spring includes: Step S21. Along the unfolding direction of the constant-force coil spring, the blank is divided into n segments; Step S22. When rolling the blank, the curvatures of the dies for rolling the n segments are different, so that the spring stresses provided on the n segments are different. By dividing the constant-force coil spring into several segments with different curvatures during cold rolling for each segment, that is, different segments of the constant-force spring are rolled with pressing films having different arc radii (curvature radii). After rolling, the spring force provided by the constant-force spring within the same segment remains unchanged, while in the unfolding direction, the spring forces provided by the constant-force springs on different segments are different, thereby meeting the requirements of different support forces; when used as a screen support force source, the same constant-force spring can be used for the support devices of multiple specifications of displays with different weights.

Description

Technical Field

[0001] The present invention relates to the technical field of coil springs for displays, and in particular to a production process for constant-force coil springs. Background Art

[0002] In order to enable the position of the display to be quickly adjusted according to different users, including the position and height at which the display is placed, to suit the viewing needs, the display needs to be supported by a matching lifting device. The quality of the lifting device directly affects the quality of the whole machine. A reasonable lifting device can not only provide better and more comfortable usage conditions for users, but also minimize the size and save space to the greatest extent.

[0003] At present, there are many adjustable constant-force lifting devices on the market. They adopt a draw-out structure and use an internal constant-force spring (also known as a constant-force coil spring or a constant-force spring) to support the weight of the display. With the rapid development of display technology, the manufacturing cost of displays is getting lower and lower. At the same time, users' requirements for the size of displays are becoming more and more large-scale, that is, the sizes of popular or main products on the market are getting larger and larger. Therefore, it is required that the elastic support components of the display support components have greater supporting force.

[0004] In the prior art, the rail-type adjustable constant-force lifting device usually uses a constant-force spring as a supporting force providing component to support the upper display. The constant-force spring, also known as a constant-force spring, is a special type of extension spring at present, also known as a scroll spring. It is evolved from another similar flat scroll spring, also known as a clock spring (the difference between it and the scroll spring is that the coils of its scroll part do not stick to each other). The constant-force scroll spring includes a scroll part formed by winding a long thin metal elastic sheet with an equal outer width into multiple turns and each turn sticking to each other, and having a generally hollow cylindrical shape, and a stretching end extending from the outermost metal sheet of the scroll part. It is mainly used in various balance devices requiring constant-force output, such as lifting balance devices, motor carbon brush springs, etc. Its characteristic is that the spring tension output is relatively constant and the change in tension is extremely small. In actual use, the constant-force spring is directly stretched to make a linear displacement movement, so that the constant-force spring outputs a constant thrust.

[0005] The weights of displays from different manufacturers and of different specifications are different. Therefore, it is necessary to manufacture adjustable constant-force lifting devices with different constant thrusts for support. That is, the same adjustable constant-force lifting device cannot meet the requirements of lifting and adjusting displays of different specifications. As a result, the universality between different displays is poor, which increases the production cost. When replacing the display, it is necessary to replace its support device at the same time, which causes a certain amount of energy waste. Summary of the Invention

[0006] The object of the present invention is to provide a production process for a constant-force coil spring, so as to solve the technical problem in the prior art that the same adjustable constant-force lifting device cannot meet the lifting adjustment requirements of different specifications of monitors.

[0007] To solve the above technical problem, a production process for a constant-force coil spring provided by the present invention mainly includes the following processes:

[0008] S1. Blank preparation;

[0009] S2. Cold rolling forming of the spring to obtain a preliminary finished spring;

[0010] S3. Heat treatment;

[0011] The cold rolling forming of the spring includes the following steps:

[0012] Step S21. Along the unfolding direction of the constant-force coil spring, the blank is divided into n segments, where n is a natural number and n≥2;

[0013] Step S22. When rolling the blank, the curvatures of the dies for rolling n segments are different, so that the spring stresses provided on the n segments are different.

[0014] By dividing the constant-force coil spring into several segments in the present invention, the curvatures during cold rolling of each segment are different, that is, different segments of the constant-force spring are rolled with pressure films of different arc radii (curvature radii). After rolling, the spring force provided by the constant-force spring within the same segment remains unchanged, while in the unfolding direction, the spring forces provided by the constant-force springs on different segments are different, thereby meeting the requirements of different support forces; when used as a screen support force source, the same constant-force spring can be used for the support devices of multiple specifications of monitors with different weights. Thus, the versatility of the support device is improved and the production cost is reduced.

[0015] Further, in the step S21, 3≤n≤10.

[0016] Further, in the step S21, the blank is evenly divided into n segments.

[0017] Further, in the step S22, the curvatures of the n segments of the blank decrease or increase sequentially along the unfolding direction of the constant-force coil spring.

[0018] Further, in the step S22, along the unfolding direction of the constant-force coil spring, the curvatures of the n segments of the blank decrease or increase linearly or in an arithmetic progression.

[0019] Further, the blank is a strip of 301 stainless steel, cold-rolled 3J21 iron-nickel alloy or spring steel sheet.

[0020] Further, in S2, the cold rolling forming method of the spring is a three-core roller rolling method.

[0021] Further, in S2, a spring forming machine is used to cold-roll and form the blank;

[0022] The spring forming machine includes a frame, a concave die, and a convex die;

[0023] The concave die and the convex die are oppositely arranged for spring rolling and forming;

[0024] The concave die is a V-shaped block and is slidably arranged on the frame; during the sliding process, it approaches or moves away from the convex die;

[0025] The convex die is a cam structure and is rotatably arranged on the frame;

[0026] The convex die is provided with n arc segments protruding radially, and the n arc segments are sequentially arranged along the circumferential direction of the convex die. The curvatures of the n arc segments correspond one-to-one to the curvatures of the n sections of the blank.

[0027] Further, the n arc segments are arranged in sequence along the axial direction.

[0028] Let the radius of curvature of the i-th arc segment be R i , and the curvature of the i-th section of the blank be K i = 1 / R i .

[0029] Wherein, 1 ≤ i ≤ n.

[0030] Further, the spring forming machine further includes a driving mechanism for driving the convex die to rotate.

[0031] Further, the heat treatment in step S3 specifically includes:

[0032] S31. Quenching treatment: quenching the preliminary finished spring;

[0033] S32. Tempering treatment: tempering the quenched preliminary finished spring.

[0034] By quenching, the hardness of the spring is increased, and the spring obtains higher strength; in addition, through high-temperature tempering treatment, the tensile stress generated during spring coiling is better eliminated.

[0035] Further, when performing the quenching treatment in step S31, the quenching temperature is controlled between 800 and 1100 °C.

[0036] Further, when performing the tempering treatment in step S32, the tempering temperature is controlled between 390 and 460 °C. Through tempering, the required mechanical properties can be obtained, the structure and dimensions of the spring can be stabilized, and the internal stress can be eliminated.

[0037] Preferably, during the quenching treatment, the semi-finished spring is placed in an induction heating furnace for heating. During the tempering treatment, the semi-finished spring is placed in a mesh belt tempering furnace for heating.

[0038] Furthermore, the production process of the constant force coil spring further includes the following processes:

[0039] Step S4. Spring grinding: Grind the two end faces of the semi-finished spring after tempering.

[0040] Step S5. Shot peening: Perform 1-3 times of shot peening on the semi-finished spring after the spring grinding step.

[0041] Multiple shot peenings are carried out by shot peening with shot grains of different sizes. For the first shot peening treatment, larger shot grains are used to obtain the peak value and depth of the residual compressive stress, and for the second shot peening treatment, smaller shot grains are used to improve the residual stress and surface quality of the spring surface and subsurface.

[0042] By setting segments that can provide different supporting forces, the constant force spring can be adjusted according to the weight of the display, so that the lifting seat can be lifted and lowered within a certain segment range. Within the same segment, the supporting force provided by the constant force spring is constant. Thus, the technical problem in the prior art that the same adjustable constant force lifting device cannot meet the lifting and adjustment requirements of different specifications of displays is solved.

[0043] The present invention also discloses a multi-segment constant force coil spring. Along the unfolding direction of the constant force coil spring, the constant force coil spring includes several segments, and the curvatures of each segment are different, and the spring forces provided by each segment are also different.

[0044] Furthermore, the constant force coil spring is evenly divided into 3-10 segments.

[0045] Furthermore, the curvatures of several segments of the constant force coil spring decrease or increase sequentially along the unfolding direction of the constant force coil spring.

[0046] Preferably, along the unfolding direction of the constant force coil spring, the curvatures of several segments of the constant force coil spring decrease or increase linearly or in an arithmetic progression.

[0047] Adopting the above technical solutions, the present invention has the following beneficial effects:

[0048] The production process of the constant force coil spring provided by the present invention is simple. The constant force spring includes several segments that can provide different supporting forces. By adjusting the starting position of the constant force spring, the lifting seat can be rolled up or retracted within a specific inner segment during the lifting process, that is, a specific segment provides the supporting force, and the supporting forces provided by different segments are different, so that it can be applicable to different specifications of displays. Description of the Drawings

[0049] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0050] Figure 1 It is a flowchart of the production process of the constant-force coil spring provided by the embodiment of the present invention;

[0051] Figure 2 It is a flowchart of the cold rolling forming process of the spring provided by the embodiment of the present invention;

[0052] Figure 3 It is a schematic diagram of the unfolded structure of the constant-force spring provided by the embodiment of the present invention;

[0053] Figure 4 It is a schematic diagram of the die structure for manufacturing a 4-section constant-force spring;

[0054] Figure 5 It is a side view of the punch.

[0055] Reference numerals:

[0056] 10 - female die; 20 - punch; 21 - arc section. Specific embodiments

[0057] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0058] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0059] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0060] The following further explains and illustrates the present invention in combination with specific embodiments.

[0061] As Figure 1 shown, a production process of a constant-force coil spring provided in this embodiment mainly includes the following processes:

[0062] S1. Blank preparation;

[0063] The blank is a strip of 301 stainless steel, cold-rolled 3J21 iron-nickel alloy, or spring steel sheet.

[0064] S2. Cold rolling forming of the spring to obtain a preliminary finished spring;

[0065] S3. Heat treatment;

[0066] As Figure 2 and 3 shown, in process S2, the cold rolling forming of the spring further includes the following steps:

[0067] Step S21. Along the unfolding direction of the constant-force coil spring, the blank is divided into n segments, where n is a natural number and n≥2;

[0068] Step S22. When rolling the blank, the curvatures of the dies for rolling the n segments are different, so that the spring stresses provided on the n segments are different.

[0069] In the present invention, by dividing the constant-force coil spring into several segments with different curvatures during cold rolling for each segment, that is, different segments of the constant-force spring are rolled with pressure films of different arc radii (curvature radii). After rolling, the spring force provided by the constant-force spring within the same segment remains unchanged, while in the unfolding direction, the spring forces provided by the constant-force springs on different segments are different. Thus, the requirements for different supporting forces can be met; when used as a screen supporting force source, the same constant-force spring can be used for the supporting devices of multiple specifications of displays with different weights. Thereby, the versatility of the supporting device is improved and the production cost is reduced.

[0070] In step S21, the blank is preferably evenly divided into 4 - 10 segments.

[0071] In step S22, the curvatures of the 4 - 10 segments of the blank decrease or increase sequentially along the unfolding direction of the constant-force coil spring.

[0072] More preferably, the curvatures of the n sections of the blank decrease or increase linearly or in an arithmetic progression, thereby facilitating quick adjustment of the support force during use.

[0073] In S2, the spring cold rolling forming method can be a three-core roller rolling method, and of course a dedicated forming machine can also be used.

[0074] When the blank is cold-rolled and formed by a spring forming machine, the spring forming machine includes a frame, a concave die and a convex die;

[0075] The concave die and the convex die are arranged opposite to each other for rolling forming of the spring.

[0076] Figure 4 A schematic diagram of the mold structure for manufacturing a 4-section constant force spring; Figure 5 It is a side view of the punch.

[0077] Take the forming of 4-section fixed force spring as an example. Figure 4 and 5 As shown, the female die 10 is a V-shaped block slidably disposed on a frame; during the sliding process, it approaches or moves away from the male die 20;

[0078] The punch 20 is a cam structure and is rotatably arranged on the frame; the punch 20 rotates under the drive of the driving mechanism.

[0079] The punch 20 is provided with four radially protruding arc segments 21 , which are arranged in sequence along the circumference of the punch 20 , and the curvatures of the four arc segments 21 are arranged in one-to-one correspondence with the curvatures of the four sections of the blank.

[0080] The four arc segments 21 are arranged in sequence along the axial direction.

[0081] When the i-th section of the tension coil spring is rolled, the punch 20 will rotate to the i-th arc section 21 .

[0082] Set the curvature radius of the i-th arc segment 21 to R i , the curvature of the i-th section of the blank is K i =1 / R i .

[0083] The heat treatment in step S3 specifically includes:

[0084] S31. Quenching treatment: quenching the initial finished spring;

[0085] S32. Tempering treatment: Temper the initially finished spring after quenching.

[0086] Through quenching, the hardness of the spring is increased, making the spring obtain higher strength; in addition, through high temperature tempering treatment, the tensile stress generated when the spring is rolled is better eliminated.

[0087] During the quenching treatment in step S31, the quenching temperature is controlled between 800 and 1100 °C.

[0088] During the tempering treatment in step S32, the tempering temperature is controlled between 390 and 460 °C. Through tempering, the required mechanical properties can be obtained, the structure and dimensions of the spring can be stabilized, and the internal stress can be eliminated.

[0089] Preferably, during the quenching treatment, the initial product spring is placed in an induction heating furnace for heating. During the tempering treatment, the initial product spring is placed in a mesh belt type tempering furnace for heating.

[0090] Finally, the production process of the constant force coil spring further includes the following processes:

[0091] Step S4. Grinding the spring: Grind the two end faces of the initial product spring after tempering.

[0092] Step S5. Shot peening: Perform 1 - 3 times of shot peening on the initial product spring after the grinding step.

[0093] Multiple shot peenings are carried out by shot peening with shot grains of different sizes. Larger shot grains are used for the first shot peening treatment to obtain the peak value and depth of the residual compressive stress, and smaller shot grains are used for the second shot peening treatment to improve the residual stress and surface quality of the spring surface and subsurface.

[0094] By setting segments that can provide different supporting forces, the constant force spring can be adjusted according to the weight of the display, so that the lifting seat can be lifted and lowered within a certain segment range, and within the same segment, the supporting force provided by the constant force spring is constant. Thus, the technical problem in the prior art that the same adjustable constant force lifting device cannot meet the lifting and adjusting requirements of different specifications of displays is solved.

[0095] A production process of a constant force coil spring provided by the present invention has a simple method. The constant force spring includes several segments that can provide different supporting forces. By adjusting the starting position of the constant force spring, the lifting seat can be rolled up or retracted within a specific inner segment during the lifting process, that is, a specific segment provides the supporting force, and the supporting forces provided by different segments are different, so that it can be applicable to different specifications of displays.

[0096] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A production process for a constant force coil spring, characterized in that: It mainly includes the following processes: S1. Blank preparation; S2. Cold rolling forming of the spring to obtain a preliminary finished spring; S3. Heat treatment; The cold rolling forming of the spring includes the following steps: Step S21. Along the unfolding direction of the constant force coil spring, the blank is divided into n segments, where n is a natural number and n≥2; Step S22. When the blank is rolled, the curvatures of the dies for rolling n segments are different, so that the spring stresses provided on the n segments are different; In S2, a spring forming machine is used to cold roll and form the blank; The spring forming machine includes a frame, a female die and a male die; The female die and the male die are arranged oppositely for spring rolling forming; The female die is a V-shaped block and is slidably arranged on the frame; during the sliding process, it approaches or moves away from the male die; The male die is a cam structure and is rotatably arranged on the frame; There are n radially protruding arc segments arranged on the male die, and the n arc segments are arranged in sequence along the circumferential direction of the male die, and the curvatures of the n arc segments are arranged in one-to-one correspondence with the curvatures of the n blanks; In step S3, the heat treatment specifically includes: S31. Quenching treatment: Quench the preliminary finished spring; The quenching temperature is controlled between 800 and 1100 °C; S32. Tempering treatment: Temper the preliminary finished spring after quenching; the tempering temperature is controlled between 390 and 460 °C.

2. The production process of the constant force coil spring according to claim 1, characterized in that: In step S22, the curvatures of the n blanks decrease or increase in sequence along the unfolding direction of the constant force coil spring.

3. The production process of the constant force coil spring according to claim 2, characterized in that: In step S22, along the unfolding direction of the constant force coil spring, the curvatures of the n blanks decrease or increase linearly or in an arithmetic progression in sequence.

4. The production process of the constant-force coil spring according to claim 1, characterized in that, The n arc segments are arranged in sequence along the axial direction.

5. The production process of the constant-force coil spring according to claim 1, characterized in that, It also includes the following processes: Step S4. Spring grinding treatment: Grind the two end faces of the preliminary finished spring after tempering; Step S5. Shot peening treatment: Perform 1-3 times of shot peening treatment on the preliminary finished spring after the spring grinding step.

6. A multi-segment constant-force coil spring prepared by using the constant-force coil spring production process according to any one of claims 1-5, characterized in that, Along the unfolding direction of the constant force coil spring, the constant force coil spring includes several segments, and the curvatures of each segment are different, and the spring forces provided by each segment are also different.

7. The multi-segment constant-force coil spring according to claim 6, wherein The curvatures of the several segments of the constant force coil spring decrease or increase in sequence along the unfolding direction of the constant force coil spring.

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