Spiral spring stretching and holding tool and thermal attenuation performance testing method
By adopting split coil spring stretching and holding tooling, and using cylinder brackets and urging mechanisms to achieve efficient stretching and fixing of coil springs, the problems of cumbersome equipment, large space occupation and safety hazards in the prior art are solved, and efficient, safe and accurate thermal attenuation performance testing is achieved.
Patent Information
- Application Number
- CN202311257781.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-27
- Publication Date
- 2025-03-28
AI Technical Summary
When testing the thermal attenuation performance of coil springs, the equipment is cumbersome, the space occupies a large amount, and there are safety hazards, and the processing accuracy is low, resulting in low testing efficiency and accuracy.
The removable split coil spring stretching and holding tooling is adopted, and the coil spring is efficiently stretched and fixed through the cylinder bracket and the urge mechanism. The cylinder body is closed and protected to ensure safety, and the volume of the high-temperature box is reduced through the split design.
It effectively reduces the volume of the high-temperature box, improves the efficiency and accuracy of testing, ensures the safety of operations, and lowers the test threshold.
Smart Images
Figure CN119714745A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of spiral spring testing, and in particular to a spiral spring stretching and holding tool and a thermal attenuation performance testing method. Background Art
[0002] After a coil spring has been used for a period of time, the spring tension value will decay to a certain extent. The thermal decay performance of the spring represents the degree of attenuation of the spring tension value. For example, the rear cover of an automobile product will use a coil spring structure to raise the rear cover and maintain its height. If the spring attenuation performance does not meet the technical specifications, after long-term use, the spring elasticity will decrease, resulting in the rear cover being difficult to raise or falling back after raising, causing user complaints. Therefore, the thermal attenuation performance of the spring is a key parameter that needs to be monitored regularly.
[0003] In the experiment to test the thermal attenuation performance of the spring, the spring needs to be stretched to the specified length and then placed in a high-temperature environment box for baking. Spring manufacturers generally use welded brackets, compress the brackets by forklifts to stretch the springs, and use steel pipes to support the brackets to maintain a fixed length. However, using the power of mechanical equipment such as forklifts to stretch and deform the springs requires the coordination of forklifts during the experiment, which is cumbersome and inefficient, and requires a larger space. In addition, the steel pipe brackets lack protective devices, and the spring stretching process is completely exposed to the outside, posing a safety hazard. On the other hand, the simple welded brackets used by spring manufacturers have low processing precision and large matching clearances. The forklift is used to control the stroke, which results in large errors and low precision.
[0004] Invention patent content
[0005] In order to solve the above technical problems, the present invention provides a coil spring stretching and holding tooling, which adopts a detachable split structure, and the cylindrical bracket occupies a small volume, which can effectively reduce the volume of the high temperature box; the coil spring is stretched in the cylindrical bracket through a force mechanism, and a fixing pin is used to maintain the stretched length of the coil spring, which is safe, labor-saving and highly precise.
[0006] The present invention solves the technical problem by adopting the following technical solution:
[0007] A coil spring stretching and holding tool, comprising a base, a force-applying device and a cylindrical bracket; wherein the force-applying device comprises a fixed bracket and a force-applying mechanism, the force-applying mechanism is arranged on the fixed bracket, and the fixed bracket is arranged on the base; the cylindrical bracket is detachably connected to the base, comprising a cylindrical body, a first head bracket, a second head bracket and a fixing pin; the cylindrical body is used to accommodate a coil spring; the first head bracket and the second head bracket are respectively arranged at the two ends of the cylindrical body, and the end of the first head bracket is provided with a first fixing piece for connecting the first end of the coil spring; when the coil spring is stretched, the force-applying end of the force-applying mechanism is connected to the second end of the coil spring; a limiting hole is provided at one end of the cylindrical body close to the second head bracket, and the limiting hole passes through the cylindrical body. When it is necessary to maintain the stretched length of the coil spring, the fixing pin is inserted into the limiting hole, and the second end of the coil spring is hung on the fixing pin.
[0008] Furthermore, the force-applying mechanism is a winch, comprising a rotating shaft bracket, a rotating shaft, a handle and a wire rope, the rotating shaft bracket is arranged on a fixed bracket, the rotating shaft passes through the rotating shaft bracket, the handle is arranged at one end of the rotating shaft, the other end of the rotating shaft is provided with a toothed disk, the rotating shaft bracket is provided with a rotatable hook, and the hook is engaged with the toothed disk; the wire rope is wound around the rotating shaft, and an open hook is provided at a free end thereof; or, the force-applying mechanism is a driving motor, comprising a motor body, a bobbin and a wire rope, the bobbin is rotatably connected to the output end of the motor body, the wire rope is wound around the bobbin, and an open hook is provided at a free end thereof, and the length of the wire rope extension can be adjusted according to the elongation of the coil spring, and the operation is labor-saving and convenient.
[0009] Furthermore, a pulley is provided at the end of the second head support, and the steel wire rope passes around the pulley. When the coil spring is stretched, the open hook is connected to the second end of the coil spring to change the direction of the pulling force, which is safer.
[0010] Furthermore, the fixed bracket is in the shape of an "X", having a top plate, two vertical plates and two flanges; a baffle is provided on the outer wall of the cylinder, the size of the baffle is larger than the width of the fixed bracket and / or the size of the baffle is larger than the height of the fixed bracket; preferably, the cylinder body is a cylinder, and the width and height of the fixed bracket are 1-1.2 times the diameter of the cylinder body, so that the cylindrical bracket is fixed with the fixed bracket, and disassembly and assembly are easier.
[0011] Furthermore, two fixing plates are provided on the base, and a slot with an opening at one end is provided at the bottom of each fixing plate, and the slots of the two fixing plates are arranged opposite to each other, and the two flanges of the fixing bracket can be inserted into the two slots from the two openings respectively; the base also includes a locking pin, and a first pin hole is provided at one end of the opening of the fixing plate, and the base is provided with a second pin hole aligned with the first pin hole, and the locking pin can be inserted into the first pin hole and the second pin hole, which is quick to disassemble and easy to operate.
[0012] Furthermore, a first notch and a second notch are respectively provided at both ends of the cylinder, and the first fixing member and the fixing pin are respectively exposed from the first notch and the second notch, so as to facilitate the measurement of the tensile length of the coil spring.
[0013] Furthermore, the first fixing member is a universal rotating ring, which is threadedly connected to the first head bracket through a threaded column, can match spiral spring hooks of different angles, and fine-tune the stretching length of the bolt spring.
[0014] Furthermore, there are multiple limiting holes, which are universal and suitable for the requirements of coil springs of different vehicle models.
[0015] Furthermore, a method for testing the thermal decay performance of a coil spring includes a coil spring stretching and holding method, wherein the coil spring stretching and holding method uses the coil spring stretching and holding tooling described above to stretch the coil spring and maintain the stretched length, and the stretching and holding method includes the following steps:
[0016] Step 1, placing the coil spring in the cylinder, so that the first end of the coil spring is hung on the first fixing member, and the second end is hung on the force applying end of the force applying mechanism;
[0017] Step 2: Install the fixed bracket and the cylindrical bracket on the base;
[0018] Step 3: The force applying end of the force applying mechanism stretches the coil spring until the second end of the coil spring reaches the limiting hole, and inserts the fixing pin into the limiting hole;
[0019] Step 4: Hang the second end of the coil spring on the fixing pin, and separate the force-applying end of the force-applying mechanism from the second end of the coil spring;
[0020] Step 5: Remove the fixed bracket and the cylindrical bracket.
[0021] Furthermore, the test method also includes testing the tension value of the coil spring, and the specific method is:
[0022] Before step 1, the tension value of the original coil spring is tested, and the tension value F1 of the original coil spring is recorded;
[0023] After step 5, the cylindrical bracket with the coil spring installed is placed in a high temperature box at a temperature of T and baked for t hours, then the coil spring is removed from the cylindrical bracket, the tension value of the coil spring is tested, and the tension value F2 of the coil spring after thermal attenuation is recorded.
[0024] Further, the method of removing the coil spring from the cartridge bracket comprises the following steps:
[0025] Step 61, installing the cylindrical bracket with the coil spring on the base;
[0026] Step 62, hang the force-applying end of the force-applying mechanism on the second end of the coil spring, stretch the coil spring, and move the fixing pin out of the limiting hole;
[0027] Step 63, the force applying mechanism operates in the reverse direction to restore the coil spring to its original length;
[0028] Step 64, remove the first end of the coil spring from the first fixing member, remove the second end of the coil spring from the force-applying end of the force-applying mechanism; and remove the coil spring from the cylinder.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] (1) The tool adopts a split structure. When stretching the coil spring, the cylindrical bracket is installed on the base, the coil spring is stretched to the specified length through the force-applying mechanism, and the coil spring is fixed with a fixing pin. Then the cylindrical bracket is removed from the base, the tool is disassembled, and the cylindrical bracket and the coil spring inside are placed in a high-temperature oven for baking. In this way, the volume of the high-temperature oven can be effectively reduced. The cylindrical bracket with a compact design occupies a small volume and is light in weight. A small-volume high-temperature oven can be used, thereby lowering the test threshold for the thermal attenuation performance test of the coil spring.
[0031] (2) The stretching and contraction of the tested coil spring are both carried out in the cylinder. The cylinder wall and the head brackets at both ends are closed and protected, which can effectively prevent the coil spring from suddenly breaking and flying out, avoiding injuries to operators and ensuring safety.
[0032] (3) The tooling has the function of fine-tuning the elongation of the coil spring, which reduces the impact of processing accuracy and the material strength of the tooling itself on the test results and improves measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 It is a schematic diagram of the structure of the helical spring stretching and retaining tooling of the present invention.
[0034] Figure 2 This is a perspective view of the structure schematic diagram of the helical spring stretching and holding tool of the present invention when the helical spring length is maintained.
[0035] Figure 3 It is a schematic structural diagram of the force-applying device of the helical spring stretching and retaining tooling of the present invention.
[0036] Figure 4 It is a schematic diagram of the fixing plate structure of the helical spring stretching and holding tooling of the present invention.
[0037] In the figure: 1-base; 11-fixed plate; 12-slot; 13-locking pin; 2-cylindrical bracket; 21-cylinder; 22-first head bracket; 221-universal rotating ring; 222-threaded column; 23-second head bracket; 24-fixed pin; 25-pulley; 26-baffle; 3-fixed bracket; 31-top plate; 32-vertical plate; 33-flange; 4-capstan; 41-rotating shaft bracket; 42-rotating shaft; 43-handle; 44-wire rope; 441-open hook; 45-toothed disc; 46-hook; 5-helical spring. DETAILED DESCRIPTION
[0038] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.
[0039] In the description of the present invention, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. In addition, it should be noted that the terms "inside" and "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the product of the invention is usually placed when in use, or the directions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the equipment or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.
[0040] The present invention provides a helical spring 5 stretching and holding tool, such as Figure 1As shown, it includes a base 1, a force-applying device and a cylindrical bracket 2. The force-applying device includes a fixed bracket 3 and a force-applying mechanism, and the force-applying mechanism is arranged on the fixed bracket 3, and the fixed bracket 3 is arranged on the base 1. The cylindrical bracket 2 is detachably connected to the base 1, and includes a cylinder 21, a first head bracket 22, a second head bracket 23 and a fixing pin 24; the cylinder 21 is used to accommodate a coil spring 5; the first head bracket 22 and the second head bracket 23 are respectively arranged at the two ends of the cylinder 21, and the end of the first head bracket 22 is provided with a first fixing member for connecting the first end of the coil spring 5. When the coil spring 5 is stretched, the force-applying end of the force-applying mechanism is connected to the second end of the coil spring 5; a limiting hole is arranged at one end of the cylinder 21 close to the second head bracket 23, and the limiting hole passes through the cylinder 21. When it is necessary to maintain the stretched length of the coil spring 5, the fixing pin 24 is inserted into the limiting hole, and the second end of the coil spring 5 is hung on the fixing pin 24.
[0041] When the tool is used to stretch the coil spring 5, the second end of the coil spring 5 can be hung on the force-applying end of the force-applying mechanism, the coil spring 5 can be installed into the cylinder 21 from the second head bracket 23 side, and the first end of the coil spring 5 can be hung on the first fixing member, so that the coil spring 5 can be installed into the cylinder 21. Then the cylinder bracket 2 is connected to the base 1, and then the force-applying mechanism applies force to stretch the coil spring 5 until the coil spring 5 is stretched to the limiting hole, the fixing pin 24 is inserted into the limiting hole, and the second end of the coil spring 5 is hung on the fixing pin 24. Then, the two ends of the coil spring 5 are hung on the first fixing member and the fixing pin 24 respectively, and the stretched length of the coil spring 5 remains unchanged. Figure 2 The tool adopts a split structure. When the coil spring 5 is stretched, the cylindrical bracket 2 is installed on the base 1, the coil spring 5 is stretched to a specified length by the force-applying mechanism, and the coil spring 5 is fixed with a fixing pin 24, as shown in FIG. Figure 1 Then remove the cylindrical support 2 from the base 1, disassemble the tooling, and put the cylindrical support 2 and the coil spring 5 therein into a high temperature oven for baking. Figure 2 As shown, the volume of the high temperature box can be effectively reduced. The compact cylindrical bracket 2 occupies a small volume and is light in weight, and a small volume high temperature box can be used, thereby reducing the test threshold for the thermal decay performance test of the coil spring 5.
[0042] The cylinder 21 is the main body of the cylinder bracket 2. The stretching and contraction of the tested coil spring 5 are both performed in the cylinder 21. The cylinder wall can effectively prevent the coil spring 5 from suddenly breaking and causing rebound, which causes the coil spring 5 to fly out laterally, avoiding injuries to operators and ensuring safety. The first head bracket 22 and the second head bracket 23 are respectively installed at both ends of the cylinder 21 to form a closed end. The first head bracket 22 and the second head bracket 23 can be set to a U shape, and their length is set to 1 / 2-3 / 4 of the original length of the coil spring 5, and the height is at least 1 / 2 of the cylinder 21, which is convenient for the coil spring 5 to be loaded or taken out of the cylinder 21, and can prevent the coil spring 5 from flying out from the end.
[0043] It takes about 300N-400N of pulling force to pull the coil spring 5 to the design stretching length specified in the drawing, and the force can only be applied to the hooks at both ends of the coil spring 5. The force-bearing area is small and it is difficult to pull it manually. In order to facilitate pulling the coil spring 5, the force-applying mechanism can be set as a winch 4, refer to Figure 3 As shown, it includes a rotating shaft bracket 41, a rotating shaft 42, a handle 43 and a wire rope 44. The rotating shaft bracket 41 is arranged on the fixed bracket 3, the rotating shaft 42 passes through the rotating shaft bracket 41, and the handle 43 is arranged at one end of the rotating shaft 42; the wire rope 44 is wound around the rotating shaft 42, and an open hook 441 is arranged at its free end. When the coil spring 5 is stretched, the open hook 441 of the wire rope 44 is hooked on the hook of the coil spring 5, and the handle 43 is rotated to tighten the wire rope 44, so that the coil spring 5 can be gradually stretched; when the coil spring 5 is shortened, the handle 43 can be rotated in the opposite direction to gradually lengthen the wire rope 44, so that the coil spring 5 is retracted. The coil spring 5 is tightened by the wire rope 44, and the length of the wire rope 44 extending out of the rotating shaft 42 can be adjusted according to the elongation of the coil spring 5, so that the force applying mechanism can be set in a safe position and the position of the force applying mechanism can be kept unchanged. The force applying mechanism has a simple structure and is easy to operate. Preferably, the handle 43 is plugged into the rotating shaft 42 so that the length of the handle 43 is adjustable. When the stretched coil spring 5 is in the initial stage, the elastic force of the coil spring 5 is small, and the handle 43 can be shortened to improve the stretching efficiency. When the stretched coil spring 5 is in the final stage, the elastic force of the coil spring 5 is large, and the handle 43 can be lengthened to increase the force arm, so that a larger torque can be obtained under the same force, thereby achieving the purpose of saving effort. In order to improve safety, a toothed disc 45 is provided at the other end of the rotating shaft 42, and a rotatable hook 46 is provided at the rotating shaft bracket 41, and the hook 46 is engaged with the toothed disc 45. When the handle 43 is rotated to stretch the coil spring 5, the toothed disc 45 and the hook 46 are engaged and rotated, so that the coil spring 5 can be gradually stretched, and the reverse rotation of the rotating shaft 42 can be prevented, and the steel wire rope 44 can be lengthened, so that the coil spring 5 suddenly retracts and flies out to cause injury, thereby further improving safety. When the hook 46 is lifted, the handle 43 can be rotated in the reverse direction to shrink the steel wire rope 44, or the steel wire rope 44 can be pulled quickly.
[0044] In order to save more effort during stretching, the force-applying mechanism can also be set as a driving motor, including a motor body, a spool and a wire rope 44. The spool is rotatably connected to the output end of the motor body, and the wire rope 44 is wound around the spool, and an open hook 441 is provided at its free end.
[0045] Preferably, a pulley 25 is provided at the end of the second head bracket 23, and the steel wire rope 44 passes through the pulley 25. When the coil spring 5 is stretched, the open hook 441 is connected to the second end of the coil spring 5. The retraction force of the coil spring 5 and the pulling force of the steel wire rope 44 can be converted into torque through the pulley 25, and the purpose of saving effort can be achieved by changing the length of the force arm. The direction of the pulling force of the force-applying mechanism can also be changed through the pulley 25. The force-applying mechanism is installed in the middle position of the cylindrical bracket 2, which can save space and facilitate operation. It can also make the operator and the stretching direction of the coil spring 5 not in the same direction. When the coil spring 5 suddenly breaks and flies out, the operator is not easily hit, which is safer.
[0046] In some embodiments, reference Figure 1 and Figure 3 As shown, the fixed bracket 3 is in the shape of a Chinese character "J", and has a top plate 31, two vertical plates 32 and two flanges 33; the outer wall of the cylinder 21 is provided with a baffle 26, and the size of the baffle 26 is greater than the width of the fixed bracket 3 and / or the size of the baffle 26 is greater than the height of the fixed bracket 3. An accommodation space is formed between the vertical plate 32 and the top plate 31 of the Chinese character "J". When the cylindrical bracket 2 is installed, the cylindrical bracket 2 is placed between the two vertical plates 32 of the fixed bracket 3. When the force-applying mechanism applies force, the coil spring 5 generates a retraction force. Under the action of the retraction force of the coil spring 5 and the pulling force of the force-applying mechanism, the cylindrical bracket 2 moves toward the fixed bracket 3 as a whole. The setting position of the baffle 26 needs to make the baffle 26 move with the cylinder 21 toward the fixed bracket 3 until the baffle 26 abuts against the fixed bracket 3, and the cylindrical bracket 2 is blocked by the fixed bracket 3. When the force-applying mechanism stretches the coil spring 5, the cylindrical bracket 2 remains in position unchanged, thereby achieving the fixation of the cylindrical bracket 2. When the pulling force of the force-applying mechanism changes direction through the pulley 25, the baffle 26 is arranged between the fixed bracket 3 and the second head bracket 23. Preferably, the baffle 26 is fixed near the second head bracket 23 and is located at 2 / 5-3 / 5 of the length of the entire cylindrical bracket 2. When disassembling, the cylindrical bracket 2 can be directly taken out. The cylindrical bracket 2 is fixed in coordination with the fixed bracket 3, which makes disassembly and assembly easier and the operation more convenient.
[0047] In some embodiments, the barrel 21 is a cylinder, and the width (the distance between the two vertical plates 32) and the height (the distance from the top plate 31 to the base 1) of the fixed bracket 3 are 1-1.2 times the diameter of the barrel 21. Preferably, the width and height of the fixed bracket 3 are the same, roughly the same as the diameter of the barrel 21 or slightly larger than the diameter of the barrel 21, so that the cylindrical bracket 2 can be easily placed between the two vertical plates 32, and the vertical plates 32 and the top plate 31 can clamp the cylindrical bracket 2. Correspondingly, the baffle 26 can be set to a circular shape, and the diameter of the baffle 26 is 1.2-1.5 times the diameter of the cylinder, which can effectively abut against the fixed bracket 3. Preferably, the contact position between the baffle 26 and the base 1 can be cut along the surface of the cylinder. For example, the baffle 26 can be set to a semicircle, so that the cylinder is in full contact with the base 1, and the base 1 stably supports the barrel 21.
[0048] According to the width of the "X"-shaped fixing bracket 3 and the size of the cylinder 21, the "X"-shaped fixing bracket 3 can be fixedly arranged on the base 1, and the cylinder 21 is directly inserted between the two vertical plates 32. In order to improve the convenience of operation and make the installation of the cylinder bracket 2 more convenient and quick, the "X"-shaped fixing bracket 3 can also be detachably connected to the base 1. Specifically, Figure 4 As shown, two fixing plates 11 are arranged on the base 1, and a slot 12 with an opening at one end is arranged at the bottom of each fixing plate 11, and the slots 12 of the two fixing plates 11 are arranged opposite to each other, and the two flanges 33 of the fixing bracket 3 can be inserted into the two slots 12 from the two openings respectively; the base 1 also includes a locking pin 13, and a first pin hole is arranged at one end of the opening of the fixing plate 11, and the base 1 is provided with a second pin hole aligned with the first pin hole, and the locking pin 13 can be inserted into the first pin hole and the second pin hole.
[0049] When installing the cylindrical bracket 2, the cylindrical bracket 2 can be placed between the two fixing plates 11, one end of the slot 12 of the fixing plate 11 is closed and the other end is open, the fixing bracket 3 is clamped on the cylindrical bracket 2, located on the side of the opening, and then the two flanges 33 of the fixing bracket 3 are respectively inserted into the slot 12 from the openings of the two fixing plates 11, and then the two locking pins 13 are respectively inserted into the first pin hole and the second pin hole, and one end of the fixing bracket 3 is blocked by the end of the fixing plate 11 and the other end is blocked by the locking pin 13, so that the fixing bracket 3 is fixed on the base 1, and the cylindrical bracket 2 is connected to the base 1. There are at least two locking pins 13, and the number of the first pin hole and the second pin hole corresponds to the number of the locking pins 13. When disassembling, pull out the locking pin 13 and move the two flanges 33 out of the opening. The fixing bracket 3 is fixed on the base 1 by the combination of the slot 12 and the locking pin 13, which is quick to disassemble and assemble, and the operation is very convenient. It can also prevent the fixing bracket 3 from slipping out of the slot 12 due to misoperation, resulting in failure of the stretching operation.
[0050] In order to facilitate the measurement of the stretching length of the coil spring 5, the two ends of the cylinder 21 are respectively provided with a first notch and a second notch, and the first fixing member and the fixing pin 24 are respectively exposed in the first notch and the second notch. When the coil spring 5 is subjected to thermal attenuation baking, it needs to be stretched to the design stretching length specified in the coil spring 5 drawing and maintained at the design stretching length. For example, the design stretching length of the coil spring 5 of a certain vehicle model is 500.2mm, and the design stretching length of the coil spring 5 of another vehicle model is 532.2mm. The design stretching length has high precision and can be measured using a large-range vernier caliper. Through the first notch and the second notch, the vernier caliper can be conveniently operated to measure the stretching length of the coil spring 5, that is, to measure the distance between the first fixing member and the fixing pin 24. The operation is convenient, the measurement is accurate, and the measurement accuracy is high.
[0051] In some embodiments, the first fixing member is a universal rotating ring 221, which can rotate freely 360 degrees and can match the coil spring 5 hooks of different angles.
[0052] In some embodiments, the universal rotating ring 221 is threadedly connected to the first head bracket 22 via a threaded column 222. According to the design elongation requirement of the coil spring 5, the opening position of the limit hole on the cylindrical bracket 2 can be determined, that is, the position of the fixing pin 24 can be determined. When the coil spring 5 is stretched to the fixed position and the hook at one end is hung on the fixing pin 24, the actual elongation of the coil spring 5 (the elongation of the coil spring 5 = the distance between the universal rotating ring 221 and the fixing pin 24 - the original length of the coil spring 5) may be different from the required design elongation due to reasons such as processing accuracy and material deformation. A universal rotating ring 221 of the base of the threaded column 222 is installed in the middle position of the first head bracket 22, a threaded hole is processed in the first bracket, and the threaded column 222 is threadedly connected with the first head bracket 22. After the hook at one end of the coil spring 5 is hung on the fixing pin 24, the other end can adjust the elongation of the coil spring 5 by rotating the height of the threaded column 222, thereby fine-tuning the stretched length of the coil spring 5, compensating for the elongation difference, and reducing the influence of the processing accuracy and the material strength of the tooling itself on the test results. Of course, in order to make the threaded column 222 more reliably connected and prevent it from being pulled and moved by the coil spring 5, a nut can be set on the threaded column 222.
[0053] In some embodiments, the limiting holes are multiple, and can be set to two, three, etc. according to the design elongation requirements specified in the drawings of the coil springs 5 of different models, so that the tooling has universality and is applicable to the requirements of the coil springs 5 of different models. For example, the design elongation length of the coil spring 5 of a certain model is 500.2mm, and the design elongation length of the coil spring 5 of another model is 532.2mm. Two limiting holes can be set on the cylinder 21, so that the distances between the two limiting holes and the universal rotating ring 221 are 500.2mm and 532.2mm respectively. The distances between the two limiting holes and the universal rotating ring 221 can also be set to 500mm and 532mm respectively, and the elongation can be compensated by the threaded column 222.
[0054] The present invention also provides a method for testing the thermal decay performance of a coil spring 5, including a method for stretching and holding a coil spring 5, wherein the method for stretching and holding a coil spring 5 uses the above-mentioned coil spring 5 stretching and holding tool to stretch the coil spring 5 and maintain the stretched length, and the method for stretching and holding a coil spring 5 includes the following steps:
[0055] Step 1, placing the coil spring 5 in the cylinder 21, so that the first end of the coil spring 5 is hung on the first fixing member, and the second end is hung on the force applying end of the force applying mechanism;
[0056] Step 2, installing the fixed bracket 3 and the cylindrical bracket 2 on the base 1;
[0057] Step 3: The force applying end of the force applying mechanism stretches the coil spring 5 until the second end of the coil spring 5 reaches the limiting hole, and the fixing pin 24 is inserted into the limiting hole;
[0058] Step 4: Hang the second end of the coil spring 5 on the fixing pin 24, and separate the force-applying end of the force-applying mechanism from the second end of the coil spring 5;
[0059] Step 5: Remove the fixed bracket 3 and the cylindrical bracket 2.
[0060] Using the coil spring 5 stretching and holding tool, executing steps 1 to 5 can stretch the coil spring 5 to the designed stretching length specified in the coil spring 5 drawing.
[0061] The test method further includes testing the tension value of the coil spring 5, and the specific method is:
[0062] Before step 1, the tension value of the original coil spring 5 is tested, and the tension value F1 of the original coil spring 5 is recorded;
[0063] After step 5, the cylindrical bracket 2 equipped with the coil spring 5 is placed in a high temperature box at a temperature of T and baked for t hours, then the coil spring 5 is removed from the cylindrical bracket 2, the tension value of the coil spring 5 is tested, and the tension value F2 of the coil spring 5 after thermal attenuation is recorded.
[0064] To test the thermal decay performance of the coil spring 5, it is necessary to test the tension values of the original coil spring 5 and the coil spring 5 after thermal decay according to GB / T 1239.1-2009 Technical Conditions for Cold-rolled Cylindrical Coil Spring 5 Part 1: Tension Spring. Before step 1, test the tension value of the original coil spring 5, record the tension value F1 of the original coil spring 5, and then use the tool to stretch the coil spring 5. Then remove the cylindrical bracket 2 from the base 1, disassemble the tool, and put the cylindrical bracket 2 and the coil spring 5 inside into a high temperature box at 80℃-100℃ for baking for 16-72 hours. The baking time and baking temperature can be set according to the drawing requirements of the coil spring 5. For example, put it in a high temperature box at 80℃ and bake it for 16 hours to decay the performance of the coil spring 5. Then, the coil spring 5 is disassembled from the cylinder bracket 2, and the tension value of the coil spring 5 after thermal attenuation is tested, and the tension value F2 of the coil spring 5 after thermal attenuation is recorded, and the thermal attenuation value ΔF of the tension of the coil spring 5 is F1-F2. For example, for a coil spring 5 of a certain vehicle model, the tension value is 328N before baking, and the tension value is 320N after baking, and the thermal attenuation value ΔF of the tension of the coil spring 5 is 8N.
[0065] When testing the tension value of the baked coil spring 5, it is necessary to remove the coil spring 5 from the cylindrical bracket 2. The coil spring 5 is fixed in the cylindrical bracket 2, and the tension is increased. If it is directly taken out, it is easy to fly out and cause danger. In order to improve safety, the tool can be used to slowly shorten the coil spring 5. Specifically, the method of removing the coil spring 5 from the cylindrical bracket 2 includes the following steps:
[0066] Step 61, installing the cylindrical bracket 2 with the coil spring 5 on the base 1;
[0067] Step 62, hang the force-applying end of the force-applying mechanism on the second end of the coil spring 5, stretch the coil spring 5, and move the fixing pin 24 out of the limiting hole. Under the retraction force of the coil spring 5, the hook of the coil spring 5 is firmly hung on the fixing pin 24, and the fixing pin 24 is firmly fixed on the cylindrical bracket 2, making it difficult to remove. The force-applying mechanism can be used to slightly stretch the coil spring 5, so that the hook of the coil spring 5 is slightly lifted, so that the fixing pin 24 is separated from the hook of the coil spring 5, and then the fixing pin 24 is easily removed.
[0068] Step 63, the force applying mechanism operates in the reverse direction to restore the coil spring 5 to its original length;
[0069] Step 64 , remove the first end of the coil spring 5 from the first fixing member, remove the second end of the coil spring 5 from the force-applying end of the force-applying mechanism; and remove the coil spring 5 from the cylinder 21 .
[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A helical spring stretching and retaining tool, characterized in that: It includes a base, a force-applying device and a cylindrical bracket; wherein, The force applying device comprises a fixed bracket and a force applying mechanism, wherein the force applying mechanism is arranged on the fixed bracket, and the fixed bracket is arranged on a base; The cylindrical bracket is detachably connected to the base, and includes a cylindrical body, a first head bracket, a second head bracket and a fixing pin; the cylindrical body is used to accommodate a coil spring; the first head bracket and the second head bracket are respectively arranged at the two ends of the cylindrical body, and the end of the first head bracket is provided with a first fixing member for connecting the first end of the coil spring; when the coil spring is stretched, the force-applying end of the force-applying mechanism is connected to the second end of the coil spring; a limiting hole is provided at one end of the cylindrical body close to the second head bracket, and the limiting hole passes through the cylindrical body. When it is necessary to maintain the stretched length of the coil spring, the fixing pin is inserted into the limiting hole, and the second end of the coil spring is hung on the fixing pin.
2. The helical spring stretching and retaining tool according to claim 1, characterized in that: The force-applying mechanism is a winch, comprising a rotating shaft bracket, a rotating shaft, a handle and a steel wire rope, wherein the rotating shaft bracket is arranged on a fixed bracket, the rotating shaft passes through the rotating shaft bracket, the handle is arranged at one end of the rotating shaft, and a toothed disc is arranged at the other end of the rotating shaft, and the rotating shaft bracket is provided with a rotatable hook, and the hook is engaged with the toothed disc; the steel wire rope is wound around the rotating shaft, and an open hook is arranged at a free end thereof; or, the force-applying mechanism is a driving motor, comprising a motor body, a bobbin and a steel wire rope, the bobbin is rotatably connected to the output end of the motor body, the steel wire rope is wound around the bobbin, and an open hook is arranged at a free end thereof.
3. The helical spring stretching and retaining tool according to claim 2, characterized in that: A pulley is provided at the end of the second head support, and the steel wire rope passes around the pulley. When the coil spring is stretched, the open hook is connected to the second end of the coil spring.
4. The helical spring stretching and retaining tool according to claim 1, 2 or 3, characterized in that: The fixed bracket is in the shape of an "X", and has a top plate, two vertical plates and two flanges; a baffle is provided on the outer wall of the cylinder, and the size of the baffle is larger than the width of the fixed bracket and / or the size of the baffle is larger than the height of the fixed bracket; preferably, the cylinder is a cylinder, and the width and height of the fixed bracket are 1-1.2 times the diameter of the cylinder.
5. The helical spring stretching and retaining tool according to claim 4, characterized in that: Two fixing plates are arranged on the base, and a slot with an opening at one end is arranged at the bottom of each fixing plate, and the slots of the two fixing plates are arranged opposite to each other, and the two flanges of the fixing bracket can be inserted into the two slots from the two openings respectively; the base also includes a locking pin, and a first pin hole is arranged at one end of the opening of the fixing plate, and the base is provided with a second pin hole aligned with the first pin hole, and the locking pin can be inserted into the first pin hole and the second pin hole.
6. The helical spring stretching and retaining tool according to claim 1, characterized in that: The two ends of the cylinder are respectively provided with a first notch and a second notch, and the first fixing member and the fixing pin are respectively exposed from the first notch and the second notch.
7. The helical spring stretching and retaining tool according to claim 1, characterized in that: The first fixing member is a universal rotating ring, and the universal rotating ring is threadedly connected to the first head bracket through a threaded column.
8. The helical spring stretching and retaining tool according to claim 1 or 7, characterized in that: There are multiple limiting holes.
9. A method for testing the thermal decay performance of a coil spring, characterized in that: The invention comprises a method for stretching and holding a coil spring, wherein the method uses the coil spring stretching and holding tool according to any one of claims 1 to 8 to stretch the coil spring and maintain the stretched length, and the method comprises the following steps: Step 1, placing the coil spring in the cylinder, so that the first end of the coil spring is hung on the first fixing member, and the second end is hung on the force applying end of the force applying mechanism; Step 2: Install the fixed bracket and the cylindrical bracket on the base; Step 3: The force applying end of the force applying mechanism stretches the coil spring until the second end of the coil spring reaches the limiting hole, and inserts the fixing pin into the limiting hole; Step 4: Hang the second end of the coil spring on the fixing pin, and separate the force-applying end of the force-applying mechanism from the second end of the coil spring; Step 5: Remove the fixed bracket and the cylindrical bracket.
10. The method for testing the thermal decay performance of a coil spring according to claim 9, characterized in that: The test method also includes testing the tension value of the coil spring, and the specific method is: Before step 1, the tension value of the original coil spring is tested, and the tension value F1 of the original coil spring is recorded; After step 5, the cylindrical bracket with the coil spring installed is placed in a high temperature box at a temperature of T and baked for t hours, then the coil spring is removed from the cylindrical bracket, the tension value of the coil spring is tested, and the tension value F2 of the coil spring after thermal attenuation is recorded.
11. The method for testing the thermal decay performance of a coil spring according to claim 10, characterized in that: The method of removing the coil spring from the cartridge bracket comprises the following steps: Step 61, installing the cylindrical bracket with the coil spring on the base; Step 62, hang the force-applying end of the force-applying mechanism on the second end of the coil spring, stretch the coil spring, and move the fixing pin out of the limiting hole; Step 63, the force applying mechanism operates in the reverse direction to restore the coil spring to its original length; Step 64, remove the first end of the coil spring from the first fixing member, remove the second end of the coil spring from the force-applying end of the force-applying mechanism; and remove the coil spring from the cylinder.