阅读说明：本技术 端头采用预压处理的压缩弹簧及其绕制和检测方法 (Compression spring with prepressing end and winding and detecting method thereof ) 是由 陈华健 郝国华 朱文奇 李斌 胡健 蔡栋 侯世玉 章胡涛 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种端头采用预压处理的压缩弹簧及其绕制和检测方法,包括有弹簧本体,弹簧本体的两端头与其对应的邻圈之间间隙均为d,弹簧本体在受力压缩到指定位置时端头与邻圈接触区域的大小为压紧角度θ；压紧角度θ为通过感应纸测量时弹簧端头及其邻圈接触处所产生的压痕曲线与弧度中心位置处所形成的夹角；在绕制过程中及时调整弹簧本体在绕制过程中的节距,保证弹簧端头与邻圈有充分的接触且在弹簧两端磨削后同样存在；检测时首先判定端头间隙是否满足要求,如端头间隙满足要求,再对预压角度进行检测,只有两者全部满足要求,才能保证端头与邻圈并紧。本发明通过改变弹簧的结构,从而避免弹簧受力压缩后容易出现末圈断裂的情况。(The invention discloses a compression spring with prepressing end heads and a winding and detecting method thereof, comprising a spring body, wherein gaps between two end heads of the spring body and adjacent rings corresponding to the end heads are d, and the size of a contact area between the end head and the adjacent ring is a pressing angle theta when the spring body is stressed and compressed to a specified position; the pressing angle theta is an included angle formed by an indentation curve generated at the contact position of the spring end and the adjacent ring thereof and the central position of the radian when the sensing paper is used for measurement; the pitch of the spring body in the winding process is adjusted in time in the winding process, so that the end of the spring is ensured to be in full contact with an adjacent ring and also exists after the two ends of the spring are ground; when detecting, whether the end gap meets the requirement is judged firstly, if the end gap meets the requirement, the prepressing angle is detected, and only if the two meet the requirement, the end and the adjacent ring can be ensured to be tight. According to the invention, the situation that the tail ring is easy to break after the spring is stressed and compressed is avoided by changing the structure of the spring.)

1. The utility model provides a compression spring that end adopts pre-compaction, its characterized in that: the spring body is produced and processed by prepressing, a gap d is formed between two ends of the spring body and an adjacent ring corresponding to the spring body, and the size of a contact area between the ends and the adjacent ring is a pressing angle theta when the spring body is stressed and compressed; and the pressing angle theta is an included angle formed by an indentation curve generated at the contact position of the spring end and the adjacent ring and the central position of the radian when the sensing paper is used for measurement.

2. A compression spring capable of being pre-stressed as claimed in claim 1, wherein: the clearance d is less than or equal to 0.1 mm.

3. A compression spring capable of being pre-stressed as claimed in claim 1, wherein: when the pressing angle theta is stressed and compressed to different positions, the angle between the end of the pressing angle theta and the contact area of the adjacent ring is different, when the spring body is compressed to the installation position H1, the corresponding pressing angle theta 1 is larger than 36 degrees, and when the spring body is compressed to the maximum working position H2, the detected indentation curve on the sensing paper is continuous, and the formed angle theta 2 is larger than 120 degrees; the detected indentation curve on the sensing paper is discontinuous, and the formed two angles theta 3 is larger than 12 degrees and theta 4 is larger than 100 degrees.

4. A method for winding a compression spring with a prepressed end head based on the method in claim 1, which is characterized in that: the spring body with the structure needs to give initial pre-pressure in the end winding process, the pitch of the spring body in the winding process is adjusted in time, the axial movement of the corresponding winding wheel is adjusted at the same time, the contact area of the end and the adjacent ring is increased when the end is tightly pressed, and the spring end and the adjacent ring are ensured to be in full contact and exist after the two ends of the spring are ground;

the method comprises the following specific steps:

(1) setting target values of the pitch and the outer diameter winding of the spring, and adjusting the position of a corresponding winding roller on winding equipment according to the target values; meanwhile, the movement position of the corresponding pitch pin is adjusted according to the clearance d between the end head of the compression spring and the corresponding adjacent ring and the pitch required by the spring;

(2) the wire material is unreeled through the unreeling mechanism, and the end part of the wire material sequentially passes through the feeding roller and the guide plate and is fed into the reeling mechanism; in order to ensure that the pressing angle theta meets the requirement during winding, the pitch of the end head and the adjacent ring is controlled through a pitch pin, and the axial movement of the winding rollers is adjusted and controlled at the same time, so that a certain angle is formed between the upper winding roller and the lower winding roller in the axial direction, the angle is 12-45 degrees, and the pre-pressure generated by winding enables a larger contact area to be generated between the end head and the adjacent ring, so that the indentation effect of the adjacent ring and the end head is ensured, and the pressing angle theta is ensured;

(3) after the end coiling, require the position of equipment automatic adjustment pitch round pin according to the pitch of the spring body that corresponds, at this moment, for guaranteeing the pre-compaction effect of adjacent circle and end, there are two kinds of schemes:

the first is that the angle formed by the winding roller in the axial direction does not need to be restored in the process, so that the continuous winding is ensured until the prepressing is always existed in the process of the tail end of the spring, and after the tail end is wound, the cutting knife cuts off the material, so that the continuous winding of the spring body with the axial spiral offset and the prepressing of the whole spring can be obtained;

and secondly, after the winding of the end and the adjacent coil is finished, the axial angle of the winding roller is immediately recovered, the middle section of the spring body can be wound after the axial angle is recovered, after the winding of the middle section meets the corresponding requirement, the axial motion of the winding roller is adjusted and controlled again, so that the upper winding roller and the lower winding roller form a certain angle in the axial direction, the angle is 12-45 degrees, the winding with pre-pressure between the tail end and the adjacent coil is realized, after the winding of the tail end, the cutting knife cuts off the material, the pre-pressure between the end with two ends and the adjacent coil can be obtained, and the middle section of the spring body is normally wound.

5. The method for winding the compression spring with the pre-pressed end head according to claim 4 is characterized in that: the coiling equipment comprises a workbench, wherein a vertical plate is erected on the workbench, a feeding station and a coiling station are sequentially arranged on the vertical plate, the feeding end of the workbench is an unreeling station, a wire unreeling mechanism is installed on the unreeling station, upper and lower rows of rolling conveying wheels arranged in an array at intervals are distributed on the vertical plate corresponding to the feeding station, a guide rail for stabilizing the discharging direction and position of a wire is installed at the discharging end of each rolling conveying wheel through a mounting seat, a spring coiling positioning seat is installed on the vertical plate corresponding to the center position of the coiling station, coiling wheel assemblies which are arranged at intervals and used for limiting the running of the wire and are matched with the spring coiling positioning seat for coiling are installed at the circumferential position outside the discharging end of the spring coiling positioning seat, and a pitch pin assembly is installed in a gap between the upper end part of the discharging end of the guide rail and the spring coiling positioning seat, and a cutting-off knife is arranged right above the spring winding positioning seat.

6. The method for winding the compression spring with the prepressed end head according to claim 5 is characterized in that: the wire unwinding mechanism comprises a circular base, a liftable circular support plate is erected on the circular base, a rotary table is rotatably mounted on the circular support plate, a vertically-arranged unwinding shaft is mounted on the rotary table, a fixed sleeve is sleeved on the unwinding shaft, an arc-shaped top plate arranged on the circumference is arranged on the outer side of the fixed sleeve, the arc-shaped top plate is connected with the fixed sleeve through a guide rod, a jacking spring is sleeved on the guide rod between the arc-shaped top plate and the fixed sleeve, the circular support plate is lifted and lowered by a screw rod assembly below the circular support plate, the screw rod assembly comprises screw rods arranged at intervals on the circumference, the bottom end parts of the screw rods are rotatably mounted on the circular base, the upper end parts of the screw rods are rotatably mounted on the top plate, spiral holes in sliding guide with the screw rods are formed in the periphery of the circular support plate, and driven gears are respectively mounted at the bottom end parts of the screw rods, the middle part of the round base is provided with a driving gear driven by a motor, and the driving gear is in transmission engagement with each driven gear.

7. The method for winding the compression spring with the prepressed end head according to claim 5 is characterized in that: the coiling wheel subassembly including mobilizable removal seat, the front end tip that removes the seat rotates installs the roating seat, motor drive is passed through in the rotation of roating seat, be provided with the ring gear on the roating seat, the output axle head of motor install with ring gear complex gear, fixed mounting has the connector in the roating seat, install the coiling wheel through the round pin axle on the connector, the cylinder drive at its rear is passed through in the removal of removing the seat.

8. The method for winding the compression spring with the prepressed end head according to claim 5 is characterized in that: the spring winding positioning seat comprises a fixed mounting plate fixedly connected with the vertical plate, a positioning boss is welded on the fixed mounting plate, and a notch is formed in the feeding end of the positioning boss.

9. The method for winding the compression spring with the prepressed end head according to claim 5 is characterized in that: the pitch pin assembly comprises a push rod which is arranged on a vertical plate and can move back and forth, a fixing hole is formed in the end portion of the push rod, a pitch pin is fixedly arranged in the fixing hole, a guide hole for guiding the push rod is formed in the vertical plate, and the push rod moves under the drive of an electric cylinder at the rear end of the push rod.

10. A detection method of a compression spring with a pre-pressing treatment end head based on the claim 1 is characterized by comprising the following steps:

in the production process, sampling detection is carried out on the steel pipe, whether the end gap meets the requirement is judged firstly, if the end gap meets the requirement, the prepressing angle is detected, and the end and the adjacent ring are tightly combined only if the two meet the requirement;

detecting the end gap: a feeler gauge with the thickness of 0.1mm is adopted to pass through the end of the spring, and the feeler gauge is qualified if the feeler gauge cannot pass through the end of the spring or has resistance when the feeler gauge passes through the end of the spring;

the prepressing angle detection method comprises the following steps:

s1, respectively plugging one side of a pressure sensing paper into a contact position of the top end of a compression spring and an adjacent ring and a contact position of the bottom end of the compression spring and the adjacent ring; the rest part is arranged between the first ring and the second ring which are adjacent to the corresponding end heads; the size of the pressure sensing paper is ensured to exceed the area of the top surface or the bottom surface of the spring;

s2, compressing the spring to an installation position H1 by using a force measuring machine, returning, and taking out the pressure sensing paper, wherein the pressure sensing paper is provided with a pressure mark curve;

s3, measuring the chord length L1 of the indentation, wherein D represents the spring middle diameter and L represents the chord length of the indentation according to a calculation formula theta (L/D) 180/2 pi;

calculating a compaction angle theta 1, wherein theta 1 is (L1/D) 180/2 pi, and if theta 1 is more than 36 degrees, the compaction angle theta 1 is qualified;

s4, repeating the step 1, compressing the spring to a maximum working position H2, returning, and taking out the sensing paper to measure the indentation chord length; if the indentation is continuous and has no fracture, directly measuring L2, calculating the compaction angle theta 2 according to the formula, wherein theta 2 is (L2/D) × 180/2 pi, and if theta 2 is more than 120 degrees, the compression angle theta 2 is qualified;

if the indentation is not in a continuous state and the middle is broken, respectively measuring chord lengths L3 and L4, calculating corresponding compaction angles theta 3 and theta 4 according to the formula,

θ 3 ═ L3/D180/2 pi, θ 4 ═ L4/D180/2 pi, and θ 3 > 12 ° and θ 4 > 100 ° were acceptable.

The technical field is as follows:

the invention relates to the field of spring production and processing, and mainly relates to a compression spring with a prepressing end and a winding and detecting method thereof.

Background art:

the compression spring (pressure spring) is a helical spring bearing pressure, its material cross-section is circular, and its compression spring is made into the form of cylinder, cone, middle convex and middle concave and small quantity of non-circular, etc., and between the coils of the compression spring a certain quantity of coils are setGapWhen the spring is subjected to external load, the spring contracts and deforms, and deformation energy is stored.

The valve spring generally adopts compression spring, and it can guarantee that the valve takes a seat in time and closely laminates, prevents that the valve from taking place to beat when the engine vibration, destroys its leakproofness. The installation pretightening force generated by pre-compression during the installation of the valve spring is used for overcoming the inertia force of the valve and the transmission parts thereof in the closing process of the valve, eliminating the clearance generated by the action of the inertia force among the transmission parts and realizing the function.

Compression springs (valve springs) of the existing structure are generally adjusted correspondingly according to spring pitches during machining, and corresponding accurate requirements are not met, so that the situation that the end heads are mainly compressed and not compressed in two forms exists, and if the end heads of the compression springs (valve springs) which continuously reciprocate in an engine are not compressed or the compressed area is too small, the springs are broken. Especially diesel engine springs with large stress.

The main reasons for this are that the end of the non-compressed spring end ring impacts the adjacent ring during the movement, and the end of the spring contacts the adjacent ring to form a point-to-surface contact during the movement when the compressed area is too small, thereby causing the spring to break.

The invention content is as follows:

the invention aims to make up for the defects of the prior art and provides a compression spring with a prepressing end and a winding and detection method thereof.

The invention is realized by the following technical scheme:

the utility model provides a compression spring that end adopts pre-compaction, its characterized in that: the spring comprises a spring body which is produced and processed by prepressing, wherein a gap d is formed between two end heads of the spring body and an adjacent ring corresponding to the spring body, and the size of a contact area between the end head and the adjacent ring is a pressing angle theta when the spring body is stressed and compressed; and the pressing angle theta is an included angle formed by an indentation curve generated at the contact position of the spring end and the adjacent ring and the central position of the radian when the sensing paper is used for measurement.

The clearance d is less than or equal to 0.1 mm.

When the pressing angle theta is stressed and compressed to different positions, the angle between the end of the pressing angle theta and the contact area of the adjacent ring is different, when the spring body is compressed to the installation position H1, the corresponding pressing angle theta 1 is larger than 36 degrees, and when the spring body is compressed to the maximum working position H2, the detected indentation curve on the sensing paper is continuous, and the formed angle theta 2 is larger than 120 degrees; the detected indentation curve on the sensing paper is discontinuous, and the formed two angles theta 3 is larger than 12 degrees and theta 4 is larger than 100 degrees.

The end head adopts a winding method of a prepressing compression spring, the spring body of the structure needs to give initial prepressing force in the end head winding process, the pitch of the spring body in the winding process is adjusted in time, the axial movement of a corresponding winding wheel is adjusted at the same time, the contact area when the end head is tightly pressed with an adjacent ring is increased, and the spring end head is ensured to be in full contact with the adjacent ring and also exists after the two ends of the spring are ground;

the method comprises the following specific steps:

(1) setting target values of the pitch and the outer diameter winding of the spring, and adjusting the position of a corresponding winding roller on winding equipment according to the target values; meanwhile, the movement position of the corresponding pitch pin is adjusted according to the clearance d between the end head of the compression spring and the corresponding adjacent ring and the pitch required by the spring;

(2) the wire material is unreeled through the unreeling mechanism, and the end part of the wire material sequentially passes through the feeding roller and the guide plate and is fed into the reeling mechanism; in order to ensure that the pressing angle theta meets the requirement during winding, the pitch of the end head and the adjacent ring is controlled through a pitch pin, and the axial movement of the winding rollers is adjusted and controlled at the same time, so that a certain angle is formed between the upper winding roller and the lower winding roller in the axial direction, the angle is 12-45 degrees, and the pre-pressure generated by winding enables a larger contact area to be generated between the end head and the adjacent ring, so that the indentation effect of the adjacent ring and the end head is ensured, and the pressing angle theta is ensured;

(3) after the end coiling, require the position of equipment automatic adjustment pitch round pin according to the pitch of the spring body that corresponds, at this moment, for guaranteeing the pre-compaction effect of adjacent circle and end, there are two kinds of schemes:

the first is that the angle formed by the winding roller in the axial direction does not need to be restored in the process, so that the continuous winding is ensured until the prepressing is always existed in the process of the tail end of the spring, and after the tail end is wound, the cutting knife cuts off the material, so that the continuous winding of the spring body with the axial spiral offset and the prepressing of the whole spring can be obtained;

and secondly, after the winding of the end and the adjacent coil is finished, the axial angle of the winding roller is immediately recovered, the middle section of the spring body can be wound after the axial angle is recovered, after the winding of the middle section meets the corresponding requirement, the axial motion of the winding roller is adjusted and controlled again, so that the upper winding roller and the lower winding roller form a certain angle in the axial direction, the angle is 12-45 degrees, the winding with pre-pressure between the tail end and the adjacent coil is realized, after the winding of the tail end, the cutting knife cuts off the material, the pre-pressure between the end with two ends and the adjacent coil can be obtained, and the middle section of the spring body is normally wound.

The end head adopts a winding method of a compression spring through prepressing treatment, the winding device comprises a workbench, a vertical plate is erected on the workbench, a feeding station and a winding station are sequentially arranged on the vertical plate, the feeding end of the workbench is an unwinding station, a wire unwinding mechanism is installed on the unwinding station, upper and lower rows of rolling conveying wheels arranged in an array manner at intervals are distributed on the vertical plate corresponding to the feeding station, a guide rail for stabilizing the discharging direction and position of a wire is installed at the discharging end of each rolling conveying wheel through an installation seat, a spring winding positioning seat is installed on the vertical plate corresponding to the center position of the winding station, winding wheel assemblies which are arranged at intervals and used for limiting the wire to run and are matched with the spring winding positioning seat to wind are installed at the circumferential position outside the discharging end of the spring winding positioning seat, and a pitch pin assembly is installed in a gap between the upper end part of the guide rail and the spring winding positioning seat, and a cutting-off knife is arranged right above the spring winding positioning seat.

The wire unwinding mechanism comprises a circular base, a liftable circular support plate is erected on the circular base, a rotary table is rotatably mounted on the circular support plate, a vertically-arranged unwinding shaft is mounted on the rotary table, a fixed sleeve is sleeved on the unwinding shaft, an arc-shaped top plate arranged on the circumference is arranged on the outer side of the fixed sleeve, the arc-shaped top plate is connected with the fixed sleeve through a guide rod, a jacking spring is sleeved on the guide rod between the arc-shaped top plate and the fixed sleeve, the circular support plate is lifted and lowered by a screw rod assembly below the circular support plate, the screw rod assembly comprises screw rods arranged at intervals on the circumference, the bottom end parts of the screw rods are rotatably mounted on the circular base, the upper end parts of the screw rods are rotatably mounted on the top plate, spiral holes in sliding guide with the screw rods are formed in the periphery of the circular support plate, and driven gears are respectively mounted at the bottom end parts of the screw rods, the middle part of the round base is provided with a driving gear driven by a motor, and the driving gear is in transmission engagement with each driven gear.

The coiling wheel subassembly including mobilizable removal seat, the front end tip that removes the seat rotates installs the roating seat, motor drive is passed through in the rotation of roating seat, be provided with the ring gear on the roating seat, the output axle head of motor install with ring gear complex gear, fixed mounting has the connector in the roating seat, install the coiling wheel through the round pin axle on the connector, the cylinder drive at its rear is passed through in the removal of removing the seat.

The spring winding positioning seat comprises a fixed mounting plate fixedly connected with the vertical plate, a positioning boss is welded on the fixed mounting plate, and a notch is formed in the feeding end of the positioning boss.

The pitch pin assembly comprises a push rod which is arranged on a vertical plate and can move back and forth, a fixing hole is formed in the end portion of the push rod, a pitch pin is fixedly arranged in the fixing hole, a guide hole for guiding the push rod is formed in the vertical plate, and the push rod moves under the drive of an electric cylinder at the rear end of the push rod.

The end head adopts a detection method of a compression spring subjected to prepressing treatment, and the detection method comprises the following steps:

in the production process, sampling detection is carried out on the steel pipe, whether the end gap meets the requirement is judged firstly, if the end gap meets the requirement, the prepressing angle is detected, and the end and the adjacent ring are tightly combined only if the two meet the requirement;

detecting the end gap: a feeler gauge with the thickness of 0.1mm is adopted to pass through the end of the spring, and the feeler gauge is qualified if the feeler gauge cannot pass through the end of the spring or has resistance when the feeler gauge passes through the end of the spring;

the prepressing angle detection method comprises the following steps:

s1, respectively plugging one side of a pressure sensing paper into a contact position of the top end of a compression spring and an adjacent ring and a contact position of the bottom end of the compression spring and the adjacent ring; the rest part is arranged between the first ring and the second ring which are adjacent to the corresponding end heads; the size of the pressure sensing paper is ensured to exceed the area of the top surface or the bottom surface of the spring;

s2, compressing the spring to an installation position H1 by using a force measuring machine, returning, and taking out the pressure sensing paper, wherein the pressure sensing paper is provided with a pressure mark curve;

s3, measuring the chord length L1 of the indentation, wherein D represents the spring middle diameter and L represents the chord length of the indentation according to a calculation formula theta (L/D) 180/2 pi;

calculating a compaction angle theta 1, wherein theta 1 is (L1/D) 180/2 pi, and if theta 1 is more than 36 degrees, the compaction angle theta 1 is qualified;

s4, repeating the step 1, compressing the spring to a maximum working position H2, returning, and taking out the sensing paper to measure the indentation chord length; if the indentation is continuous and has no fracture, directly measuring L2, calculating the compaction angle theta 2 according to the formula, wherein theta 2 is (L2/D) × 180/2 pi, and if theta 2 is more than 120 degrees, the compression angle theta 2 is qualified;

if the indentation is not in a continuous state and the middle is broken, respectively measuring chord lengths L3 and L4, calculating corresponding compaction angles theta 3 and theta 4 according to the formula,

θ 3 ═ L3/D180/2 pi, θ 4 ═ L4/D180/2 pi, and θ 3 > 12 ° and θ 4 > 100 ° were acceptable.

The principle is as follows: because the end of the spring needs to be completely compressed, the contact area between the end and the adjacent ring is enlarged in a larger range, the overall performance of the spring is improved, a certain pre-pressure must be applied to the spring, and the end of the spring is ensured to be in full contact with the adjacent ring and also exist after the two ends of the spring are ground.

Since the initial preload of the spring cannot be quantified, two result parameters are introduced to determine whether the preload of the spring is sufficient (whether the head is tight). The end gap d represents the gap between the spring end and the adjacent ring; the compression angle theta indicates the size of the contact area between the end and the adjacent ring when the spring is stressed and compressed to a specified position, and the setting of the parameter can ensure that the end of the spring is in full contact with the adjacent ring and also exists after the two ends of the spring are ground, so that the situation that the end ring is broken easily after the spring is stressed and compressed is avoided, and the quality and the use requirement of the spring are improved.

The invention has the advantages that:

according to the invention, the spring structure is improved, so that the spring end is ensured to be in full contact with the adjacent ring and also exists after the two ends of the spring are ground, the situation that the tail ring is easy to break after the spring is stressed and compressed is avoided, and the quality and the use requirement of the spring are improved.

Description of the drawings:

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural view of fig. 1 from another angle.

Fig. 3 is a schematic structural view of the winding apparatus.

Fig. 4 is a schematic structural view of the spring winding positioning seat.

Fig. 5 is a schematic structural view of the wire unwinding mechanism.

Fig. 6 is a schematic structural view of an indentation curve corresponding to detection of the sensing paper when the spring body is compressed to the installation position.

Fig. 7 is a schematic structural view of a continuous indentation curve corresponding to sensing paper detection when the spring body is compressed to the maximum working position.

Fig. 8 is a schematic structural view of a discontinuous indentation curve corresponding to sensing paper detection when the spring body is compressed to the maximum working position.

Reference numerals:

1. a spring body; 2. a tip; 3. winding equipment; 4. a wire unwinding mechanism; 3-1, a workbench; 3-2, standing a plate; 3-3, rolling a conveying wheel; 3-4, a guide rail; 3-5, winding a positioning seat by using a spring; 3-6, winding a wheel assembly; 3-7, a pitch pin assembly; 3-8, cutting off the cutter; 4-1, a round base; 4-2, a circular support plate; 4-3, unwinding a reel; 4-4, a screw rod; 4-5, a top plate; 4-6, driven gear; 4-7, a driving gear; 4-8, fixing the sleeve; 4-9, arc top plate; 4-10, a guide rod; 4-11, pressing the spring tightly; 5. fixing the mounting plate; 6. positioning the boss; 7. a notch; 8. sensing paper; 9. a movable seat; 10. a rotating base; 11. a connector; 12. a winding wheel; .

The specific implementation mode is as follows:

see the drawings.

A compression spring for ensuring a tight clearance between an end head and an adjacent ring comprises a spring body 1 which is produced and processed by prepressing, a clearance d exists between two end heads of the spring body 1 and the adjacent ring corresponding to the end head, and the size of a contact area between the end head and the adjacent ring is a compression angle theta when the spring body 1 is compressed under stress; and the pressing angle theta is an included angle formed by an indentation curve generated at the contact position of the spring end and the adjacent ring and the central position of the radian when the sensing paper is used for measurement.

Furthermore, the clearance d is less than or equal to 0.1 mm. When the pressing angle theta is stressed and compressed to different positions, the angle between the end of the pressing angle theta and the contact area of the adjacent ring is different, when the spring body is compressed to the installation position H1, the corresponding pressing angle theta 1 is larger than 36 degrees, and when the spring body is compressed to the maximum working position H2, the detected indentation curve on the sensing paper is an angle theta 2 larger than 120 degrees formed by the continuous indentation curve; the detected indentation curve on the sensing paper is discontinuous, and the formed two angles theta 3 is larger than 12 degrees and theta 4 is larger than 100 degrees.

Further, the spring body 1 with the structure needs to give initial pre-pressure in the winding process, the pitch of the spring body 1 in the winding process is adjusted in time, and the end of the spring is ensured to be in full contact with an adjacent ring and to exist at the same time after the two ends of the spring are ground;

the method comprises the following specific steps:

(1) setting target values of the pitch and the outer diameter winding of the spring, and adjusting the position of a corresponding winding roller on winding equipment according to the target values; meanwhile, the movement position of the corresponding pitch pin is adjusted according to the clearance d between the end head of the compression spring and the corresponding adjacent ring and the pitch required by the spring;

(2) machining of front end of spring

The wire material is unreeled through the unreeling mechanism, and the end part of the wire material sequentially passes through the feeding roller and the guide plate and is fed into the reeling mechanism; in order to ensure that the pressing angle theta meets the requirement during winding, the pitch of the end head and the adjacent ring is controlled through a pitch pin, and the axial movement of the winding rollers is adjusted and controlled at the same time, so that a certain angle is formed between the upper winding roller and the lower winding roller in the axial direction, the angle is 12-45 degrees, and the pre-pressure generated by winding enables a larger contact area to be generated between the end head and the adjacent ring, so that the indentation effect of the adjacent ring and the end head is ensured, and the pressing angle theta is ensured;

(3) after the end coiling, require the position of equipment automatic adjustment pitch round pin according to the pitch of the spring body that corresponds, at this moment, for guaranteeing the pre-compaction effect of adjacent circle and end, there are two kinds of schemes:

the first is that the angle formed by the winding roller in the axial direction does not need to be restored in the process, so that the continuous winding is ensured until the prepressing is always existed in the process of the tail end of the spring, and after the tail end is wound, the cutting knife cuts off the material, so that the continuous winding of the spring body with the axial spiral offset and the prepressing of the whole spring can be obtained;

and secondly, after the winding of the end and the adjacent coil is finished, the axial angle of the winding roller is immediately recovered, the middle section of the spring body can be wound after the axial angle is recovered, after the winding of the middle section meets the corresponding requirement, the axial motion of the winding roller is adjusted and controlled again, so that the upper winding roller and the lower winding roller form a certain angle in the axial direction, the angle is 12-45 degrees, the winding with pre-pressure between the tail end and the adjacent coil is realized, after the winding of the tail end, the cutting knife cuts off the material, the pre-pressure between the end with two ends and the adjacent coil can be obtained, and the middle section of the spring body is normally wound.

Further, the winding device 3 comprises a workbench 3-1, a vertical plate 3-2 is erected on the workbench 3-1, a feeding station and a winding station are sequentially arranged on the vertical plate 3-2, a feeding end of the workbench is an unwinding station, a wire unwinding mechanism 4 is installed on the unwinding station, upper and lower rows of rolling conveying wheels 3-3 arranged in an array at intervals are distributed on the vertical plate 3-2 corresponding to the feeding station, a guide rail 3-4 for stabilizing the discharging direction and position of a wire is installed at the discharging end of the rolling conveying wheel 3-3 through an installation seat, a spring winding positioning seat 3-5 is installed on the vertical plate corresponding to the center position of the winding station, wheel assemblies 3-6 which are arranged at intervals and are used for limiting the running of the wire and are matched with the spring winding positioning seat for winding are installed on the circumferential position outside the discharging end of the spring winding positioning seat 3-5, a pitch pin assembly 3-7 is arranged in a gap between the upper end part of the discharging end of the guide rail 3-4 and the spring winding positioning seat 3-5, and a cutting knife 3-8 is arranged right above the spring winding positioning seat.

The spring winding positioning seat 3-5 comprises a fixed mounting plate 5 fixedly connected with the vertical plate 3-2, a positioning boss is welded on the fixed mounting plate 5, and a notch 7 is formed in the feeding end of the positioning boss 6. The pitch pin assemblies 3-7 comprise push rods which are arranged on a vertical plate and can move back and forth, fixing holes are formed in the end portions of the push rods, pitch pins are fixedly arranged in the fixing holes, guide holes for guiding the push rods are formed in the vertical plate, and the push rods are driven to move through electric cylinders at the rear ends of the push rods.

The winding wheel assembly 3-6 comprises a movable moving seat 9, a rotating seat 10 is installed at the end part of the front end of the moving seat 9 in a rotating mode, the rotating seat 10 is driven by a motor, a gear ring is arranged on the rotating seat 10, a gear matched with the gear ring is installed at the end of an output shaft of the motor, a connector 11 is fixedly installed in the rotating seat 10, a winding wheel 12 is installed on the connector 11 through a pin shaft, and the moving seat 10 is moved by a cylinder at the rear of the moving seat.

Further, the wire unwinding mechanism 4 comprises a circular base 4-1, a liftable circular support plate 4-2 is erected on the circular base 4-1, a rotary table is rotatably mounted on the circular support plate 4-2, a vertically placed unwinding shaft 4-3 is mounted on the rotary table, the circular support plate 4-2 is driven to ascend and descend by a screw rod assembly below the circular support plate, the screw rod assembly comprises screw rods 4-4 arranged at intervals circumferentially, the bottom end parts of the screw rods 4-4 are rotatably mounted on the circular base 4-1, the upper end parts of the screw rods 4-4 are rotatably mounted on a top plate 4-5, spiral holes in sliding guide with the screw rods 4-4 are formed in the periphery of the circular support plate 4-2, driven gears 4-6 are respectively mounted at the bottom end parts of the screw rods 4-4, and driving gears 4-7 driven by a motor are mounted in the middle part of the circular base 4-1, the driving gear 4-7 is in transmission engagement with each driven gear 4-6. The unwinding shaft 4-3 is sleeved with a fixed sleeve 4-8, the outer side of the fixed sleeve 4-8 is provided with an arc-shaped top plate 4-9 arranged circumferentially, the arc-shaped top plate 4-9 is connected with the fixed sleeve 4-8 through a guide rod 4-10, and a jacking spring 4-11 is sleeved on the guide rod 4-10.

Further, the detection method of the compression spring for ensuring the tight clearance between the end head and the adjacent ring comprises the following steps:

in the production process, sampling detection is carried out on the steel wire rope, whether the end gap meets the requirement is judged firstly, if the end gap meets the requirement, the prepressing angle is detected, and the end and the adjacent ring are tightly combined only if the two meet the requirement;

detecting the end gap: a feeler gauge with the thickness of 0.1mm is adopted to pass through the end of the spring, and the feeler gauge is qualified if the feeler gauge cannot pass through the end of the spring or has resistance when the feeler gauge passes through the end of the spring;

the prepressing angle detection method comprises the following steps:

s1, respectively plugging one side of a sensing paper 8-medium pressure (such as Fuji sensing paper FUJIFILM RRSCALE) into a contact part of the top end part of a compression spring and an adjacent ring and a contact part of the bottom end of the compression spring and the adjacent ring; the rest part is arranged between the first ring and the second ring which are adjacent to the corresponding end heads; the size of the pressure sensing paper is ensured to exceed the area of the top surface or the bottom surface of the spring;

s2, compressing the spring to an installation position H1 by using a force measuring machine, returning, and taking out the pressure sensing paper, wherein the pressure sensing paper is provided with a pressure mark curve;

s3, measuring the chord length L1 of the indentation, wherein D represents the spring middle diameter and L represents the chord length of the indentation according to a calculation formula theta (L/D) 180/2 pi;

calculating a compaction angle theta 1, wherein theta 1 is (L1/D) 180/2 pi, and if theta 1 is more than 36 degrees, the compaction angle theta 1 is qualified;

s4, repeating the step 1, compressing the spring to a maximum working position H2, returning, and taking out the sensing paper to measure the indentation chord length; if the indentation is continuous and has no fracture, directly measuring L2, calculating the compaction angle theta 2 according to the formula, wherein theta 2 is (L2/D) × 180/2 pi, and if theta 2 is more than 120 degrees, the compression angle theta 2 is qualified;

if the indentation is not in a continuous state and the middle is broken, respectively measuring chord lengths L3 and L4, calculating corresponding compaction angles theta 3 and theta 4 according to the formula,

θ 3 ═ L3/D180/2 pi, θ 4 ═ L4/D180/2 pi, and θ 3 > 12 ° and θ 4 > 100 ° were acceptable.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.