A mold for molding a gear

Abstract

The utility model discloses a mould for forming gear, including upper die structure and lower die structure, upper die structure includes upper forming part, a plurality of forming convex parts, and lower die structure includes bottom plate subassembly, fixed die plate subassembly and lifting plate, and fixed die plate subassembly is equipped with rotating chamber, and rotating chamber is equipped with helical tooth forming part in rotation, and helical tooth forming part includes helical tooth forming part, and fixed die plate subassembly is equipped with lower forming part in the center of rotating chamber, and lower forming part is equipped with slip hole along the axial penetration, and lower forming part is equipped with straight tooth forming part, and the slip hole is equipped with center hole forming part in sliding, and center hole forming part is equipped with slip hole rotation stop cooperation, and the bottom of center hole forming part is equipped with screw hole, and lifting plate is equipped with top rod and screw rod, and screw rod is equipped with screw hole thread cooperation, and fixed die plate subassembly is equipped with at least two bearings along the vertical direction between fixed die plate subassembly and helical tooth forming part. Have the effect that improve the demoulding efficiency of double gear, effectively prevent the breakage in the demoulding process of double gear.

Description

Technical Field

[0001] This utility model relates to the field of gear injection molding technology, and in particular to a mold for molding gears. Background Technology

[0002] like Figures 1-2 The image shows a double gear 7 product in the prior art. The double gear 7 includes a first gear part 71 and a second gear part 72 that are coaxially arranged and integrally injection molded. The outer ring of the first gear part 71 is provided with a helical tooth part 711, and the outer ring of the second gear part 72 is provided with a spur tooth part 721. A central hole 73 is provided through the center of the double gear 7, and the first gear part 71 has protrusions integrally formed on both sides of the central hole 73. The first gear part 71 has a channel 712 that passes through the protrusions. Several positioning holes 713 are provided circumferentially at intervals near the helical tooth part 711 of the first gear part 71. Currently, for this type of double gear 7, multiple inserts are usually added to the mold to assist in molding. However, injection molding and demolding are difficult, which reduces the production and processing efficiency of the product and urgently needs improvement. Utility Model Content

[0003] The purpose of this invention is to provide a mold for forming gears, which improves the demolding efficiency of double gears and effectively prevents damage during the demolding process.

[0004] The above-mentioned technical objective of this utility model is achieved through the following technical solution: A mold for forming gears includes an upper mold structure and a lower mold structure. The upper mold structure includes an upper forming part and a plurality of forming protrusions protruding from the bottom of the upper forming part. The lower mold structure includes a base plate assembly, a fixed template assembly, and a lifting plate. The fixed template assembly has a rotating chamber, and a helical gear forming part is rotatably arranged in the rotating chamber. The helical gear forming part includes a helical gear forming portion located on the inner ring. The fixed template assembly has a lower forming part fixedly arranged at the center of the rotating chamber. The lower forming part has a sliding hole extending through it along the axial direction. The top is provided with a straight tooth forming part, and a center hole forming part is slidably provided in the sliding hole. The center hole forming part is anti-rotationally engaged with the sliding hole. The bottom of the center hole forming part is provided with a threaded hole along the axial direction. Several push rods are fixedly provided on the lifting plate. The lower mold structure includes a motor. The side of the lower mold structure is provided with a trigger switch for sensing the height position of the lifting plate. The trigger switch is electrically connected to the motor. The output end of the motor is provided with a screw. The screw passes through the lifting plate and is threadedly engaged with the threaded hole of the center hole forming part. At least two bearings are provided vertically between the fixed template assembly and the oblique tooth forming part.

[0005] By adopting the above technical solution, the upper mold structure and the lower mold structure are interlocked to form the cavity for molding the double gear. The helical gear forming part is used to form the helical teeth, and the straight gear forming part is used to form the straight teeth. The forming protrusions form the positioning holes and channels. After the double gear is injection molded, the upper mold structure is opened, and the lifting plate drives the ejector rod upwards. At this time, the upper end of the ejector rod pushes the double gear upwards, and the bearings drive the helical gear forming part to rotate relative to the double gear, allowing the helical teeth of the double gear to separate from the helical gear forming part and be demolded. Multiple bearings cooperate with each other. It can improve the smoothness and concentricity of the rotation of the helical gear forming part, which is conducive to improving the integrity of the demolding of the double gear. At the same time, the trigger switch senses the lifting plate and controls the motor to rotate. The motor drives the screw to engage with the threaded hole, so that the center hole forming part slides downward in the sliding hole, realizing the separation of the center hole forming part from the double gear, reducing the adhesion force between the double gear and the lower mold structure, thereby improving the smoothness of the ejector rod to lift the double gear upward and the demolding rate. It has the effect of improving the demolding efficiency of the double gear and effectively preventing damage during the demolding process of the double gear.

[0006] A further feature of this invention is that the forming protrusion includes a first forming protrusion for forming a positioning hole and a second forming protrusion for forming a second forming channel.

[0007] A further feature of this invention is that the template assembly includes an upper template, a middle template, and a lower template; the bearing includes an upper bearing and a lower bearing; the upper bearing is embedded between the upper template and the middle template; the lower bearing is installed between the middle template and the lower template; and the upper bearing is rotatably sleeved on the top of the helical tooth forming part, while the lower bearing is rotatably sleeved on the bottom of the helical tooth forming part.

[0008] By adopting the above technical solution, the upper and lower bearings can simultaneously improve the rotational smoothness of the upper and lower ends of the helical gear forming part, facilitating the smooth demolding of the helical gear part of the double gear.

[0009] A further feature of this invention is that the bottom of the helical tooth forming part is provided with an anti-detachment part facing outward in the radial direction, the middle fixed template is provided with a bearing mounting groove corresponding to the lower bearing and communicating with the rotating chamber, the lower bearing is installed in the bearing mounting groove, and the anti-detachment part is anti-detached from the lower bearing in the axial direction.

[0010] By adopting the above technical solution, the anti-detachment part can effectively prevent the helical tooth forming part from detaching from the rotating cavity of the lower mold structure.

[0011] A further feature of this invention is that the lower fixed template has a through hole corresponding to the screw, a wear-resistant lubricating sleeve is fixedly installed in the through hole, and the screw is movably inserted into the wear-resistant lubricating sleeve.

[0012] By adopting the above technical solution, the wear-resistant lubricating sleeve can improve the smoothness of screw rotation.

[0013] A further feature of this invention is that a spring is provided inside the sliding hole, the spring is sleeved outside the screw, and one end of the spring elastically abuts against the bottom of the central hole forming part, while the other end of the spring elastically abuts against the lower fixed template.

[0014] By adopting the above technical solution, when the mold is closed, the lifting plate moves down, and at this time the spring assists in pushing the central hole forming part to lift up and reset.

[0015] A further feature of this invention is that the screw includes a smooth rod portion near the lifting plate and a threaded engagement portion near the center hole forming part, wherein the threaded engagement portion is threadedly engaged with the threaded hole.

[0016] By adopting the above technical solution, the outer wall of the smooth rod is smooth, the screw slides and rises in the lower mold structure, and the threaded part can be threadedly engaged with the threaded hole of the center hole forming part, so as to divide the function of the screw into zones.

[0017] A further feature of this invention is that the helical tooth forming part is coated with a polytetrafluoroethylene coating on the surface of the helical tooth forming portion.

[0018] By adopting the above technical solution, the polytetrafluoroethylene coating can improve the smoothness of demolding between the helical tooth section and the helical tooth forming section of the double gear.

[0019] A further feature of this invention is that a positioning part is provided at the bottom center of the upper molded part, and a positioning groove is provided at the top of the central hole molded part corresponding to the positioning part, and the positioning part is inserted into the positioning groove for positioning.

[0020] By adopting the above technical solution, the positioning between the upper molded part and the center hole molded part is more accurate in the molded state, ensuring the dimensional accuracy and uniformity of the double gear injection molding.

[0021] A further feature of this invention is that the cross-sections of both the sliding hole and the center hole forming part are square, so that the center hole forming part and the sliding hole are in a non-rotational fit.

[0022] In summary, this utility model has the following beneficial effects:

[0023] The design employs a helical gear forming part and a lower forming part within the lower mold structure. The lower forming part has a sliding hole at its bottom, within which a center hole forming part slides. The center hole forming part engages with the sliding hole to prevent rotation. A threaded hole is located at the bottom of the center hole forming part. Simultaneously, an ejector rod and a screw are mounted on the lifting plate of the lower mold structure. The screw engages with the threaded hole of the center hole forming part. During injection molding, the upper and lower mold structures snap together to form the cavity for the double gear. The helical gear forming part shapes the helical teeth, while the straight gear forming part shapes the straight teeth. A forming protrusion shapes the positioning holes and channels. After the double gear is injection molded, the upper mold structure is opened, and the lifting plate drives the ejector rod upwards. At this point, the upper end of the ejector rod pushes the double gear upwards. The bearing drives the helical gear forming part to rotate relative to the double gear, allowing the helical gear part of the double gear to separate from the helical gear forming part and be demolded. The cooperation of multiple bearings can improve the smoothness and concentricity of the rotation of the helical gear forming part, which is conducive to improving the integrity of the demolding of the double gear. At the same time, the trigger switch senses the lifting plate and controls the motor to rotate. The motor drives the screw to engage with the threaded hole, allowing the center hole forming part to slide downward in the sliding hole, realizing the separation of the center hole forming part from the double gear, reducing the adhesion force between the double gear and the lower mold structure, thereby improving the smoothness of the ejector rod lifting the double gear upward and the demolding speed. It has the effect of improving the demolding efficiency of the double gear and effectively preventing damage to the double gear during the demolding process. Attached Figure Description

[0024] Figure 1 This is a product diagram of a double gear in the prior art.

[0025] Figure 2 This is a utility model Figure 1 Another perspective.

[0026] Figure 3 This is a top view of the present invention.

[0027] Figure 4 This is a utility model Figure 3 A sectional view of section AA in the middle.

[0028] Figure 5 This is a utility model Figure 4 A magnified view of a portion of region C.

[0029] Figure 6 This is a utility model Figure 3 Sectional view of section BB.

[0030] Figure 7 This is a utility model Figure 6 A magnified view of a portion of region D.

[0031] In the diagram: 1. Upper mold structure; 11. Upper forming part; 111. First forming protrusion; 112. Second forming protrusion; 113. Positioning part; 2. Lower mold structure; 21. Base plate assembly; 22. Fixed template assembly; 220. Rotating chamber; 221. Upper fixed template; 222. Middle fixed template; 2221. Bearing mounting groove; 223. Lower fixed template; 2231. Through hole; 2232. Wear-resistant lubricating sleeve; 23. Lifting plate; 231. Ejector rod; 232. Screw; 2321. Smooth rod part; 2322. Thread. 24. Motor; 241. Trigger switch; 3. Helical gear forming part; 31. Helical gear forming part; 32. Anti-detachment part; 4. Lower forming part; 41. Sliding hole; 411. Spring; 42. Straight gear forming part; 5. Center hole forming part; 51. Threaded hole; 52. Positioning groove; 6. Bearing; 61. Upper bearing; 62. Lower bearing; 7. Double gear; 71. First gear part; 711. Helical gear part; 712. Channel; 713. Positioning hole; 72. Second gear part; 721. Straight gear part; 73. Center hole. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings.

[0033] A mold for forming gears, such as Figures 3-5 As shown, the system includes an upper mold structure 1 and a lower mold structure 2. The upper mold structure 1 includes an upper forming part 11 and several forming protrusions protruding from the bottom of the upper forming part 11. The lower mold structure 2 includes a base plate assembly 21, a fixed template assembly 22, and a lifting plate 23. The fixed template assembly 22 has a rotating chamber 220. A helical tooth forming part 3 is rotatably arranged in the rotating chamber 220. The helical tooth forming part 3 includes a helical tooth forming part 31 located in the inner ring. A lower forming part 4 is fixedly arranged in the center of the rotating chamber 220 in the fixed template assembly 22. A sliding hole 41 is provided through the lower forming part 4 axially. A straight tooth forming part 42 is provided at the top of the sliding hole 41. A central hole forming part 5 is slidably arranged in the sliding hole 41. Furthermore, the center hole forming part 5 and the sliding hole 41 are anti-rotationally engaged. The bottom of the center hole forming part 5 is provided with a threaded hole 51 along the axial direction. Several push rods 231 are fixed on the lifting plate 23. The lower mold structure 2 includes a motor 24. The side of the lower mold structure 2 is provided with a trigger switch 241 for sensing the height position of the lifting plate 23. The trigger switch 241 is electrically connected to the motor 24. The output end of the motor 24 is provided with a screw 232. The screw 232 passes through the lifting plate 23 and is threadedly engaged with the threaded hole 51 of the center hole forming part 5. At least two bearings 6 are provided in the vertical direction between the fixed template assembly 22 and the helical tooth forming part 3. In this embodiment, the lifting plate 23 is driven to move up and down by a hydraulic cylinder.

[0034] like Figures 3-5 and Figure 7As shown, the forming protrusion includes a first forming protrusion 111 for forming the positioning hole 713 and a second forming protrusion 112 for forming the second forming channel 712; the helical gear forming part 3 is coated with a polytetrafluoroethylene coating on the surface of the helical gear forming part 31, which can improve the demolding smoothness between the helical gear part 711 and the helical gear forming part 31 of the double gear 7; a positioning part 113 is provided at the bottom center of the upper forming part 11, and a positioning groove 52 is provided at the top of the center hole forming part 5 corresponding to the positioning part 113. The positioning part 113 and the positioning groove 52 are inserted and positioned, so that the positioning between the upper forming part 11 and the center hole forming part 5 is more accurate in the molded state, ensuring the dimensional accuracy and uniformity of the injection molding of the double gear 7; the cross-section of the sliding hole 41 and the center hole forming part 5 are both square, so that the center hole forming part 5 and the sliding hole 41 are anti-rotationally fitted.

[0035] like Figures 3-7As shown, the fixed template assembly 22 includes an upper fixed template 221, a middle fixed template 222, and a lower fixed template 223. The bearing 6 includes an upper bearing 61 and a lower bearing 62. The upper bearing 61 is embedded between the upper fixed template 221 and the middle fixed template 222, and the lower bearing 62 is installed between the middle fixed template 222 and the lower fixed template 223. The upper bearing 61 is rotatably sleeved on the top of the helical tooth forming part 3, and the lower bearing 62 is rotatably sleeved on the bottom of the helical tooth forming part 3. The upper bearing 61 and the lower bearing 62 can simultaneously raise the helical tooth forming part 3. The smooth rotation of the upper and lower ends facilitates the smooth demolding of the helical gear 711 of the double gear 7; the bottom of the helical gear forming part 3 is provided with an anti-detachment part 32 facing outward in the radial direction; the middle fixed template 222 is provided with a bearing 6 mounting groove 2221 corresponding to the lower bearing 62, which communicates with the rotating chamber 220; the lower bearing 62 is installed in the bearing 6 mounting groove 2221, and the anti-detachment part 32 and the lower bearing 62 are anti-detached in the axial direction, which can effectively prevent the helical gear forming part 3 from being removed from the rotating chamber 220 of the lower mold structure 2; the lower fixed template 223 is provided with an anti-detachment part 32 facing outward in the radial direction; the lower fixed template 223 is provided with an anti-detachment part 32 corresponding to the lower bearing 62, which communicates with the rotating chamber 220 of the lower mold structure 2; the lower fixed template 223 is provided with an anti-detachment part 32 corresponding to the lower bearing 62, which communicates with ... The screw 232 has a through hole 2231, and a wear-resistant lubricating sleeve 2232 is fixedly installed inside the through hole 2231. The screw 232 is movably inserted into the wear-resistant lubricating sleeve 2232. The wear-resistant lubricating sleeve 2232 can improve the smoothness of the screw 232's rotation. In this embodiment, the wear-resistant lubricating sleeve 2232 is made of polytetrafluoroethylene. A spring 411 is installed inside the sliding hole 41. The spring 411 is sleeved on the outside of the screw 232, and one end of the spring 411 elastically abuts against the bottom of the central hole forming part 5, while the other end of the spring 411 elastically abuts against the lower fixed template 22. 3. When the mold is closed, the lifting plate 23 moves down. At this time, the spring 411 assists in pushing the center hole forming part 5 to lift up and reset. The screw 232 includes a push rod 231 part near the lifting plate 23 and a threaded engagement part 2322 near the center hole forming part 5. The threaded engagement part 2322 is threadedly engaged with the threaded hole 51. The outer wall of the push rod 231 part is smooth. The screw 232 slides up and down in the lower mold structure 2. The threaded engagement part 2322 can be threadedly engaged with the threaded hole 51 of the center hole forming part 5, thus dividing the function of the screw 232.

[0036] The basic working principle of this utility model is as follows: A helical gear forming part 3 and a lower forming part 4 are provided in the lower mold structure 2. A sliding hole 41 is opened at the bottom of the lower forming part 4, and a center hole 73 forming part 5 is slidably arranged inside the sliding hole 41. The center hole 73 forming part 5 is anti-rotationally engaged with the sliding hole 41. A threaded hole 51 is opened at the bottom of the center hole 73 forming part 5. Simultaneously, a push rod 231 and a screw 232 are provided on the lifting plate 23 of the lower mold structure 2. The screw 232 is threadedly engaged with the threaded hole 51 of the center hole 73 forming part 5. During injection molding, the upper mold structure 1 and the lower mold structure 2 are engaged to form the cavity for forming the double gear 7. The helical gear forming part 31 is used to form the helical gear part 711, and the straight gear forming part 42 is used to form the straight gear part 721. The forming protrusion forms the positioning hole 713 and the channel 712. After the double gear 7 is injection molded, the upper mold structure 1 is opened, and the lifting plate 23 drives the push rod 231 to rise upwards. The upper end of rod 231 pushes the double gear 7 upward, and the bearing 6 drives the helical gear forming part 3 to rotate relative to the double gear 7, so that the helical gear part 711 of the double gear 7 can separate from the helical gear forming part 3 and be demolded. The multiple bearings 6 cooperate with each other to improve the smoothness and concentricity of the rotation of the helical gear forming part 3, which is conducive to improving the integrity of the demolding of the double gear 7. At the same time, the trigger switch 241 senses the lifting plate 23 and controls the motor 24 to rotate. The motor 24 drives the screw 232 to engage with the threaded hole 51, so that the forming part 5 of the center hole 73 slides downward in the sliding hole 41, realizing the separation of the forming part 5 of the center hole 73 from the double gear 7, reducing the adhesion force between the double gear 7 and the lower mold structure 2, thereby improving the smoothness of the push rod 231 in lifting the double gear 7 upward and the demolding speed. It has the effect of improving the demolding efficiency of the double gear 7 and effectively preventing damage to the double gear 7 during the demolding process.

[0037] The above description is only a preferred embodiment of the present utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present utility model patent application are included in the scope of the present utility model patent application.

Claims

1. A mold for forming gears, comprising an upper mold structure (1) and a lower mold structure (2), characterized in that: The upper mold structure (1) includes an upper forming part (11) and several forming protrusions protruding from the bottom of the upper forming part (11). The lower mold structure (2) includes a base plate assembly (21), a fixed template assembly (22), and a lifting plate (23). The fixed template assembly (22) has a rotating chamber (220). A helical tooth forming part (3) is rotatably arranged in the rotating chamber (220). The helical tooth forming part (3) includes a helical tooth forming part (31) located in the inner ring. The fixed template assembly (22) has a lower forming part (4) fixedly arranged in the center of the rotating chamber (220). The lower forming part (4) has a sliding hole (41) extending through it axially. The lower forming part (4) has a straight tooth forming part (42) at the top of the sliding hole (41). A center hole forming part (5) is slidably arranged in the sliding hole (41). The center hole forming part (5) is anti-rotationally engaged with the sliding hole (41). The bottom of the center hole forming part (5) is provided with a threaded hole (51) along the axial direction. Several push rods (231) are fixed on the lifting plate (23). The lower mold structure (2) includes a motor (24). The side of the lower mold structure (2) is provided with a trigger switch (241) for sensing the height position of the lifting plate (23). The trigger switch (241) is electrically connected to the motor (24). The output end of the motor (24) is provided with a screw (232). The screw (232) passes through the lifting plate (23). The screw (232) is threadedly engaged with the threaded hole (51) of the center hole forming part (5). At least two bearings (6) are provided vertically between the fixed template assembly (22) and the helical tooth forming part (3).

2. The mold for forming gears according to claim 1, characterized in that: The forming protrusion includes a first forming protrusion (111) for forming a positioning hole (713) and a second forming protrusion (112) for forming a second forming channel (712).

3. A mold for forming gears according to claim 1, characterized in that: The fixed template assembly (22) includes an upper fixed template (221), a middle fixed template (222), and a lower fixed template (223). The bearing (6) includes an upper bearing (61) and a lower bearing (62). The upper bearing (61) is embedded between the upper fixed template (221) and the middle fixed template (222), and the lower bearing (62) is installed between the middle fixed template (222) and the lower fixed template (223). The upper bearing (61) is rotatably sleeved on the top of the helical tooth forming part (3), and the lower bearing (62) is rotatably sleeved on the bottom of the helical tooth forming part (3).

4. A mold for forming gears according to claim 3, characterized in that: The bottom of the helical tooth forming part (3) is provided with an anti-detachment part (32) facing outward. The middle fixed template (222) is provided with a bearing (6) mounting groove (2221) corresponding to the lower bearing (62) and communicating with the rotating chamber (220). The lower bearing (62) is installed in the bearing (6) mounting groove (2221), and the anti-detachment part (32) and the lower bearing (62) are anti-detached in the axial direction.

5. A mold for forming gears according to claim 3, characterized in that: The lower fixed template (223) has a through hole (2231) corresponding to the screw (232), and a wear-resistant lubricating sleeve (2232) is fixed inside the through hole (2231). The screw (232) is movably inserted into the wear-resistant lubricating sleeve (2232).

6. A mold for forming gears according to claim 3, characterized in that: A spring (411) is provided inside the sliding hole (41). The spring (411) is sleeved on the outside of the screw (232), and one end of the spring (411) elastically abuts against the bottom of the center hole forming part (5), and the other end of the spring (411) elastically abuts against the lower fixed template (223).

7. A mold for forming gears according to claim 6, characterized in that: The screw (232) includes a top rod (231) part near the lifting plate (23) and a threaded engagement part (2322) near the center hole forming part (5), the threaded engagement part (2322) being threadedly engaged with the threaded hole (51).

8. A mold for forming gears according to claim 1, characterized in that: The helical tooth forming part (3) is coated with a polytetrafluoroethylene coating on the surface of the helical tooth forming part (31).

9. A mold for forming gears according to claim 1, characterized in that: The upper molded part (11) has a positioning part (113) protruding from the center bottom, and the top of the center hole molded part (5) has a positioning groove (52) corresponding to the positioning part (113), and the positioning part (113) is inserted into the positioning groove (52) for positioning.

10. A mold for forming gears according to claim 1, characterized in that: The cross-sections of the sliding hole (41) and the center hole forming part (5) are both square, so that the center hole forming part (5) and the sliding hole (41) are anti-rotationally fitted.

Images