Pulley and pulley production mold

Abstract

The utility model discloses a pulley and a pulley production die. The pulley comprises an injection molding wheel body, the injection molding wheel body is provided with a drum-shaped rolling surface, the rolling surface is provided with a highest line and a lower line, and a joint line of the injection molding wheel body is arranged at the lower line; the water gap of the injection molding wheel body is arranged on the lower line or the end face of the injection molding wheel body. The pulley production mold comprises a movable mold, the movable mold is provided with a first parting surface and a plurality of first cavities, the side wall of each first cavity is of a drum-shaped structure matched with the rolling surface, and the first parting surface is arranged corresponding to the lower line; the fixed mold is provided with a second parting surface and a plurality of second cavities, the fixed mold is provided with a plurality of feeding ports, the feeding ports are communicated with the second cavities, and the feeding ports are arranged corresponding to the water gaps. Compared with the prior art, according to the scheme, the pulley can be directly used after injection molding is completed, the work of polishing the peripheral face of the pulley to remove a joint line and a water gap is not needed, and therefore the machining procedures can be reduced, the machining cost can be reduced, and the production efficiency of a factory can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of pulleys, especially pulleys. Background Art

[0002] The pulley for structures such as doors and windows generally consists of a bearing body and an injection-molded wheel body. The outer peripheral surface of the injection-molded wheel body is generally drum-shaped. When contacting with the track, the main contact position is near the highest line of the outer peripheral surface of the injection-molded wheel body (the highest line is the connection line of the points on the outer peripheral surface of the pulley that are farthest from the central axis of the pulley).

[0003] In the prior art, the injection-molded wheel body is generally formed by one-time injection molding or two-time injection molding. The mold joint line and the sprue of the plastic structure on the outermost layer of the injection-molded wheel body are both set on the highest line of the injection-molded wheel body. Flash will appear at the mold joint line, affecting the appearance of the pulley and the normal rolling of the pulley. After the plastic structure on the outermost layer of the injection-molded wheel body is injection-molded, it is necessary to polish the outer peripheral surface of the pulley through equipment or manually to eliminate the mold joint line and the sprue, so as to avoid the adverse effects of the mold joint line and the sprue on the normal rolling of the pulley. The production process of the pulley is numerous, and the production time of the pulley is relatively long, which is not conducive to the rapid production of the factory and the reduction of production costs. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is: to provide a pulley to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0005] The solution of the utility model to solve its technical problem is:

[0006] A pulley, including an injection-molded wheel body. The peripheral surface of the injection-molded wheel body is set as a rolling surface. The rolling surface has a drum-shaped surface structure. The rolling surface is provided with a highest line and a lower line. The lower line is arranged at a position on the rolling surface away from the highest line. The mold joint line of the injection-molded wheel body is arranged on the lower line; the sprue of the injection-molded wheel body is arranged on the lower line or the end face of the injection-molded wheel body.

[0007] Through the above technical solution, compared with the prior art, this solution arranges the mold joint line and the sprue of the first injection part at a place far from the highest line. After the pulley is injection-molded, it can be directly used without the need to polish the outer peripheral surface of the pulley to remove the mold joint line and the sprue, so as to reduce the processing process, reduce the processing cost, and improve the production efficiency of the factory.

[0008] As a further improvement of the above technical solution, the sprue of the injection-molded wheel body is arranged on the end face of the injection-molded wheel body.

[0009] With the above technical solution, the sprue of the first injection-molded part is arranged on the end face of the injection-molded wheel body, which can avoid arranging the sprue on the rolling surface, thereby preventing the sprue from protruding higher than the highest line, and thus avoiding the influence of the sprue on the normal rolling of the pulley.

[0010] As a further improvement of the above technical solution, the injection-molded wheel body includes a first injection-molded part and a second injection-molded part. The second injection-molded part is arranged inside the first injection-molded part, and the first injection-molded part is fixedly connected to the second injection-molded part.

[0011] As a further improvement of the above technical solution, the first injection-molded part is an elastic member, and the second injection-molded part is a rigid member.

[0012] As a further improvement of the above technical solution, the second injection-molded part is provided with a connecting peripheral surface, and the connecting peripheral surface has a shape that is higher in the middle and lower at both ends.

[0013] With the above technical solution, by providing the second injection-molded part that is higher in the middle and lower at both ends, it can play a role in restricting the relative displacement of the second injection-molded part and the first injection-molded part in the axial direction of the pulley, thereby greatly avoiding the separation of the second injection-molded part and the first injection-molded part during the actual operation of the pulley, and effectively ensuring the normal use of the pulley.

[0014] As a further improvement of the above technical solution, the pulley further includes a bearing body, and the bearing body is fixedly connected to the injection-molded wheel body.

[0015] As a further improvement of the above technical solution, a connecting groove is provided on the outer peripheral surface of the bearing body, and a connecting protrusion is provided on the injection-molded wheel body. The connecting protrusion and the connecting groove are in snap-fit connection.

[0016] With the above technical solution, when the second injection-molded part is injection-molded, the bearing body needs to be placed in the second injection mold first. Since the bearing body is provided with a connecting groove, the plastic fills the connecting groove and naturally forms a connecting protrusion. The connecting protrusion and the connecting groove can improve the connection strength between the second injection-molded part and the bearing body, and also greatly avoid the relative displacement of the second injection-molded part and the bearing body in the axial direction of the pulley, so as to ensure the normal use of the pulley.

[0017] A pulley production mold for producing the pulley as described in any one of the above. The pulley production mold includes:

[0018] A moving mold, the moving mold is provided with a first parting surface and a plurality of first cavities. The side wall of the first cavity has a drum-shaped structure matching the rolling surface, and the first parting surface is correspondingly arranged with the lower line;

[0019] The fixed mold is provided with a second parting surface and a plurality of second cavities, the second cavities corresponding to the first cavities one by one. The fixed mold is provided with a plurality of feeding ports, the feeding ports corresponding to the second cavities one by one, the feeding ports being communicated with the second cavities, and the feeding ports being correspondingly arranged with the gates of the injection wheel body.

[0020] As a further improvement of the above technical solution, the fixed mold includes a main mold body and a plurality of insert bodies, the insert bodies being provided with feeding runners, the feeding runners being communicated with the feeding ports.

[0021] As a further improvement of the above technical solution, the numbers of the first cavities, the second cavities, the feeding ports, and the feeding runners are all set to be multiple, and the moving mold is provided with a communicating runner, the communicating runner communicating a plurality of the feeding runners.

[0022] The beneficial effects of the present utility model are: reducing the processing procedures, reducing the processing costs, and improving the production efficiency of the factory.

[0023] The present utility model is used in the technical field of pulleys. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly describe the drawings required for use in the description of the embodiments. Obviously, the described drawings are only a part of the embodiments of the present utility model, rather than all the embodiments. Those skilled in the art can also obtain other design solutions and drawings based on these drawings without creative efforts.

[0025] Figure 1 is the overall structural schematic diagram of the pulley in the embodiment of the present utility model;

[0026] Figure 2 is the exploded structural schematic diagram of the pulley in the embodiment of the present utility model;

[0027] Figure 3 is the partial structural schematic diagram of the moving mold of the pulley production mold in the embodiment of the present utility model;

[0028] Figure 4 is the partial structural schematic diagram of the fixed mold of the pulley production mold in the embodiment of the present utility model.

[0029] In the figure, 100 is an injection-molded wheel body; 110 is the first injection part; 111 is a rolling surface; 112 is the highest line; 113 is a lower line; 114 is a sprue; 120 is the second injection part; 121 is a connecting protrusion; 122 is a connecting peripheral surface; 200 is a bearing body; 210 is a connecting groove; 300 is a fixed mold; 310 is a second cavity; 320 is a second parting surface; 330 is an insert body; 340 is a main mold body; 400 is a moving mold; 410 is a first cavity; 420 is a first parting surface; 430 is a communicating runner. Detailed implementation mode

[0030] The concept, specific structure and technical effects of the present utility model will be clearly and completely described below in conjunction with the embodiments and the drawings, so as to fully understand the purpose, features and effects of the present utility model. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present utility model. In addition, all the connection / connection relationships mentioned in the text do not refer to the direct connection of components alone, but refer to the formation of a more optimal connection structure by adding or reducing connection accessories according to the specific implementation situation. Each technical feature in the present invention can be combined interactively without conflict.

[0031] Refer to Figures 1 to 4 , the pulley includes an injection-molded wheel body 100 and a bearing body 200.

[0032] Specifically, in this embodiment, the injection-molded wheel body 100 includes a second injection part 120 and a first injection part 110. The bearing body 200 is fixedly connected to the second injection part 120, and the second injection part 120 is fixedly connected to the first injection part 110.

[0033] The second injection part 120 and the first injection part 110 are respectively injection-molded using two sets of molds, that is, the pulley of this solution is manufactured by using a two-shot injection molding process.

[0034] A connecting groove 210 is machined on the outer peripheral surface of the bearing body 200 (i.e., the outer peripheral surface of the outer ring). The connecting groove 210 is a ring-shaped groove structure. In this embodiment, the number of the connecting grooves 210 is set to one. In other embodiments, the number of the connecting grooves 210 can also be set to two, three, etc. Those skilled in the art can select the number of the connecting grooves 210 according to actual needs.

[0035] In other embodiments, the connecting groove 210 may not be provided, and those skilled in the art can select whether to provide the connecting groove 210 on the bearing body 200 according to actual needs.

[0036] The second injection molding part 120 is formed by injection molding with a second injection mold. Specifically, in this embodiment, the second injection molding part 120 is made of a relatively hard PC material. In other embodiments, the second injection molding part 120 can also be set to other relatively hard plastic materials, and those skilled in the art can select the specific material of the second injection molding part 120.

[0037] A connecting protrusion 121 is provided on the inner peripheral surface of the second injection molding part 120. The shape of the connecting protrusion 121 matches that of the connecting groove 210. When the second injection molding part 120 is injection molded, the bearing body 200 needs to be placed in the second injection mold first. Since the bearing body 200 is provided with the connecting groove 210, the plastic fills the connecting groove 210 and the connecting protrusion 121 is naturally formed. The connecting protrusion 121 and the connecting groove 210 can improve the connection strength between the second injection molding part 120 and the bearing body 200, and can also largely prevent the second injection molding part 120 and the bearing body 200 from having relative displacement in the axial direction of the pulley, so as to ensure the normal use of the pulley.

[0038] Specifically, in this embodiment, the outer peripheral surface of the second injection molding part 120 is set as a connecting peripheral surface 122, and the connecting peripheral surface 122 is connected to the inner side wall of the first injection molding part 110. The connecting peripheral surface 122 has a structure that is higher in the middle and lower at both sides. Specifically, in this embodiment, the connecting peripheral surface 122 has a structure of the peripheral surface of a combined body formed by splicing two frustums of a cone. In other embodiments, the connecting peripheral surface 122 can also be set to have a structure of a drum-shaped surface, and those skilled in the art can select the structure of the connecting peripheral surface 122 according to actual needs.

[0039] By setting the second injection molding part 120 with a higher middle and lower sides, it can play a role in restricting the relative displacement of the second injection molding part 120 and the first injection molding part 110 in the axial direction of the pulley, thereby largely preventing the second injection molding part 120 and the first injection molding part 110 from separating during the actual process of the pulley, so as to effectively ensure the normal use of the pulley.

[0040] The second injection mold is a conventional injection mold. The inventive point of this solution does not lie in the second injection mold, so it will not be elaborated here.

[0041] The first injection molding part 110 is arranged outside the second injection molding part 120. The first injection molding part 110 is formed by injection molding with a first injection mold, and the second injection molding part 120 is fixedly connected to the first injection molding part 110. Specifically, in this embodiment, the first injection molding part 110 is a member with a certain elasticity and is made of TPU material. In other embodiments, the first injection molding part 110 can also be set to other materials, and those skilled in the art can select the material of the first injection molding part 110 according to actual needs.

[0042] The outer peripheral surface of the first injection part 110 is provided as a rolling surface 111, and the rolling surface 111 has a drum-shaped surface structure that is higher in the middle and lower on both sides. The rolling surface 111 is provided with a highest line 112 and two lower lines 113. The highest line 112 is the connection line of the points on the rolling surface 111 that are farthest from the central axis of the pulley. The lower line 113 is provided with a chamfered transition at the end face of the first injection part 110.

[0043] The distance from the highest line 112 to the central axis of the pulley is greater than the distance from the lower line 113 to the central axis of the pulley.

[0044] The two lower lines 113 are respectively arranged on both sides of the highest line 112. In this embodiment, the distances from the two lower lines 113 to the central axis of the pulley are equal. In other embodiments, the distances from the two lower lines 113 to the central axis of the pulley can also be set to be unequal, and those skilled in the art can select the distances from the two lower lines 113 to the central axis of the pulley according to actual needs.

[0045] The mold joint line of the first injection part 110 is arranged at one of the lower lines 113. Since the contact part between the pulley and the door and window track is at the highest line 112 and near the highest line 112, arranging the mold joint line of the first injection part 110 at the lower line 113 can avoid the influence of the mold joint line on the normal rolling of the pulley and ensure the smooth rolling of the pulley.

[0046] The sprue 114 of the first injection part 110 is arranged at the lower line 113 or the end face of the first injection part 110. Specifically, in this embodiment, the sprue 114 of the first injection part 110 is arranged at the end face of the injection wheel body 100. By arranging the sprue 114 of the first injection part 110 at the end face of the injection wheel body 100, it can be avoided that the sprue 114 is arranged on the rolling surface 111, thereby avoiding the sprue 114 protruding higher than the highest line 112, and thus avoiding the influence of the sprue 114 on the normal rolling of the pulley. In other embodiments, the sprue 114 of the first injection part 110 can also be arranged at the lower line 113, and those skilled in the art can select the position of the sprue 114 of the first injection part 110 according to actual needs.

[0047] In the prior art, in the solution of arranging the mold joint line and the sprue 114 at the highest line 112, after the pulley is demolded, it is necessary to polish the outer peripheral surface of the pulley to polish the mold joint line and the sprue 114 on the outer peripheral surface of the pulley to avoid the adverse effects of the sprue 114 and the mold joint line on the normal rolling of the pulley at the highest line 112. Compared with the prior art, in this solution, the mold joint line and the sprue 114 of the first injection part 110 are arranged at a place far from the highest line 112. After the pulley is injection-molded, it can be directly used without the need to polish the outer peripheral surface of the pulley to remove the mold joint line and the sprue 114, thereby reducing the processing procedures, reducing the processing cost, and improving the production efficiency of the factory.

[0048] The improvement points of this solution for the injection mold mainly focus on the first injection mold. The first injection mold will be described in detail below.

[0049] The first injection mold includes a fixed mold 300 and a movable mold 400, and the fixed mold 300 and the movable mold 400 can move relative to each other.

[0050] The movable mold 400 is provided with a first cavity 410 and a first parting surface 420. The number of the first cavities 410 is set to be multiple, and the multiple first cavities 410 are evenly arranged on the fixed mold 300. The side wall of the first cavity 410 has a drum-shaped structure, and the side wall of the first cavity 410 matches the rolling surface 111. The first parting surface 420 is correspondingly arranged with one of the lower lines 113.

[0051] The fixed mold 300 is provided with a second cavity 310 and a second parting surface 320. The number of the second cavities 310 is set to be multiple, and the multiple second cavities 310 are arranged in one-to-one correspondence with the multiple first cavities 410. The second parting surface 320 cooperates with the first parting surface 420 so that the first cavity 410 and the second cavity 310 form an injection cavity, and the first injection part 110 is injection-molded in the injection cavity. The fixed mold 300 is also provided with a plurality of feed ports, and the plurality of feed ports are arranged in one-to-one correspondence with the plurality of second cavities 310, and the feed ports are communicated with the end surfaces of the second cavities 310, so that the sprue 114 formed by the feed ports is arranged on the end surface of the first injection part 110. In other embodiments, the feed ports can also be arranged at positions corresponding to the lower lines 113 so that the sprue 114 formed by the feed ports is arranged near the lower lines 113, thereby avoiding the sprue 114 being arranged at the highest line 112.

[0052] The fixed mold 300 includes a plurality of insert bodies 330 and a main mold body 340. The plurality of insert bodies 330 are embedded and installed in the main mold body 340. A feed runner is provided on the side wall of the insert body 330. The total number of feed runners on the fixed mold 300 is the same as the total number of feed inlets on the fixed mold 300. The feed runners and the feed inlets are arranged in one-to-one correspondence and are interconnected with each other. The moving mold 400 is provided with a connecting runner 430, and the connecting runner 430 communicates with a plurality of feed runners.

[0053] The fixed mold 300 is provided with positioning rods. The positioning rods pass through the holes of the semi-finished bearing body 200 to position the semi-finished product.

[0054] The production process of the pulley in this solution is as follows:

[0055] First, injection molding is performed on the second injection part 120. Subsequently, the injection-molded semi-finished products are taken out and placed on the fixed mold 300 of the first injection mold one by one. Then, injection molding is performed on the first injection part 110. After the injection molding of the first injection part 110 is completed, the moving mold 400 moves away from the fixed mold 300. Since the first injection part 110 is an elastic member, when the moving mold 400 moves away from the fixed mold 300, the first injection part 110 may undergo a certain elastic deformation so that the first injection part 110 can be smoothly separated from the moving mold 400. Subsequently, the product is demolded. During the demolding process of the product, the feed inlet will be pulled off, causing the runner to be automatically separated from the pulley.

[0056] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Those skilled in the art can also make various equivalent variations or substitutions without departing from the spirit of the present invention. These equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A pulley, characterized in that: It includes an injection molding wheel body, the circumferential surface of the injection molding wheel body is set as a rolling surface, the rolling surface is a drum-shaped surface structure, the rolling surface is provided with a highest line and a lower line, the lower line is set at a position of the rolling surface away from the highest line, and the mold line of the injection molding wheel body is set at the lower line; the water inlet of the injection molding wheel body is set at the lower line or the end face of the injection molding wheel body.

2. The pulley according to claim 1, characterized in that: The water inlet of the injection wheel body is arranged on the end surface of the injection wheel body.

3. The pulley according to claim 1, characterized in that: The injection molding wheel body comprises a first injection molding part and a second injection molding part, wherein the second injection molding part is arranged inside the first injection molding part, and the first injection molding part is fixedly connected to the second injection molding part.

4. The pulley according to claim 3, characterized in that: The first injection-molded part is an elastic component, and the second injection-molded part is a hard component.

5. The pulley according to claim 3, characterized in that: The second injection molded part is provided with a connection peripheral surface, and the connection peripheral surface is in a shape of being high in the middle and low at both sides.

6. The pulley according to claim 1, characterized in that: The pulley further comprises a bearing body, and the bearing body is fixedly connected to the injection molded wheel body.

7. The pulley according to claim 6, characterized in that: The outer peripheral surface of the bearing body is provided with a connecting groove, and the injection wheel body is provided with a connecting protrusion, and the connecting protrusion and the connecting groove are snap-fitted.

8. Pulley production mold, characterized by: Used to produce the pulley according to any one of claims 1 to 7, the pulley production mold comprises: A movable mold, wherein the movable mold is provided with a first parting surface and a plurality of first cavities, the side walls of the first cavities are in a drum-shaped structure matching the rolling surface, and the first parting surface is arranged corresponding to the lower line; The fixed mold is provided with a second parting surface and a plurality of second cavities, the second cavities correspond one-to-one with the first cavities, the fixed mold is provided with a plurality of feed ports, the feed ports correspond one-to-one with the second cavities, the feed ports are connected with the second cavities, and the feed ports are arranged corresponding to the water inlets of the injection wheel body.

9. The pulley production mold according to claim 8, characterized in that: The fixed mold comprises a main mold body and a plurality of insert bodies, the insert bodies are provided with a feed flow channel, and the feed flow channel is communicated with the feed port.

10. The pulley production mold according to claim 9, characterized in that: The number of the first cavity, the second cavity, the feed port, and the feed channel are all set to be multiple, and the movable mold is provided with a connecting channel, and the connecting channel connects the multiple feed channels.

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