Guide device for a belt of a conical pulley belt transmission

Abstract

A guide device manufactured in a plastic injection molding process for a belt means of a conical pulley belt transmission, comprising two spaced-apart guide sections between which the belt means can be guided and at least one web section with an inner side and an outer side for connecting the guide sections, in which the at least one web section has at least one stiffening rib on the inside in order to structurally and / or functionally improve the guide device.

Description

[0001] The invention relates to a guide device produced in a plastic injection molding process for a belt means of a conical pulley belt transmission, comprising two spaced-apart guide sections between which the belt means can be guided and at least one web section with an inner side and an outer side for connecting the guide sections, in which the at least one web section has at least one stiffening rib on the inside in order to improve the guide device structurally and / or functionally.

[0002] From the German patent application DE 10 2013 213 163 A1 a guide device is known for a belt means of a conical pulley belt transmission having two spaced-apart guide sections, between which the belt means can be guided in a running direction, wherein the guide device is composed of a first half and a second half, in which, to prevent incorrect assembly, the first half has at least one first profile section and the second half has at least one second profile section geometrically complementary to the at least one first profile section.

[0003] The publications DE 10 2011 075 155 A1 and DE 100 47 840 A1 show further guide components for belting devices.

[0004] The invention is based on the object of structurally and / or functionally improving a guide device mentioned at the outset. In particular, sufficient flexural rigidity should be ensured. In particular, flexural rigidity should be increased. In particular, sufficient vibration damping properties should be ensured. In particular, tool tuning should be made easier. In particular, the number of correction loops required during tool tuning should be reduced. In particular, cooling should be evened out during production. In particular, an internal contact surface with a tool should be enlarged. In particular, installation space utilization should be improved. In particular, guidance of the belt means should be improved. In particular, acoustics during operation of the conical pulley belt transmission should be improved.

[0005] The object is achieved by a guide device produced in a plastic injection molding process for a belt means of a conical pulley belt transmission having two spaced-apart guide sections between which the belt means can be guided and at least one web section with an inner side and an outer side for connecting the guide sections, in which the at least one web section has at least one stiffening rib on the inside, wherein the at least one stiffening rib has a contour adapted to the belt means on the belt means side.

[0006] The plastic can first be plasticized. The plastic can then be injected under pressure into an injection mold. The plastic can then return to a solid state in the mold through cooling and / or a crosslinking reaction. The mold can then be opened and the plastic removed as a workpiece. The mold can be multi-part. The mold can have a cavity. The cavity can have a surface that determines the shape and / or surface structure of the workpiece. During workpiece production, the tool can be colder than a plastic mass. The plastic mass can be cooled in the mold. The plastic mass can solidify when it reaches its freezing point. Cooling can be accompanied by volume shrinkage. Volume shrinkage can affect the dimensional accuracy and / or surface quality of the workpiece.To at least partially compensate for this shrinkage, a reduced pressure can be maintained even after the cavity has been filled, allowing plastic material to flow and compensate for shrinkage. This continued pressure can continue until a sealing point is reached, i.e., a sprue has solidified. The plastic material in the cavity can continue to cool during a residual cooling period until a core, the liquid core of the workpiece, has solidified and sufficient rigidity for demolding is achieved.

[0007] The gear ratio of the conical pulley belt transmission can be continuously variable. The conical pulley belt transmission can be a continuously variable transmission (CVT). The conical pulley belt transmission can be a variator transmission. The conical pulley belt transmission can be arranged in a drive train of a motor vehicle. The drive train can have an internal combustion engine, a friction clutch, the conical pulley belt transmission, and at least one drivable vehicle wheel. The conical pulley belt transmission can have a first pair of conical pulleys and a second pair of conical pulleys. The conical pulley pairs can have parallel axes of rotation. Each pair of conical pulleys can have an axially fixed conical pulley and an axially displaceable conical pulley. The axially displaceable conical pulleys of the conical pulley pairs can be displaceable in opposite directions.The first pair of conical pulleys can be driven by the internal combustion engine.

[0008] The at least one vehicle wheel can be driven by means of the second conical pulley pair. The belt transmission can serve to transmit mechanical power between the first conical pulley pair and the second conical pulley pair. The belt-driven conical pulley transmission can have a housing. The conical pulleys can be mounted in the housing.

[0009] The belt can be a traction device. The belt can be a chain. The belt can be a plate-link chain. The belt can have plates and thrust pieces. The thrust pieces can serve to couple the belt to the conical pulley pairs. The coupling between the thrust pieces and the conical pulley pairs can be force-fit, in particular friction-fit. The plates can serve to couple the thrust pieces. The belt can have a load side and a slack side between the conical pulley pairs. The belt can have running radii on the conical pulley pairs. The running radii of the belt can depend on the axial distances between the conical pulleys of the conical pulley pairs. The gear ratio of the conical pulley belt transmission can depend on the running radii of the belt.A change in the axial distances between the conical pulleys of the conical pulley pairs can cause a change in the gear ratio of the conical pulley belt transmission.

[0010] With the help of the guide device, the belt can be guided along a load side. With the help of the guide device, the belt can be guided along a slack side. The belt can be guided along the guide sections in a transverse direction. A transverse direction can be a direction perpendicular to the running direction of the belt and to the axes of rotation of the conical pulley pairs. The belt can be guided between the guide sections with at least approximately no play. The belt can slide along the guide sections during operation. On one guide section, the belt can be guided by its inner side. An inner side of the belt can be a side facing the axes of rotation of the conical pulley pairs. On the other guide section, the belt can be guided by its outer side.An outer side of the belt means can be a side facing away from the rotational axes of the conical pulley pairs. The belt means can be guided on the at least one web section. The belt means can be guided on the at least one web section in the direction of the rotational axes of the conical pulley pairs. An inner side of the at least one web section can be a side facing the belt means. An outer side of the at least one web section can be a side facing away from the belt means. The guide sections can be spaced apart from one another in the transverse direction. The first guide section and the second guide section can be arranged parallel to one another. The at least one web section can serve to connect the first guide section and the second guide section at a distance from one another.

[0011] The at least one stiffening rib can extend between the guide sections. The at least one stiffening rib can have a wall thickness that at least approximately corresponds to a wall thickness of the at least one web section. The at least one web section can have a plurality of stiffening ribs, each of which has a predetermined minimum distance from one another. The guide device can have an internal bending stiffness of > approximately 4 N / mm and / or an external bending stiffness of > approximately 3 N / mm. The guide device can have an internal bending stiffness of approximately 4 N / mm to approximately 5 N / mm and / or an external bending stiffness of approximately 3 N / mm to approximately 4 N / mm. The guide device can have an internal bending stiffness of, for example, approximately 4.38 N / mm and / or an external bending stiffness of, for example, approximately 3.41 N / mm.

[0012] The guide device can be composed of a first half and a second half, the first half forming a first part of the guide sections and the second half forming a second part of the guide sections. The first half can have a web section with at least one stiffening rib. The second half can have a web section with at least one stiffening rib. The first half and the second half can be connected to one another in a force-fitting, form-fitting, and / or material-fitting manner. The first half and the second half can form a guide channel for guiding the belt means. The guide channel can have a cross-section that corresponds to a cross-section of the belt means.

[0013] The guide device can have a joining plane extending in the running direction of the belt. The joining plane can be arranged perpendicular to the rotational axes of the conical pulleys. The halves can be connected to each other along the joining plane. The halves can each have a joining surface. The halves can be joined with their joining surfaces adjacent to each other.

[0014] The first guide section can be divided along the joining plane. The first guide section can be divided along the joining plane into a first part and a second part. The first part of the first guide section can be formed with the first half of the guide device. The second part of the first guide section can be formed with the second half of the guide device. The second guide section can be divided along the joining plane. The second guide section can be divided along the joining plane into a first part and a second part. The first part of the second guide section can be formed with the first half of the guide device. The second part of the second guide section can be formed with the second half of the guide device.

[0015] In summary, and expressed in other words, the invention thus results, among other things, in internal ribbing of a channel. The internal ribbing of the channel can be designed to allow for efficient cooling of an injection mold. The ribs can have approximately half the normal wall thickness and be spaced apart from each other so that the mold still remains thick enough. The contour of the ribs can correspond to the lateral contour of a chain. Any existing clearance between the chain and the mold can thus be utilized.

[0016] "May" refers in particular to optional features of the invention. Accordingly, there is always an embodiment of the invention that has the respective feature or features.

[0017] The guide device according to the invention ensures sufficient flexural rigidity. Bending rigidity is increased. Adequate vibration damping properties are ensured. Tool tuning is facilitated. Tool tuning reduces the number of required correction loops. Cooling is evened out during production. The internal contact surface with the tool is enlarged. Space utilization is improved. The guidance of the belt drive is improved. Acoustics during operation of the conical pulley belt drive are improved.

[0018] Exemplary embodiments of the invention are described in more detail below with reference to the figures. Further features and advantages will become apparent from this description. Specific features of these exemplary embodiments may represent general features of the invention. Features of these exemplary embodiments combined with other features may also represent individual features of the invention.

[0019] They show schematically and by way of example: Fig. 1 a continuously variable transmission with two pairs of conical pulleys, a chain and a guide rail, Fig. 2 one half of a guide rail for a continuously variable transmission with a web section with stiffening ribs in view from the inside, Fig. 3 one half of a guide rail for a continuously variable transmission with a web section with stiffening ribs in a sectional view in the direction of chain travel and Fig. 4 a section of a continuously variable transmission with a pair of conical pulleys and a guide rail composed of two halves with web sections with stiffening ribs.

[0020] Fig. Figure 1 shows a continuously variable transmission 100 with two conical pulley pairs 102, 104, a chain 106, and a guide rail 108. The conical pulley pair 102 can be driven by a motor vehicle internal combustion engine. An axis of rotation of the conical pulley pair 102 is designated 110. The direction of arrow a indicates a drive rotation direction. The conical pulley pair 104 can be drive-connected to drive wheels of the motor vehicle. An axis of rotation of the conical pulley pair 104 is designated 112. The chain 106 serves to transmit mechanical power between the conical pulley pair 102 and the conical pulley pair 104. In the figure, the chain 106 runs on the conical pulley pair 102 on a small radius and on the conical pulley pair 104 on a large radius. This results in a slow gear ratio.

[0021] The conical pulleys of the conical pulley pairs 102, 104 can each be moved relative to one another in the direction of the rotational axes. If the conical pulleys of a conical pulley pair 102, 104 are far apart from one another, the chain 106 runs on a small radius. If the conical pulleys of a conical pulley pair 102, 104 are close together, the chain 106 runs on a large radius. If the distance between the conical pulleys is increased, the running radius of the chain 106 shifts towards smaller radii. If the distance between the conical pulleys is reduced, the running radius of the chain 106 shifts towards larger radii. To change a gear ratio, the conical pulleys of the conical pulley pairs 102, 104 are adjusted in opposite directions so that the chain 106 remains pretensioned. When the gear ratio of the transmission 100 changes, the relative position between the chain 106 and the axes 110, 112 of the conical pulley pairs 102, 104 changes.

[0022] When driven in the direction of arrow a, the chain 106 runs in the direction of arrow b. The guide rail 108 is then arranged on a load strand of the chain 106. The guide rail 108 has an inner guide section 114 and an outer guide section 116. The guide sections 114, 116 are connected to one another by means of web sections, such as 118. The chain 106 is guided between the guide sections 114, 116 with only slight play. The guide rail 108 is arranged on a holding tube 120. The holding tube 120 is fixed to a housing of the gear unit 100 and is thus fixed in relation to the axes 110, 112 of the conical pulley pairs 102, 104. For arrangement on the holding tube 120, the guide rail 108 has a slot-like receptacle. During operation of the gear unit 100, vibrations can be induced in the chain 106 in a transverse direction c. The slot-like receptacle of the guide rail 108 extends in the direction of the arrow c.To enable a change in the position of the chain 106 when the gear ratio of the transmission 100 changes, the guide rail 108 is mounted on the support tube 120 so that it can rotate about a longitudinal axis of the support tube 120 and can be displaced in the direction of arrow c. The guide rail 108 is composed of two halves. The halves are each manufactured from a plastic material using an injection molding process and subsequently joined together.

[0023] Fig. 2 shows one half 200 of a guide rail for a continuously variable transmission with a web section 202 with stiffening ribs 204, 206, 208 in a view from the inside. Fig. 3 shows half 200 of the guide rail in a sectional view in the chain travel direction. The guide rail has an inner guide section with an inner guide surface for a chain of the transmission. The guide rail has an outer guide section with an outer guide surface for the chain. The guide rail is composed of two halves, such as half 200. Half 200 has an inner guide section 210. The inner guide section 210 of half 200 forms part of the inner guide section of the guide rail. Half 200 has an outer guide section 212. The outer guide section 212 of half 200 forms part of the outer guide section of the guide rail. The web section 202 connects the inner guide section 210 and the outer guide section 212 to one another. The guide sections 210, 212 are held spaced apart from one another by means of the web section 202.

[0024] The web section 202 is narrower at its end associated with the inner guide section 210 than at its end associated with the outer guide section 212. The stiffening ribs 204, 206, 208 are arranged on the outside of the web section 202. The stiffening ribs 204, 206, 208 each extend between the inner guide section 210 and the outer guide section 212. The stiffening ribs 204, 206, 208 diverge from the inner guide section 210 to the outer guide section 212 in accordance with the width of the web section 202. The stiffening ribs 204, 206, 208 are spaced apart from one another at such a distance that a tool between the stiffening ribs 204, 206, 208 has sufficient strength. The stiffening ribs 204, 206, 208 each have a wall thickness approximately corresponding to the wall thickness of the web section 202. The stiffening ribs 204, 206, 208 serve to guide the chain laterally.The stiffening ribs 204, 206, 208 each have a height profile such that a guide contour adapted to the chain is formed.

[0025] In the present case, the stiffening ribs 204, 206, 208 each have a height increasing from the outer guide section 212 to the inner guide section 210. In the present case, the web section 202 has three stiffening ribs 204, 206, 208.

[0026] For a force- and form-fitting connection with a corresponding half, half 200 has extensions 216, 218, recesses 220, 222, and a locking hook 224 on a connecting plane 214. Two halves, such as half 200, are joined to form a guide rail by inserting the extensions of one half into corresponding recesses of the other half and sliding the halves against each other in the connecting plane. Undercut sections of the extensions or recesses engage with each other and / or the halves lock together.

[0027] The 200 half is manufactured in one piece. The 200 half is made of a plastic, for example, polyamide, optionally with a filling. The 200 half is manufactured using an injection molding process. Furthermore, particular attention is drawn to Fig. 1 and the corresponding description.

[0028] Fig. Figure 4 shows a section of a continuously variable transmission 300 with a pair of conical pulleys and a guide rail 306 composed of two halves 302, 304 with web sections 308, 310 with stiffening ribs 312, 314. The guide rail 306 is arranged between the conical pulleys 316, 318. The guide rail 306 forms with its halves 302, 304 a guide channel 320. The guide channel 320 has a cross section that approximately corresponds to a cross section of a chain of the transmission 300. The guide rail 306 is arranged in the transmission 300 on a support tube 322. Furthermore, reference is made in particular to Fig. 1-3 and the corresponding description. List of reference symbols 100 gearboxes 102 pair of conical pulleys 104 pair of conical pulleys 106 Chain 108 Guide rail 110 axis of rotation 112 axis of rotation 114 Guide Section 116 Guide Section 118 footbridge section 120 holding tube 200 half 202 footbridge section 204 Stiffening rib 206 Stiffening rib 208 Stiffening rib 210 inner guide section 212 outer guide section 214 Connection level 216 extension 218 Extension 220 recess 222 recess 224 locking hooks 300 gearboxes 302 half 304 half 306 guide rail 308 footbridge section 310 footbridge section 312 stiffening ribs 314 stiffening ribs 316 conical disc 318 conical disc 320 guide channel 322 holding tube

Claims

[1] A guide device (108, 306) produced in a plastic injection molding process for a belt means (106) of a conical pulley belt transmission (100, 300) comprising two spaced-apart guide sections (114, 116, 210, 212) between which the belt means (106) can be guided and at least one web section (118, 202, 308, 310) with an inner side and an outer side for connecting the guide sections (114, 116, 210, 212), wherein the at least one web section (118, 202, 308, 310) has at least one stiffening rib (204, 206, 208) on the inside and the at least one stiffening rib (204, 206, 208) on the belt means side has a Wrapping means (106) has an adapted contour. [2] Guide device (108, 306) according to claim 1, characterized by that the at least one stiffening rib (204, 206, 208) extends between the guide sections (114, 116, 210, 212). [3] Guide device (108, 306) according to at least one of the preceding claims, characterized by that the at least one stiffening rib (204, 206, 208) has a wall thickness which corresponds at least approximately to a wall thickness of the at least one web section (118, 202, 308, 310). [4] Guide device (108, 306) according to at least one of the preceding claims, characterized by that the at least one web section (118, 202, 308, 310) has a plurality of stiffening ribs (204, 206, 208) which are each spaced apart by a predetermined minimum distance from one another. [5] Guide device (108, 306) according to at least one of the preceding claims, characterized by that the guide device (108, 306) has an internal bending stiffness > 4 N / mm and / or an external bending stiffness > 3 N / mm. [6] Guide device (108, 306) according to at least one of the preceding claims, characterized bythat the guide device (108, 306) is composed of a first half (200) and a second half, wherein the first half (200) forms a first part of the guide sections (114, 116, 210, 212) and the second half forms a second part of the guide sections (114, 116, 210, 212).

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