阅读说明：本技术 凸轮轴单元和用于制造凸轮轴单元的方法 (Camshaft unit and method for producing a camshaft unit ) 是由 比约恩·雅各布森 格哈德·布鲁姆 阿克谢尔·拉克内 维尔纳·哈伯斯 菲利普·伦德 于 2019-04-04 设计创作，主要内容包括：本发明涉及一种凸轮轴单元,其具有至少一个第一构件(14)和第二构件,其中,第一构件(14)具有第一密封面(40),第二构件具有第二密封面,并且其中,两个密封面(40)相互对置地布置,并且其中,密封元件(30)构造在两个密封面(40)之间。根据本发明,密封元件(30)在液态状态中可以施加到至少其中一个密封面(40)上,并且在组装两个构件(14)之前是可硬化的,其中,借助组装两个构件(14)可以获得其最终的形状。本发明此外还涉及用于制造凸轮轴单元的方法。(The invention relates to a camshaft unit having at least one first component (14) and a second component, wherein the first component (14) has a first sealing surface (40) and the second component has a second sealing surface, and wherein the two sealing surfaces (40) are arranged opposite one another, and wherein a sealing element (30) is formed between the two sealing surfaces (40). According to the invention, the sealing element (30) can be applied to at least one of the sealing surfaces (40) in the liquid state and can be hardened before the two components (14) are assembled, wherein the final shape thereof can be obtained by assembling the two components (14). The invention further relates to a method for producing a camshaft unit.)

1. Camshaft unit having at least one first component (14) and a second component, wherein the first component (14) has a first sealing surface (40) and the second component has a second sealing surface, and wherein the two sealing surfaces (40) are arranged opposite one another, and wherein a sealing element (30) is formed between the two sealing surfaces (40),

characterized in that the sealing element (30) can be applied to at least one of the sealing surfaces (40) in the liquid state and is hardenable before the two components (14) are assembled, wherein the final shape of the sealing element can be achieved by assembling the two components (14).

2. Camshaft unit according to claim 1, characterized in that the sealing element (30) is designed in the form of a force-dividing seal, wherein a receiving element (36) designed to receive the sealing element (30) is designed in the first sealing surface (40) and/or the second sealing surface.

3. Camshaft unit according to claim 2, characterized in that the receiving element (36) has a width (B1; B2) and a depth (T), wherein the width (B1; B2) is greater than the depth (T).

4. Camshaft unit according to one of the preceding claims, characterized in that the sealing element (30) is constructed in the form of a sprayed strip.

5. A camshaft unit as claimed in one of claims 2 to 4, characterized in that the sealing element (30) is configured in operation at a distance from the wall (44) of the receiving element (36).

6. Camshaft unit according to one of the preceding claims, characterized in that the sealing element (30) is hardenable by means of electromagnetic radiation.

7. Camshaft unit according to claim 6, characterized in that the electromagnetic radiation is configured by means of an ultraviolet radiation beam.

8. Camshaft unit according to one of the preceding claims, characterized in that the sealing element (30) is configured as a compression sealing element.

9. A camshaft unit as claimed in any one of the preceding claims, characterized in that the first and second members (14, 14) are each a member of a camshaft adjuster.

10. A method for producing a camshaft unit, wherein the camshaft unit (10) has at least one first component (14) and a second component, and wherein the first component (14) has a first sealing surface (40) and the second component has a second sealing surface, and wherein the two sealing surfaces (40) are arranged opposite one another,

characterized in that the seal between the two sealing surfaces (40) is formed by means of a sealing element (30) which can be applied to at least one of the sealing surfaces (40) in the liquid state, wherein the sealing element (30) assumes its final shape during the assembly of the two components (14).

11. Method according to claim 10, characterized in that in a first step the sealing element (30) is applied in a liquid state to at least one of the sealing surfaces (40), in a second step the sealing element (30) is hardened by means of electromagnetic radiation, and in a third step the sealing element (30) is compressed, wherein the two components are pressed against each other.

12. Method according to claim 10 or 11, characterized in that the sealing element (30) is constructed in a force shunt.

13. Method according to one of claims 10 to 12, characterized in that a receiving element (36) is introduced into a first component (14) having a first sealing surface (40) and a further receiving element is introduced into a second component having a second sealing surface, and in that a sealing element (30) is introduced into the receiving element (36) and a further sealing element is introduced into the further receiving element.

14. Method according to any one of claims 10 to 13, characterized in that the sealing element (30) and/or the further sealing element is applied to the first sealing surface (40) and/or the second sealing surface in an injection method.

15. The method according to any one of claims 11 to 14, characterized in that the hardening is caused by ultraviolet radiation of the sealing element (30).

Technical Field

The invention relates to a camshaft unit and a method for manufacturing the camshaft unit.

Background

Camshaft units for internal combustion engines are known. Camshaft units are basically camshafts of an internal combustion engine for controlling the intake and exhaust valves of the internal combustion engine, a camshaft adjuster for changing the position of the camshaft relative to the crankshaft of the internal combustion engine, and an actuator, which is usually a camshaft adjuster, for operating the camshaft adjuster. The camshaft unit has hydraulic fluid and is sealed at least from the environment, so that the hydraulic fluid flowing through the camshaft unit remains in a provided fluid circuit, which does not have to be closed forcibly. Depending on the construction of the camshaft unit, a seal may also be required inside the camshaft unit. In other words, a structural component or member is to be sealed with respect to another structural component or member.

For sealing, a shaped seal is preferably used, which in its initial state is generally of circular configuration. That is, the shaped seal must be brought into its profile during its assembly in the groove provided in the respective component. However, depending on its material properties, the formed seal has a tendency to return to its original shape again. During assembly, the shaped seal is brought into the groove by means of the slider. On account of the tendency of the shaped seal to return again to its original shape, the disadvantage is obtained during assembly that the shaped seal moves completely or partially out of the groove. This is limited only by the groove itself or by its walls. Depending on the positioning of the shaped seal, and possibly of further building elements, by means of the slider, the shaped seal is thus matched to the geometry of the groove slightly differently at a time. Unforeseen weaknesses of the seal can thereby be formed.

Furthermore, tilting of the formed seal due to loose, i.e. unsafe, movement into the groove or due to stresses in the material cannot be ruled out. This creates the risk that axial pretensioning forces act on the regions of the formed seal that are not provided for this purpose when fastening components with seals, for example in the case of a screw cap and a locking disk with a stator of a camshaft adjuster. Thereby, damage to the seal may result. Tilting and damage to the seal involve the risk that only after a longer load phase in the operation Of the internal combustion engine is a perceptible leakage Of hydraulic fluid, since tilting and/or damage may remain unrecognizable in the so-called End Of Line tightness test.

Disclosure of Invention

The object of the invention is to provide a camshaft unit with a better and cheaper seal. A further object is to specify a method for producing a camshaft unit.

This object is achieved according to the invention by a camshaft unit having the features of claim 1. The further object is achieved by a method having the features of claim 10. Further embodiments and suitable and important developments of the invention are specified in the respective dependent claims.

The camshaft unit according to the invention comprises at least one first and one second component. The first member has a first sealing surface and the second member has a second sealing surface. The two sealing surfaces are arranged opposite each other. A sealing element is formed between the two components and thus between the two sealing surfaces. According to the invention, the sealing element can be applied to at least one of the sealing surfaces in the liquid state and can be hardened before the two components are assembled, wherein the final shape can be obtained by means of the assembly of the two components. In other words, the sealing element is applied in liquid form and may subsequently be hardened before assembling the two components. And its final shape is obtained by means of assembly. The advantages can be seen in the possibility of precise positioning of the sealing element, since if the sealing element is applied to the sealing surface in precise dosing, the sealing element is precisely located at the position at which it is applied. In this case, the liquid form is understood to mean that the sealing element is made of a material whose surface stress inhibits a change in its shape in the applied state, in particular before hardening. Accurate positioning and shape retention thus eliminates, for example, tilting of the sealing element. Furthermore, an adhesive force acts between the sealing element and the sealing surface, which prevents the sealing element and the sealing surface from being released and therefore the situation in which the sealing element is lost before being interrupted by the second sealing surface can no longer occur.

In a further embodiment of the camshaft unit according to the invention, the sealing element is designed as a force-splitting seal, wherein the receiving element designed to receive the seal is designed in a first partial section of the first component having the first sealing surface and/or in a second partial section of the second component having the second sealing surface. The accommodation of the sealing element in the receiving element, which is preferably embodied in the form of a groove, supports the precise positioning of the sealing element and its resistance to detachment.

Preferably, the groove has a width and a depth, wherein the width is greater than the depth. Because there is adhesion between the sealing element and the sealing surface, in particular in its liquid state, and thus between the sealing element and the base or base of the receiving element, it is not necessary to construct the depth to be greater than the width for precise positioning and fixing of the sealing element, as is often required for shaped seals. This means in other words that the sealing element and the receiving element can also be formed on components having a small wall thickness. Furthermore, the compression limit of the material of the sealing element is greater and the sealing element can therefore be compressed more strongly. The width of the receiving element is therefore as large as possible, whereas the depth is configured as small as possible, in comparison with the prior art.

Advantageously, the sealing element is configured in the form of a sprayed strip. This is usually achieved in a robot-supported spraying method, whereby the strip can have a constant thickness or a constant diameter. A uniform strip and thus a uniform sealing element over its circumference can thereby be achieved.

In a further embodiment of the camshaft unit according to the invention, the sealing element is designed to bear against the wall of the receiving element at the highest during operation. The advantage is that, in the event of metal and/or plastic contact, the mutually opposite sealing surfaces of the components come to bear securely against one another in the region of the outer configuration of the receiving element, as a result of which a secure seal is obtained by means of the sealing element. If the sealing element can escape from the receiving element, in other words overflow, for example during compression of the sealing element on different areas, non-tightness is caused in the different areas due to the lack of contact between the two components. That is, the sealing element may expand during operation without causing the two sealing surfaces to disengage from their contact areas.

In a further embodiment of the camshaft unit according to the invention, the sealing element is hardenable by means of electromagnetic radiation. Electromagnetic radiation, for example infrared radiation or ultraviolet radiation, allows the sealing element to be hardened contactlessly and in a short time. The components hardened by means of ultraviolet radiation, in other words by means of ultraviolet radiation, have in particular a high lifetime.

In a further embodiment of the camshaft unit according to the invention, the sealing element is configured as a compression sealing element. This means that the sealing action of the sealing element is only produced by compression. Here, as a compression sealing element, a certain linear compression (Stauchung) of the sealing element in the receiving element is required in order to achieve a sufficiently large sealing action in the loaded state.

The camshaft unit according to the invention has a high long-term stability of the seal on the basis of the sealing element. In particular, the possibility of using sealing elements made of polyacrylate leads to a high long-term stability, in particular with respect to engine oil, and over a wide temperature range.

A second aspect of the invention relates to a method for producing a camshaft unit, wherein the camshaft unit has at least one first component and a second component, and wherein the first component comprises a first sealing surface and the second component comprises a second sealing surface, and wherein the two sealing surfaces are arranged opposite one another. According to the invention, the seal between the two sealing surfaces is formed by means of a sealing element which is applied to at least one of the sealing surfaces in the liquid state, wherein the sealing element assumes its final shape during the assembly of the two components. The advantage of this method is the precise positioning of the sealing element and the elimination of the detachment of the sealing element during assembly based on the adhesion between the sealing face and the sealing element.

In a further embodiment of the method according to the invention, the sealing element is applied to at least one of the sealing surfaces in the liquid state in a first step. In a second step, the sealing element is hardened by means of electromagnetic radiation, and in a third step, the sealing element is compressed, wherein the two components are pressed against one another. The properties of the metered sealing element, as are possible on account of the application of the sealing element in the liquid state, result in a significant increase in process safety during the assembly of the camshaft unit. This results in a reduction in production costs. The sealing element can advantageously be controlled according to the second step, since the assembly of the component is not carried out until after hardening. In this case, defective sealing elements can be easily identified. The sealing element is removed and a new sealing element can be installed. That is to say that a defective camshaft unit is not provided because of a defective sealing element, so that the so-called warranty and reputation costs are also significantly reduced.

Drawings

Further advantages, features and details of the invention are given by the following description of preferred embodiments and with the aid of the drawings. The features and feature combinations mentioned in the description above and those mentioned in the description of the figures and/or shown in the figures individually can be used not only in the respectively specified combination but also in further combinations or alone without leaving the scope of the invention. Identical or functionally identical elements are assigned the same reference numerals. For reasons of clarity, it is possible that an element is not provided with its reference numeral in all the figures, but its corresponding assignment is not lost. Wherein:

figure 1 shows in an exploded perspective view a stator of a camshaft adjuster of a camshaft unit and a sealing element before its assembly according to the prior art,

figure 2 shows the stator of the camshaft adjuster of the camshaft unit according to the invention in a plan view,

figure 3 shows the stator according to figure 2 in a longitudinal section,

figure 4 shows a part IV of the stator according to figure 2 in a top view,

figure 5 shows a part IV of the stator according to figure 2 in a longitudinal section V-V,

figure 6 shows in longitudinal section a part of a camshaft unit according to the invention in the region of the receiving element,

fig. 7 shows, in principle, a sealing site according to fig. 6, with the sealing element in the hardened state,

fig. 8 shows, in principle, a sealing site according to fig. 6, with the sealing element in a compressed state,

fig. 9 shows a camshaft adjuster of a camshaft unit according to the prior art in an exploded perspective view.

Detailed Description

The camshaft unit 10 constructed according to the prior art is constructed in the form of a camshaft adjuster, the stator 14 of which is constructed according to fig. 1. The camshaft adjuster 10 can cause the opening and closing times of gas exchange valves of an internal combustion engine to be changed during operation of the internal combustion engine, which is not shown in detail.

Fig. 9 shows a further camshaft adjuster 10 according to the prior art in an exploded view. A general structure of the camshaft adjuster 1 is thus to be seen by way of example, wherein the invention is not limited to this structure.

For this purpose, the relative angular position of a camshaft, not shown in detail, of the internal combustion engine relative to a crankshaft, not shown in detail, of the internal combustion engine is varied steplessly by means of the camshaft adjuster 10, wherein the camshaft is twisted relative to the crankshaft. The opening and closing times of the gas exchange valves are shifted by the rotation of the camshaft, so that the internal combustion engine can generate its optimum power at the respective speed.

The cylindrically formed stator 14 is connected in a rotationally fixed manner to a drive wheel 11, which is shown in fig. 9 by way of example, of a crankshaft, not shown in detail, of the internal combustion engine. The drive wheel is constructed in the form of a chain wheel, through which a chain, not shown in detail, is guided as a drive element. The drive wheel can, however, also be a toothed pulley, through which the drive belt is guided as a drive element. Via this drive element and the drive wheel 11, the stator 14 is in driving connection with the crankshaft.

The stator 14 has a cylindrical stator base body 16, on the inside 18 of which radially inwardly extending webs 20 are formed at uniform distances, so that a gap 22 is formed between each two adjacent webs 20. A pressure medium (usually hydraulic fluid) is introduced into the space 22 in a controlled manner by means of a hydraulic valve, which is not shown in detail. The stator 14 is designed as a rotor 12, which is shown in fig. 9 and comprises the camshaft adjuster 10.

In principle, the stator base body 16 can also be designed in one piece with a drive wheel designed as a sprocket wheel within the scope of the invention and sealed at its ends by means of stator covers 19, 21 designed substantially in the form of a disk. Alternatively, the stator cover 21, which also serves as a locking disk, can be provided integrally with the drive wheel 11, as is shown by way of example in fig. 9. The stator covers 19, 21 are screwed in a sealed manner to a stator base body 16 by means of bolts 23, which has openings 38 in the webs 20, through which the bolts 23 pass.

The bolts 23 are fixed with a specific prestress, so that the stator covers 19, 21 and the stator base body 16 form a friction partner, between which a static friction occurs by screwing.

The blades 13 of the rotor 12 are positioned to project into the space 22, the blades being arranged on the rotor hub 15 of the rotor 12. The rotor hub 15 has a number of blades 13, depending on the number of spaces 22. The rotor 12 has a not shown rotational axis about which it is configured to be rotatable, wherein the rotational axis and the longitudinal axis 24 of the stator 14 are configured coaxially.

Thus, the gap 22 is divided into a first pressure chamber and a second pressure chamber by the vanes 13, respectively. In order to reduce the pressure losses in the first and second pressure chambers, the webs 20 are designed with their web end sides 26 in a sealing manner against the outer surface of the rotor hub 15. The end side 17 of the vane 13 likewise bears in a sealing manner against an inner wall 28 of the inner side 18, which is located opposite the outer surface.

The rotor 12 is connected in a rotationally fixed manner to a camshaft of the internal combustion engine. In order to change the angular position between the camshaft and the crankshaft, the rotor 12 is rotated relative to the stator 14 about its axis of rotation, which is configured coaxially with the longitudinal axis 24. For this purpose, depending on the selected direction of rotation, the pressure medium in the first pressure chamber or the second pressure chamber is put under pressure, while the second pressure chamber or the first pressure chamber is relieved of load. The unloading takes place in a tank inlet not shown in detail.

Hydraulic valves, which are not shown in detail, are provided for the hydraulic supply of the camshaft adjuster 10. Such hydraulic valves are known and may be constructed in different forms.

Due to the pressure chamber of the design through which hydraulic fluid can flow, it is necessary to provide the camshaft adjuster 10 with a sealing element 30, which ensures a secure sealing of the pressure chamber.

As shown in fig. 1, the sealing element constructed according to the prior art is embodied as a profiled sealing element 30'. The stator 14 has receiving elements 36 on its front side 32 and its rear side 34, which is formed opposite the front side 32, which are formed in a closed and undulating manner on the circumference of the stator 14. The receiving element 36 is preferably embodied in the form of a groove in a sealing surface 40 of the front side 32 or the rear side 34. In the assembled state of the camshaft adjuster 10, a second sealing surface, not shown in detail, is arranged opposite the first sealing surface 40, wherein the sealing element 30' is arranged between the two sealing surfaces.

Prior to assembly, the sealing element 30' is configured circularly, as shown in fig. 1. The sealing element 30' is inserted into the groove 36 by means of a tool (usually a so-called slide) and held stationary. Subsequently, further camshaft adjuster components, which are not shown in detail here, such as the stator covers 19, 21 shown in fig. 9, are arranged on the end side 32 or the rear side 34, respectively, and are fastened by means of connecting elements, which are not shown in detail, which are accommodated in openings 38 of the stator 14, so that a sealing element 30' is arranged in a sealing manner between the stator 14 and the further camshaft adjuster components. This can lead to non-tightness of the camshaft adjuster 10, since the sealing element 30' has a tendency to return to its original circular shape after being inserted into the groove 36 and/or can tilt because it is not fixed in the groove 36.

The camshaft unit 10, which is embodied in the form of a camshaft adjuster in the exemplary embodiment according to the invention, has a stator 14 which is constructed according to fig. 2 to 8. The stator 14 has receiving elements 36 in the form of slots on the front side 32 and the rear side 34. The groove 36 is designed to accommodate the sealing element 30, wherein the sealing element 30 is constructed from a material which changes its flow behavior up to the final hardening state. In other words, the sealing element 30 can be applied to at least one of the sealing surfaces, the first sealing surface 40 and/or the second sealing surface, in the liquid state and its final shape can only be obtained by assembling the two components (in this embodiment the stator 14 and the further camshaft adjuster component, i.e. the cover or the locking disk). The sealing element 30 is constructed in the form of a force-dividing seal (kraft negenschlussdiching).

The groove 36 is of undulating design in its circumferential course, wherein the groove portion includes an opening 38 bounded in the direction of the inner wall 28. Fluid in the form of hydraulic liquid present in this embodiment is therefore inhibited from flowing out through the opening 38. The stator 14 has slots 36 on its front side 32 and on its rear side 34, so that the stator is constructed hermetically on both sides. The end side 32 or the rear side 34 respectively corresponds to a first sealing surface 40, which is arranged opposite a second sealing surface, not shown in detail, of the further camshaft adjuster component, wherein the sealing surfaces are sealed by the sealing element 30 on both sides of the sealing element 30 in the radial and axial directions.

In fig. 4 to 6, the groove 36 is shown in a detail view. In particular, the illustration according to fig. 5 indicates a relatively small dimension of the groove 36 in comparison with the opening 38. The groove 36 has a constant first width B1 on the first sealing surface 40, wherein the groove bottom 42 has a second width B2 that is less than the first width B1. The groove base 42 is bounded on both sides by groove walls 44, wherein a transition 46 formed between the groove walls 44 and the groove base 42 is rounded off. The groove wall 44 is embodied at an angle to an imaginary plane 48 that is orthogonal to the first sealing surface 40, wherein an angle α is formed between the imaginary plane 48 and the groove wall 44, wherein the angle α has a value of approximately 2 ° -8 °, preferably 5 °.

The introduction of the sealing element 30 is facilitated by the slightly inclined groove wall 44, which is introduced in the form of a strip into the groove 36 in the liquid state. In this liquid state, the material of the sealing element 30 has flow properties, which correspond to a flowable state, wherein the material has surface stresses so that the strip retains its shape until further processing. The material is based on a polyacrylate construction. A further treatment is electromagnetic radiation, in particular using ultraviolet light, and leads to a hardening of the sealing element 30.

The groove 36 has a depth T in addition to the widths B1, B2, wherein in particular the width B1 is greater than the depth T. The sealing element 30 is injected in the form of a strip into the groove 36, in other words positioned on the groove bottom 42, by means of a spraying tool, not shown in detail. The injection tool has a filling nozzle with a corresponding diameter in order to obtain a specific thickness D of the strip, wherein the diameter should be at least slightly smaller than at least the first width B1. For better positioning of the strip in the groove 36, it is advantageous to keep the depth T as small as possible, but in particular the width B1 is implemented correspondingly large in the hardened state and during operation for the expansion of the sealing element 30.

The stator 14 and the further camshaft adjuster components are assembled after the sealing element 30 has completely hardened. In fig. 7 and 8, the sealing element 30 is shown in a compressed state in a hardened state or in another state after assembly. In other words, the sealing element 30 has an elastic deformation, wherein the sealing action is obtained by a deformation based on compression. In other words, the sealing element 30 is configured in the form of a compression sealing element.

During operation of the camshaft unit 10, i.e., in this exemplary embodiment, in particular during operation of the camshaft adjuster 10, additional loads (thermal loads) occur, wherein the sealing element 30 can expand further and can bear and/or bear against the groove wall 44. In other words, the sealing element 30 is at least designed to bear against the first sealing surface 40 during operation, since the groove 36 is located in the first sealing surface 40. In order to improve the sealing by means of the sealing element 30, this sealing element is also designed to bear against the second sealing surface during operation.

The sealing element 30 is applied in the liquid state to a first sealing surface 40 of the end face 32 and to a second sealing surface, which is opposite the first sealing surface 40 and belongs to a further camshaft adjuster component.

The method according to the invention for producing a camshaft unit 10 is characterized in that the seal between the two sealing surfaces 40 is formed by means of a sealing element 30, wherein the sealing element 30 assumes its final shape during the assembly of the two components.

In a first step, the sealing element 30 is applied to at least one of the sealing surfaces 40 in a liquid state. In a second step, the curing is carried out by means of electromagnetic radiation, wherein the radiation is carried out by means of an ultraviolet radiation beam. Finally, in a third step, the sealing element 30 is compressed, wherein the two components are at least placed opposite one another in this embodiment of the stator 14 and the further camshaft adjuster component, for example a cover, wherein the hardened sealing element 30 is pressed together.

If, for example, the sealing element 30 is applied to only one of the sealing surfaces, for example the first sealing surface 40, and thus only to the stator 14, the sealing element 30 extending beyond the sealing surface 40 in the radial direction is compressed by placing two components against one another and closing the gap between the components formed on the basis of the sealing element 30. If two components have a sealing element 30, i.e. in other words each component has a sealing element 30, two oppositely configured sealing elements 30 are in contact with each other and are compressed by closing a gap between the two components which is configured on the basis of the seal 30 extending in the radial direction.

The seal between the two components according to the invention is not limited to the camshaft adjuster described and shown. The application possibilities are likewise provided in further components of the camshaft unit, such as actuators and hydraulic valves. The sealing according to the invention between the components, for example between the camshaft adjuster and the actuator, is likewise conceivable.