CN-115176072-B - Method for assembling a camshaft drive

Abstract

A method for assembling a camshaft drive of an internal combustion engine is disclosed, having the steps of i. providing a camshaft drive preassembled on a base plate with a transmission system which is in form-fitting abutment against a first camshaft drive wheel, a second camshaft drive wheel and a crankshaft wheel, and having a tensioning device which can be brought from an assembled position into a tensioning position in which the tensioning device does not load the transmission system, in which tensioning position the tensioning device holds the transmission system under tension, ii. locking the second camshaft drive wheel and the crankshaft wheel in a torque-proof manner, iii. rotating the first camshaft drive wheel in a first rotational direction, in which rotation a section of the transmission system between the first camshaft drive wheel and the second camshaft drive wheel is made loose and the transmission system is made to be in contact with the tensioning device, iv. releasing the tensioning device arranged between the crankshaft wheel and the first camshaft drive wheel, acting on the transmission system, v. rotating the first camshaft drive wheel in a second rotational direction opposite to the first rotational direction, whereby the tensioning device locks the second camshaft drive wheel and the first camshaft drive wheel and the crankshaft drive.

Inventors

• M. Hellmeier

Assignees

• 标致雪铁龙汽车股份有限公司

Dates

Publication Date

20260505

Application Date

20210225

Priority Date

20200226

Claims (4)

1. 1. A method for assembling a camshaft drive (40) of an internal combustion engine, having the steps of: Providing a camshaft drive (40) preassembled on a base plate (45) with a transmission system (41) which bears positively against a first camshaft drive wheel (10), a second camshaft drive wheel (20) and a crankshaft wheel (30), the base plate (45) further having a tensioning device (43) which can be brought from an assembly position (46) in which it does not load the transmission system (41) into a tensioning position (47) in which it holds the transmission system (41) under tension, Rotationally locked the second camshaft drive wheel (10) and the crankshaft wheel (30), Rotating the first camshaft drive wheel (10) in a first rotational direction (51), in which rotation a section (42) of the transmission system (41) between the first camshaft drive wheel (10) and the second camshaft drive wheel (20) is relaxed and the remaining sections between the Qu Zhoulun (30) and the first camshaft drive wheel (10) and between the crankshaft wheel (30) and the second camshaft drive wheel (20) are tensioned and the transmission system (41) is brought into contact with a tensioning device (43), Releasing a tensioning device (43) which is arranged between the crankshaft wheel (30) and the first camshaft drive wheel (10) and acts on the transmission system (41), Rotating the first camshaft drive wheel (10) in a second rotational direction (52) opposite to the first rotational direction (51) so that the tensioning device (43) tensions the transmission system (41), and Fixing the first camshaft drive wheel (10) to the first camshaft (11), fixing the second camshaft drive wheel (20) to the second camshaft (21), and fixing the crankshaft wheel (30) to the crankshaft (31).
2. 2. Method according to claim 1, wherein the unlocking device (49) holding the tensioning device (43) is released only by applying a force (F) opposite to the subsequent direction of action (48), wherein the torque (M51) rotating the first camshaft wheel (10) in the first direction of rotation (51) is selected so much that the tensioning device (43) is accordingly applied with the force (F) by tightening the transmission (41) in order to release the tensioning device (43), wherein the tensioning device (43) acts on the transmission (41) in the released state in the direction of action (48) opposite to the force (F) and thereby tensions the transmission.
3. 3. -A base plate (45) with a preassembled camshaft drive (40) using the method according to claim 1 or 2 and a transmission (41) which rests in a form-fitting manner against a first camshaft drive wheel (10), a second camshaft drive wheel (20) and a crankshaft wheel (30), the base plate (45) further having a tensioning device (43) which can be brought from an assembled position (46) in which it does not load the transmission (41) into a tensioning position (47) in which it holds the transmission (41) under tensioning force, wherein the tensioning device (43) can be released only by applying a force (F) opposite to the subsequent direction of action (48), wherein a torque (M51) can be applied to the first camshaft drive wheel (10) which force (F) is applied by tightening the transmission (41) in order to unlock the tensioning device (43) held in the co-ordinated state (49).
4. 4. Use of a base plate (45) with a preassembled camshaft drive (40) using a method according to claim 1 or 2 on an internal combustion engine (60) having an assembly position (61) in which the base plate (45) can be placed only when a tensioning device (43) arranged on the base plate (45) is pivoted into an assembly position (46) and locked in the assembly position, V. wherein the tensioning device (43) does not exert a tensioning force on the drive train (41) in the assembly position (46), wherein, In order to change the tensioning device (43) from the assembly position (46) into a ready-to-run position (47), in which an unlocking device (49) holding the tensioning device (43) is unlocked and in which the tensioning device (43) is pressed in an action direction (48) onto the drive train (41) and thereby tensions the drive train, Applying a force (F) opposite to the subsequent direction of action (48), Wherein, due to the lack of accessibility of the tensioning device (43) in the assembly position (61), the force (F) can also be exerted by a tensile stress in the drive train (41), which is caused by torsion of the camshaft drive wheel (10) relative to the crankshaft wheel (30).

Description

Method for assembling a camshaft drive Technical Field The present disclosure relates to a method for assembling a camshaft drive, in particular a chain camshaft drive, having a drive train. The drive train may in principle be a toothed belt or a camshaft, whereas the embodiments described later relate to a camshaft drive with a control chain. The disclosure relates in particular to a method for assembling a camshaft drive having an input camshaft and an output camshaft. In the camshaft drive, the control chain extends V-shaped from one crankshaft wheel to two camshaft drives. Background German publication DE 36,918 A1 relates to a chain tensioning device for an internal combustion engine. In the chain tensioning mechanism, a damping piston guided in a housing is axially loaded by a spring in the chain tensioning device. The damping piston can be locked by means of a fitting ring in the housing. In order to be able to bring the damping piston from the outside into the locked position by means of a tool and to be able to easily release the lock without the aid of a tool, the mounting ring engages in a groove of the damping piston provided with a bevel and a locking surface. The mounting ring is brought to the locking surface by means of a tool which can be inserted into the gap. The mounting ring engages with a groove of the housing and locks the movement of the damping piston. After assembly, the drive train is relaxed, the chain tensioning mechanism is not in contact with the tensioning rail, and the spring-loaded tensioner acting thereon is locked or locked. This may lead to a play between the crank wheel and the drive train, since the drive train sags downward and cannot engage the crank wheel in this case. The camshaft wheel cannot be fixed because the drive train can move relative to the crankshaft wheel. This can lead to control timing errors and in addition the crank wheel slips when screwed onto the crankshaft, which is often unnoticed during assembly and can lead to engine damage when the internal combustion engine begins to operate. Disclosure of Invention In one aspect of the disclosure, a method should be presented that enables assembly of a camshaft drive without a tool for unlocking the tensioner. The technical scheme of the invention solves the above-mentioned aspects. The technical solutions of the invention can be combined with each other in a technically meaningful way. The specification particularly characterizes and additionally details the disclosure in connection with the accompanying drawings. A method for assembling a camshaft drive of an internal combustion engine is therefore disclosed, having the following steps: i. A camshaft drive is provided, which is preassembled on a base plate and has a drive train which bears positively against a first camshaft drive wheel, a second camshaft drive wheel and a crankshaft wheel, and a tensioning device which can be brought into a tensioning position, in which the tensioning device does not act on the drive train, in which the tensioning device holds the drive train under tension, Rotationally locked the second camshaft drive wheel and the crankshaft wheel, Rotating the first camshaft drive wheel in a first rotational direction, in which rotation a section of the transmission system between the first camshaft drive wheel and the second camshaft drive wheel is relaxed and the transmission system is brought into contact with the tensioning device, Releasing a tensioning device which is arranged between the crankshaft wheel and the first camshaft drive wheel and acts on the transmission system, Rotating the first camshaft drive wheel in a second rotational direction opposite the first rotational direction, whereby the tensioner tightens the drive train, and Fixing the first camshaft drive wheel to the first camshaft, fixing the second camshaft drive wheel to the second camshaft, and fixing the crankshaft wheel to the crankshaft. A transmission system of this type, for example a toothed belt and a control chain, can be preassembled as a unit consisting of a camshaft drive wheel for the input camshaft and a camshaft drive wheel and a crankshaft wheel for the output camshaft. The unit consisting of a camshaft drive wheel for the inlet camshaft and a camshaft drive wheel and a crankshaft wheel for the outlet camshaft is preassembled on a base plate. The base plate facilitates the introduction of the unit into the corresponding position on the end side of the internal combustion engine. The base plate of the tensioning device configured in this way can be fitted into an internal combustion engine, wherein the tensioning device is no longer accessible at all after the base plate has been fitted into the internal combustion engine. The tensioning device is activated or released in that it is pressed in the opposite direction to the subsequent tensioning direction until the unlocking device is released from the latching hook or the like. The tensioning d