JP3932613B2 - Timing chain mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a timing chain mechanism for transmitting the power of a crankshaft of an internal combustion engine from a crank sprocket to a cam sprocket.
[0002]
[Prior art]
An example of a conventional timing chain mechanism is disclosed in Japanese Utility Model Laid-Open No. 2-145342. In this system, a chain damper having a chain guide function is provided on the tension side of the timing chain stretched between the crank sprocket and the cam sprocket, and one end is swingably fixed on the slack side and the other end is secured. A chain slipper which is free and has a chain guide and a tension urging function is provided, and power is transmitted from the crank sprocket to the cam sprocket without the timing chain flapping.
[0003]
[Problems to be solved by the invention]
In the above-described conventional timing chain mechanism, the crank sprocket, cam sprocket, chain damper, and chain slipper are individually and sequentially assembled while matching the relative positional relationship when assembled to the internal combustion engine. For this reason, there is a problem that not only a long time is required for the assembly, but also the automation of the assembly is difficult.
[0004]
Therefore, an object of the present invention is to improve the assembling property to the internal combustion engine in the timing chain mechanism.
[0005]
[Means for Solving the Problems]
The technical means of the present invention taken in order to solve the above-mentioned problems are a timing chain stretched between a crank sprocket and a cam sprocket, and provided on the tension side of the timing chain to guide the timing chain. A chain damper and a chain slipper provided on the slack side of the timing chain, fixed at one end to an internal combustion engine so as to be swingable and free at the other end, and having a guide for the timing chain and a tension biasing function. In the timing chain mechanism, the chain damper is provided with a support portion capable of supporting the cam sprocket and a restriction portion capable of restricting the swing of the chain slipper to the slack side of the timing chain, and the chain damper is attached to the chain slipper. The crank sprocket is pivotally supported at one end and swingable. A chain stopper guide having a support portion capable of supporting a rack is provided at one end of the chain slipper so as to be swingable, and the chain damper and the chain stopper guide are opposed to each other between the chain stopper guide and the chain damper. The cam sprocket and the crank sprocket are supported by the support part and the support part, respectively, and the swinging of the chain slipper is restricted by the restriction part, Before the crank sprocket, the cam sprocket and the chain slipper are attached to the internal combustion engine, a temporary assembly is formed together with the chain damper and the chain stopper guide.
[0006]
According to the above means, the timing chain, the crank sprocket, the cam sprocket, the chain damper, the chain slipper, etc. are temporarily placed in a relative positional relationship in the state where they are assembled to the internal combustion engine before the assembly to the internal combustion engine. Since it is an assembly, it is not necessary to sequentially assemble each member to the internal combustion engine while matching the relative positional relationship with other members, and it is only necessary to assemble each member sequentially. For this reason, the assembling property is remarkably improved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a timing chain mechanism according to the present invention will be described with reference to the drawings.
[0008]
FIG. 1 shows a state before being assembled to an internal combustion engine, and is in a temporary assembly state as will be described below. In FIG. 1, a timing chain 11 is stretched between cam sprockets 10 a and 10 b and a crank sprocket 12. The crank sprocket 12 is rotated clockwise in FIG. 1 by being assembled to the crankshaft of the internal combustion engine. Between the cam sprocket 10 b and the crank sprocket 12, which are the tension side of the timing chain 11, a chain damper 13 having a guide portion 13 a that guides the tension side of the timing chain 11 is disposed and is the slack side of the timing chain 11. The cam sprocket 10a and the crank sprocket 12 have a swing fulcrum 15 at one end, and can be swung by fixing the swing fulcrum to the internal combustion engine. A chain slipper 14 that guides the slack side timing chain 11 and has a tension urging function is provided.
[0009]
The chain damper 13 is pivotally supported by the swing fulcrum 15 of the chain slipper 14 so as to be swingable. The chain damper 13 includes a support portion 13d that can support the cam sprockets 10a and 10b when the chain damper 13 swings counterclockwise around the swing fulcrum portion 15, and the timing chain 11 of the chain slipper 14. A restricting portion 13b that can restrict the swing toward the slack side (counterclockwise in FIG. 1) is provided.
[0010]
Further, a chain stopper guide 16 is pivotally supported on the swing fulcrum 15 of the chain slipper 14 so as to be swingable. The chain stopper guide 16 is provided with a support portion 16c capable of supporting the crank sprocket 12 by swinging clockwise around the swing fulcrum portion 15, and is also provided with a locking portion 16a. As shown in FIG. 3, the other end of the spring 17 whose one end is locked to the locking portion 13 c formed on the chain damper 13 is locked to the locking portion 16 a, and the chain is held by this spring 17. The stopper guide 16 is biased clockwise around the swing fulcrum 15 and the chain damper 13 is biased counterclockwise around the swing fulcrum 15.
[0011]
As a result, the cam sprockets 10 a and 10 b are supported (pressed) by the support portion 13 d of the chain damper 13, and the crank sprocket 12 is supported (pressed) by the support portion 16 c of the chain stopper guide 16. Is stretched. For this reason, the chain slipper 14 is swung counterclockwise around the swing fulcrum 15 by the timing chain 11 and is held in contact with the restricting portion 13b. As a result, the cam sprockets 10a and 10b, the timing chain 11, the crank sprocket 12, the chain damper 13, the chain slipper 14 and the like are in a relative position in a state where they are assembled to the internal combustion engine before being assembled to the internal combustion engine. It is a temporary assembly with no relationship and no separation.
[0012]
Next, the assembly of the timing chain mechanism as the temporary assembly to the internal combustion engine will be described.
[0013]
The temporary assembly is assembled from above the internal combustion engine with the cam sprockets 10a, 10b held by the assembly jig 18. At this time, as shown in FIG. 2, the arm portion 16 b provided on the chain stopper guide 16 comes into contact with the stopper portion 19 formed in the internal combustion engine, and the chain stopper guide 16 is resisted against the urging force of the spring 17. Swing counterclockwise. As a result, the support portion 16c of the chain stopper guide 16 is separated from the crank sprocket 12, the crank sprocket 12 becomes free, and the crank sprocket 12 becomes the crankshaft when the axis of the crank sprocket 12 coincides with the axis of the crankshaft (not shown). It is assembled. Thereafter, the cam sprockets 10a and 10b are lowered by the assembling jig 18, and the cam sprockets 10a and 10b are assembled to the camshaft where the shaft centers of the cam sprockets 10a and 10b coincide with the respective shaft centers of the camshaft (not shown). The assembly jig 18 is removed. Thereafter, the chain damper 13, the chain slipper 14, and the chain stopper guide 16 are further lowered, the swing fulcrum 15 of the chain slipper 14 is fixed to a predetermined fixing portion of the internal combustion engine, and the chain damper 13 is connected to the chain damper 13. A damper fixing portion 20 that restricts clockwise swing is assembled.
[0014]
FIG. 2 shows a state in which the chain stopper guide 16 is assembled to the internal combustion engine as described above, and the chain stopper guide 16 is pushed up by the arm portion 16b by the stopper portion 19, and a predetermined gap is formed between the guide portion 16c and the crank sprocket 12. At the same time, the chain damper 13 is fixed by the swing fulcrum 15 and the damper fixing part 20, and a predetermined gap is also formed between the guide part 13d and the cam sprockets 10a, 10b. The chain slipper 14 is supported by the chain tensioner 21 so as to be separated from the restricting portion 13b and hold a predetermined tension in the timing chain 11.
[0015]
As described above, in the present embodiment, the cam sprockets 10a and 10b, the timing chain 11, the crank sprocket 12, the chain damper 13, the chain slipper 14, and the like are attached to the internal combustion engine before being assembled to the internal combustion engine. Since it is a temporary assembly with no relative separation in the relative positional relationship in the assembled state, it is necessary to sequentially assemble each member to the internal combustion engine while matching the relative positional relationship with other members. As a result, the assembling property is remarkably improved, and automatic assembling can be easily performed.
[0016]
【The invention's effect】
As described above, according to the present invention, the timing chain, the crank sprocket, the cam sprocket, the chain damper, the chain slipper, and the like are relative to each other in the state where they are assembled to the internal combustion engine before the assembly to the internal combustion engine. Since it is a temporary assembly with a relationship, it is not necessary to sequentially assemble each member to the internal combustion engine while matching the relative positional relationship with other members, it is only necessary to assemble each member sequentially, and the assembling property is improved. In addition to being significantly improved, automatic assembly can be easily performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a temporary assembly state in an embodiment of a timing chain mechanism according to the present invention.
FIG. 2 is a configuration diagram showing an assembly state to an internal combustion engine in an embodiment of a timing chain mechanism according to the present invention.
3 is a side view showing a tensioned portion of a spring in the embodiment shown in FIGS. 1 and 2. FIG.
[Explanation of symbols]
10a, 10b Cam sprocket 11 Timing chain 12 Crank sprocket 13 Chain damper 13b Restricting portion 13d Bearing portion 14 Chain slipper 15 Swing fulcrum portion 16 Chain stopper guide 17 Spring

Claims (1)

A timing chain stretched between the crank sprocket and the cam sprocket, a chain damper provided on the tension side of the timing chain for guiding the timing chain, and provided on the slack side of the timing chain, with one end swinging. A timing chain mechanism, which is fixed to an internal combustion engine so as to be movable and free at the other end, and includes a chain slipper having a guide for the timing chain and a tension biasing function, and a bearing capable of supporting the cam sprocket on the chain damper. And a restriction part capable of restricting the swing of the chain slipper to the slack side of the timing chain, and pivotally supporting the chain damper at one end of the chain slipper and supporting the crank sprocket Chain stopper guy with special support Is provided at one end of the chain slipper so as to be swingable, and a spring for swinging the chain damper and the chain stopper guide in opposite directions is stretched between the chain stopper guide and the chain damper. The cam sprocket and the crank sprocket are supported by the support part and the support part, respectively, and the swing of the chain slipper is restricted by the restriction part, and the crank sprocket, the cam sprocket and the chain slipper are internally A timing chain mechanism comprising a temporary assembly together with the chain damper and the chain stopper guide before being attached to an engine.

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