JP3786027B2 - Timing chain and chain transmission device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a timing chain used in an internal combustion engine or the like and meshed with a sprocket that requires synchronous rotation, and a chain transmission device using the timing chain.
[0002]
[Prior art]
Conventionally, a timing chain is provided with a predetermined timing mark for synchronously rotating a plurality of sprockets.
This timing mark is used when the timing chain and sprocket are meshed. By synchronizing the timing mark provided on the timing chain with the timing mark provided on the sprocket, multiple sprockets can rotate synchronously. Is secured.
[0003]
As a method of attaching the timing mark to the timing chain, plating treatment or baking coating is known (see Japanese Patent Application Laid-Open No. 10-10975). For example, as shown in FIG. The plate 102a is discriminated from other plates by performing plating or baking coating, and the identified plate 102a is attached in alignment with the timing marks 103a and 104a on the sprockets 103 and 104 side.
[0004]
[Problems to be solved by the invention]
However, in order to attach a timing mark by plating or baking as described above, a dedicated process (equipment) for performing plating or coating is required in addition to the manufacturing process of the plate itself. There is a problem that it costs a minute.
[0005]
In the internal combustion engine, but with reference to a timing chain to rotate synchronously with the crankshaft and the camshaft, should Ru match timing marks of the timing mark and sprocket side of the chain side, etc., assembly work It was annoying.
[0006]
In particular, when a silent chain is used as the timing chain, since the meshing margin of the chain and the sprocket is small, it is necessary to provide a mechanism for preventing the chain from coming off at the meshing portion (separation preventing mechanism). After the sprocket is attached, there is a problem that the assembly order is determined, for example, that the disengagement prevention mechanism must be attached, and the degree of freedom in assembly is limited.
[0007]
Such a problem is an obstacle when trying to improve the efficiency and automation of assembly work, such as assembling a certain number of parts in advance and modularizing it, so it is desirable to remove it beforehand. .
Accordingly, the present invention has been made in view of such a problem, and a timing chain capable of improving the degree of assembly freedom while suppressing an increase in cost associated with the attachment of a timing mark, and a chain transmission device using the timing chain The purpose is to provide.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a timing chain according to the present invention is a timing chain having guide plates on both sides in the chain width direction and meshing with a sprocket provided with a timing mark at a predetermined position. The timing plate is provided with a timing plate having a notch formed at the center portion on the side meshing with the sprocket at a position corresponding to the timing mark.
[0009]
With this configuration, the timing plate in which the notch is formed functions as a timing mark on the timing chain side, and plating or painting for attaching the timing mark is not necessary.
Further, in the invention according to claim 2, the timing chain connects in a longitudinal direction a link plate in which a meshing portion that meshes with the sprocket and a guide plate provided on both sides in the chain width direction with the link plate interposed therebetween. In the silent chain configured as described above, the notch portion of the timing plate is formed to have a size larger than the meshing portion of the link plate.
[0010]
With this configuration, the timing plate in which the notch is formed functions as a timing mark on the silent chain side, and when the silent chain is attached to the sprocket, the notch of the timing plate causes interference with the sprocket teeth. It can be avoided.
The invention according to claim 3 is characterized in that the link plate is used as a timing plate in which the cutout portion is formed.
[0011]
With this configuration, it is not necessary to newly prepare a timing plate in which a notch is formed, and it is only necessary to replace the guide plate at the corresponding position with a link plate.
The chain transmission device according to the present invention is attached to a shaft that requires synchronous rotation, a sprocket having a timing mark attached at a predetermined position, and a link plate formed with a meshing portion that meshes with the sprocket, It is constructed by connecting a guide plate provided on both sides in the chain width direction across the link plates, the longitudinal direction, and the a position to correspond to the timing mark of the sprocket out of the guide plates, or engagement portion of the link plate A silent chain provided with a timing plate having a notch portion and a position corresponding to a timing mark when the sprocket is mounted, and restricting movement of the silent chain in a direction away from the sprocket. And a guide portion for preventing tooth skipping It is obtained by the features.
[0012]
This configuration avoids interference between the guide plate of the silent chain and the sprocket teeth when the silent chain or sprocket is installed, and is on the opposite side of the side where the silent chain and the sprocket are engaged (the back side of the silent chain). ) Is provided with a guide portion.
Further, the invention according to claim 5 is characterized in that the silent chain includes timing plates formed with the notches on both sides in the chain width direction. With this configuration, interference with the sprocket teeth can be avoided on both sides of the silent chain in the width direction.
[0013]
Further, the invention according to claim 6 is characterized in that the silent chain includes a timing plate in which the notch is formed on only one side in the chain width direction. By comprising in this way, the other side guide plate has a function as a stopper (butting part) at the time of attachment.
The invention according to claim 7 is characterized in that the link plate is used as a timing plate in which the cutout portion is formed.
[0014]
【The invention's effect】
According to the timing chain according to the present invention, the timing plate in which the notch is formed has a function as a timing mark on the timing chain side. Therefore, the timing mark by plating or painting can be eliminated, and the number of processes (equipment) can be reduced. As a result, the cost can be reduced.
[0015]
According to the invention of claim 2, since the notch portion of the timing plate has a size larger than the meshing portion of the link plate, the timing mark by plating or painting can be abolished and the cost can be reduced. The interference between the guide plate of the silent chain and the sprocket teeth at the meshing portion can be avoided, and the assemblability can be improved.
[0016]
According to the invention of claim 3, the effect of the inventions of claims 1 and 2 can be obtained only by replacing the timing plate with a link plate, and the timing mark by plating or painting is eliminated. Cost reduction can be maximized.
According to the chain transmission device according to the present invention, the silent chain, the sprocket, and the guide portion can be independently attached without specifying the assembly order, so that the degree of assembly freedom is improved and the efficiency of the assembly can be improved. In addition, if the silent chain and the sprocket are attached with the guide portion attached in advance, the timing plate on which the notch portion is formed must be aligned with the sprocket teeth provided with the timing mark. Assembling cannot be performed, and there is an effect that erroneous assembly can be prevented.
[0017]
According to the invention of claim 5, since the silent chain includes the timing chain on both sides in the chain width direction, the assembly can be performed regardless of which of the silent chain and the sprocket is attached first, and the degree of freedom of the assembly is improved. To do. According to the invention which concerns on Claim 6, since the guide plate of the other side functions as a stopper, the drop-off at the time of the silent chain attachment and after attachment can be prevented. Further, modularization is facilitated, and assemblability and workability can be improved. That is, in the assembly by modularization, the silent chain, sprocket, guide part, etc. are assembled in advance in a jig and the like and modularized, and this is attached to the attachment part (main body). The timing plate formed with the notch part is attached to the chain. If only one of the width directions is used, for example, the guide part is attached to the jig, then the silent chain, and then the sprocket is attached to each component individually to form a module. Even in the case where the product is attached to the main body or the like upside down, the guide plate on the opposite side of the timing plate is caught by the teeth of the sprocket, and the silent chain can be prevented from falling off. Thereby, in the assembly by modularization, assembly workability can be improved without restricting the assembly direction.
[0018]
According to the invention concerning Claim 7, the effect of the invention concerning the said Claims 4-6 can be acquired only by changing the said timing plate to a link plate.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an overall schematic diagram in which a chain transmission device using a silent chain as a timing chain is applied to an internal combustion engine. As shown in the figure, the chain transmission device 1 includes a silent chain 2, sprockets 3 and 4, and a guide portion 5.
[0020]
As shown in FIG. 2, the silent chain 2 has a plurality of link plates 21 alternately connected in the longitudinal direction by connecting pins 22, and the both sides of the chain in the tooth width direction are also connected by connecting pins 22. A guide plate 23 is connected. The connecting pin 22 is fixed to the guide plate 23 by press fitting, caulking or the like.
[0021]
As shown in FIG. 3, the link plate 21 has a pair of holes 211 and 211 through which the connecting pin 22 is inserted, and the lower (sprocket side) center portion of the sprockets 3 and 4 in the figure. A meshing portion 212 that is notched so as to mesh with the teeth is formed.
Further, as shown in FIG. 4, the guide plate 23 is formed with a pair of holes 231 and 231 for fixing the connecting pin 22 by press-fitting, caulking or the like. The meshing part) is not formed. For this reason, the guide plate 23 has a function of restricting the movement (lateral shift) in the width direction of the silent chain 2 wound around the sprockets 3 and 4 and preventing the silent chain 2 from falling off the sprockets 3 and 4.
[0022]
Here, as a first feature of the present embodiment, the guide plate 23 is made to correspond to a position for positioning with each of the sprockets 3 and 4, that is, timing marks 31 and 41 on the sprocket 3 and 4 side described later. For the position, a plate 24 (hereinafter referred to as a timing plate) in which a notch 241 having a size equal to or larger than the meshing portion 212 of the link plate 21 is formed is used (see FIG. 1). ).
[0023]
As a result, the timing plate 24 has a function as a timing mark on the silent chain 2 side. In order to attach the timing mark, it is necessary to perform plating processing, baking coating, or the like on the predetermined guide plate 23. Absent.
Instead of using the timing plate 24, the guide plate 23 at the corresponding position may be replaced with the link plate 21. In this way, it is not necessary to newly add the timing plate 24, so that an increase in cost due to an increase in the number of parts can be prevented. However, in this case, since the connecting pin 22 is fixed to the insertion holes 211 and 211 of the link plate 21, the connecting pin 22 is formed in a stepped manner for press fitting and caulking (for press fitting). It is necessary to devise such as increasing the diameter).
[0024]
Further, the timing plate 24 may be applied to both sides in the chain width direction, or may be applied to only one side.
The sprockets 3 and 4 are respectively attached to the crankshaft 6 and the camshaft 7 of the engine, and timing marks 31 and 41 are respectively attached at predetermined positions. The timing marks 31 and 41 are aligned with the timing plate 24 and the silent chain 2 is wound around the sprockets 3 and 4 to set the initial positional relationship among the piston, the intake valve and the exhaust valve of the engine. It will be.
[0025]
The guide portion 5 is provided to prevent the silent chain 2 from coming off from the sprockets 3 and 4 (to prevent tooth skipping), and the silent chain 2 can be moved away from the sprockets 3 and 4. Regulate and secure the engagement.
The guide portion 5 is provided on the back side of the silent chain 2 (that is, on the opposite side to the side that meshes with the sprockets 3 and 4) in each meshing part of the silent chain 2 and the sprockets 3 and 4, and its width direction w is set to be smaller than one link width of the silent chain 2, and the clearance g with the silent chain 2 is set to a dimension such that the silent chain 2 does not come off the sprockets 3 and 4. The guide portion 5 may be formed integrally with a cylinder head, a chain case, or the like, or may be formed later as a separate member.
[0026]
The second feature of the present embodiment is that the setting position of the guide portion 5 and the positions of the timing marks 31 and 41 when the sprockets 3 and 4 are attached to the crankshaft 6 and the camshaft 7 respectively. It is configured to correspond (match) (see FIG. 1). With this configuration, the silent chain 2 and the sprockets 3 and 4 are engaged with each other at the position where the guide portion 5 is set.
[0027]
Next, an assembly process of the chain transmission device configured as described above will be described with reference to FIGS. 5 to 7 are equivalent views taken along the line AA of FIG.
5 and 6 show an example of an assembly process in the case where the guide portion is formed integrally with the cylinder head.
Conventionally, in such a case, it is necessary to wind the silent chain around the sprocket in advance and attach it to the crankshaft and camshaft (that is, it is necessary to attach the silent chain and the sprocket at the same time). It was annoying.
[0028]
This is because the clearance g is set to be small by the guide portion 5, so that if the guides 5 are installed separately, the guide plate 23 on the silent chain 2 side and the tooth tip 42 of the sprocket 4 interfere with each other as shown in FIG. 8. Because it ends up.
However, in the present embodiment, as described above, the setting position of the guide part corresponds to the position of the timing mark when the sprocket is attached, and the silent chain uses the timing plate, Silent chains and sprockets can be installed separately, avoiding interference during installation, improving assembly workability and freedom of assembly.
[0029]
In addition, under the configuration in which the guide portion is set in advance as described above, the silent chain and the sprocket are attached separately, and if the timing plate on the silent chain side and the timing mark on the sprocket side do not match, assembly is performed. This is not possible and can prevent erroneous assembly.
Hereinafter, each of the assembly steps shown in FIGS. In the following description, only the sprockets 4 and 4 attached to the camshaft 7 are targeted for convenience, but the same applies to the sprocket 3 attached to the crankshaft 6.
[0030]
FIG. 5 shows an assembly process when the silent chain 2 in which the timing plate 24 is applied to the cylinder head side in the chain width direction is used.
In FIG. 5, first, the sprockets 4 and 4 are respectively fixed to the intake side and exhaust side camshafts 7 and 7 of the engine by bolt fastening or the like (FIG. 5A). At this time, the timing marks 41, 41 on the sprocket 4, 4 side are at positions corresponding to the guide portion 5.
[0031]
Next, the silent chain 2 is attached so that the timing plate 24 is aligned with the timing marks 41 and 41 on the sprockets 4 and 4 side. As shown in FIG. Since interference with the teeth 42 of the sprocket 4 can be avoided, the siren and the chain 2 can be attached simply by moving them in the direction of the cylinder head 51 (that is, without exceeding the tooth tips of the sprocket 4). FIG.5 (b)-(d)).
[0032]
Then, the chain case 52 is attached to the cylinder head 51 together with the case cover 53 (FIG. 5E), and the assembly is completed (FIG. 5F).
Next, the assembly process of FIG. 6 will be described. FIG. 6 shows an assembly process when the silent chain 2 in which the timing plate 24 is applied to the case cover side in the chain width direction (that is, the opposite side of the cylinder head) is used.
[0033]
6, first, the silent chain 2 is arranged at a predetermined position (FIG. 6 (a). At this time, the timing plate 24 is in a position corresponding to the guide portion 5. Next, the sprockets 4 and 4 are moved to the positions thereof. The timing marks 41, 41 and the timing plate 24 are attached to the camshafts 7, 7 so that they are aligned with each other. However, as described with reference to FIG. Can be avoided by simply moving the sprockets 4 and 4 toward the cylinder head 51. After that, the sprockets 4 and 4 are fixed to the camshafts 7 and 7 (FIG. 6B). ) To (d)).
[0034]
Then, the chain case 52 is attached to the cylinder head 51 together with the case cover 53 (FIG. 6E), and the assembly is completed (FIG. 6F).
As described above, according to the silent chain and the chain transmission device according to the present embodiment, it is possible to improve the assembly workability and the degree of freedom of assembly while preventing erroneous assembly.
5 and 6, the silent chain 2 in which the timing plate 24 is applied only to one side in the chain width direction is used. However, the silent chain in which the timing plate 24 is applied to both sides in the chain width direction is used. If 2 is applied, assembling becomes possible even if any of the steps shown in FIGS. 5 and 6 is selected, and the degree of freedom in assembling work and assembling can be further improved.
[0035]
FIG. 7 shows an example of an assembling process when a chain case in which a silent chain, a sprocket and a guide portion are integrally formed is assembled in advance (modularized) and attached to a cylinder head. .
Conventionally, in such a case, in order to attach each component individually, it is necessary to attach a chain case with guide portions after attaching a silent chain and a sprocket (that is, the assembly order is fixed). )
[0036]
In addition, when a silent chain, sprocket and chain case are modularized in advance using a jig, etc., and this is assembled to the cylinder head, the outermost chain case after assembly is first held by the jig. However, in this case, as in the case of FIG. 5, the silent chain and the sprocket must be attached to the jig at the same time. It was.
[0037]
However, in the present embodiment, by adopting the configuration as described above, the chain case in which the guide portion is formed is first held (assembled) in the jig, and then the silent chain and the sprocket are each independently used as the jig. Since it can be held (assembled), it is easy to modularize and improve assembly efficiency.
Hereinafter, the assembly process of FIG. 7 will be described. In this assembling process, the silent chain 2 in which the timing plate 24 is applied only to the cylinder head 51 side is used (that is, the guide plate 23 is left on the case cover 53 side when the assembly is completed). ).
[0038]
First, the chain case 52 on which the guide portion 5 is formed is set on the jig 61, and then the silent chain 2 is set at a predetermined position in the chain case 52 (FIG. 7A). At this time, the timing plate 24 of the silent chain 2 is at a position corresponding to the guide portion 5.
Next, the sprockets 4 and 4 are set on the jig 61 so that the timing marks 41 and 41 are aligned with the timing plate 24 (FIGS. 7B and 7C). Since the silent chain 2 uses the timing plate 24 on the cylinder head 51 side (that is, the side opposite to the jig 61), the sprockets 4 and 4 need only be set from above. At this time, the guide plate 23 on the opposite side of the timing plate 24 has a function as a stopper, and the silent chain 2 can be prevented from going too far to the cylinder head 51 side.
[0039]
Next, the cylinder head 51 is turned upside down (FIG. 7D) with the silent chain 2, the sprockets 4, 4 and the chain case 52 set in the jig 61 (moduleized) upside down. The silent chain 2 has the timing plate 24 applied only to the cylinder head 51 side, so that the opposite side (case cover 53 side) as shown in FIG. ) Can interfere with the tooth tip 42 of the sprocket 4 and the silent chain 2 can be prevented from falling off the sprocket 4.
[0040]
Then, the jig 61 is removed (FIG. 7F), the sprockets 4 and 4 are fixed to the camshafts 7 and 7, and the case cover 53 is attached in place of the removed jig 61 (FIG. 7G). ), The assembly is finished (FIG. 7 (h)).
As described above, according to the silent chain and the chain transmission device according to the present embodiment, assembly by modularization is facilitated, and the efficiency of assembly work can be improved.
[0041]
In the above description, the one in which the timing plate 24 is applied to only one link of the silent chain 2 is used. However, as shown in FIG. 11, a plurality of links may be targeted.
In this way, the silent chain 2 can be more easily attached to the sprockets 3 and 4. That is, even if the timing plate 24 is applied, it is necessary that the guide plate 23 exceeds the tooth tips of the sprockets 3 and 4 in the adjacent portions. However, by applying the timing plate 24 to a plurality of links, This work can be made smaller. In this case, a plurality of timing marks 31 and 41 are also provided on the sprockets 3 and 4 side corresponding to the timing plate 24.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing a chain transmission device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of a silent chain.
FIG. 3 is a view showing a link plate of a silent chain that meshes with teeth of a sprocket.
FIG. 4 is a view showing a guide plate for preventing a lateral shift of the silent chain.
FIG. 5 is a view showing an example of an assembly process of the chain transmission device according to the present invention.
FIG. 6 is a view showing another example of the assembly process of the chain transmission device according to the present invention.
FIG. 7 is a view showing another example of the assembly process of the chain transmission device according to the present invention.
FIG. 8 is a view showing a relationship among a silent chain, sprocket teeth, and a guide portion during assembly of a conventional chain transmission device.
FIG. 9 is a diagram showing a relationship among a silent chain, sprocket teeth, and a guide portion when the chain transmission device according to the present embodiment is assembled.
FIG. 10 is a view showing the relationship among the silent chain, the sprocket teeth and the guide portion when the chain transmission device according to the present embodiment is assembled.
FIG. 11 is an overall configuration diagram showing a chain transmission device according to another embodiment of the present invention.
FIG. 12 is an overall configuration diagram showing a conventional chain transmission device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Chain transmission device 2 ... Silent chain 3, 4 ... Sprocket 5 ... Guide part 6 ... Crankshaft 7 ... Camshaft 21 ... Link plate 23 ... Guide plate 24 ... Timing plates 31, 41 ... Timing mark

Claims (7)

In the timing chain that has a guide plate on both sides in the chain width direction and meshes with a sprocket with a timing mark at a predetermined position,
A timing chain comprising a timing plate having a notch formed in a central portion on a side meshing with the sprocket at a position corresponding to the timing mark of the sprocket in the guide plate. The timing chain is a silent chain configured by connecting, in the longitudinal direction, a link plate that forms a meshing portion that meshes with the sprocket, and guide plates that are provided on both sides of the chain width direction across the link plate,
The timing chain according to claim 1, wherein the notch portion of the timing plate is formed to have a size larger than the meshing portion of the link plate. The timing chain according to claim 2, wherein the link plate is used as a timing plate in which the notch is formed. A sprocket mounted on a shaft that requires synchronous rotation and having a timing mark at a predetermined position;
A link plate formed with a meshing portion that meshes with the sprocket, and guide plates provided on both sides in the chain width direction across the link plate are connected in the longitudinal direction, and the timing of the sprocket among the guide plates A silent chain provided with a timing plate in which a cutout portion having a size larger than the meshing portion of the link plate is formed at a position corresponding to a mark;
A guide portion that is provided at a position corresponding to a timing mark when the sprocket is attached, and that prevents movement of the silent chain in a direction away from the sprocket to prevent tooth skipping;
A chain transmission device comprising: The chain transmission device according to claim 4, wherein the silent chain includes timing chains formed with the notches on both sides in the chain width direction. The silent chain, the chain transmission device according to claim 4, characterized in that it comprises only one side of the notch to form the timing chain and the chain width direction. The chain transmission device according to any one of claims 4 to 6, wherein the link plate is used as a timing plate in which the notch is formed.

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