JP2015169329A - chain tensioner device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict occurrence of vibration at an endless chain wound around a driving sprocket and a driven sprocket even under an elongation of the endless chain or deterioration of a tensioner lifter, eliminate setting of excessive depressing force of the tensioner lifter, and reduce friction at a chain tensioner device in which one end part of a tensioner arm slidably contacted with an outer circumference of loosened side of the endless chain is rotatably supported by a device at a position adjacent to either the driving sprocket or the driven sprocket and a tensioner lifter for depressing the tensioner arm toward the endless chain is arranged at the device.SOLUTION: A roller 54 for holding an endless chain 30 between it and either a driving sprocket 28 or a driven sprocket 29 is rotatably supported at a supporting shaft 53 for rotatably supporting one end of a tensioner arm 40 to a device 11.

Description

  The present invention relates to a drive sprocket provided on a drive shaft that is rotatably supported by a housing, and a tensioner that is in sliding contact with the outer periphery of the endless chain that is wound around a driven sprocket that is provided on a driven shaft that is rotatably supported by the housing. A chain tensioner device in which one end of an arm is rotatably supported by the housing at a position close to the driving sprocket or the driven sprocket, and a tensioner lifter that presses the tensioner arm toward the endless chain is provided on the housing. About.

  A chain tensioner device that suppresses vibration of an endless chain by applying a predetermined pressure with a tensioner lifter to a tensioner arm that is in sliding contact with the outer periphery of the endless chain wound around the drive sprocket and the driven sprocket is, for example, a patent It is known from document 1.

JP 2008-115895 A

  However, in the one disclosed in the above-mentioned Patent Document 1, vibration is generated in the endless chain due to elongation of the endless chain or deterioration of the tensioner lifter. Therefore, in anticipation of elongation of the endless chain and deterioration of the tensioner lifter, It is necessary to set the pressing force, and in the initial state, the friction between the endless chain and the tensioner arm increases.

  The present invention has been made in view of such circumstances, and suppresses the occurrence of vibration in the endless chain due to elongation of the endless chain or deterioration of the tensioner lifter, and sets the pressing force of the tensioner lifter to be excessive. An object of the present invention is to provide a chain tensioner device that can reduce friction as unnecessary.

  To achieve the above object, the present invention provides a drive sprocket provided on a drive shaft that is rotatably supported by a housing, and an endless chain wound around a driven sprocket provided on a driven shaft that is rotatably supported by the housing. One end of a tensioner arm that is in sliding contact with the outer periphery of the loose side is rotatably supported by the housing at a position close to the drive sprocket or the driven sprocket, and a tensioner lifter that presses the tensioner arm toward the endless chain side In the chain tensioner device provided in the housing, a roller that sandwiches the endless chain between the driving sprocket and the driven sprocket can rotate on a support shaft that rotatably supports one end of the tensioner arm on the housing. It is the first feature that it is supported by.

  According to the present invention, in addition to the configuration of the first feature, the roller is located at a position where the endless chain is sandwiched between the driven sprocket and the driven sprocket at a meshing start portion where the endless chain starts meshing with the driven sprocket. A second feature is that the endless chain is disposed at a position where the endless chain is sandwiched between the drive sprocket and the engagement release portion where the endless chain is detached from the sprocket.

  In the present invention, in addition to the configuration of the second feature, the roller is disposed corresponding to the meshing start portion or the meshing release portion of the sprocket on the large diameter side of the driving sprocket and the driven sprocket. The third feature.

  According to the present invention, in addition to any of the configurations of the first to third features, the casing is an engine body of an internal combustion engine, and the drive shaft is rotatably supported by a crankcase of the engine body The driven shaft is a camshaft rotatably supported by a cylinder head of the engine body, and the roller is disposed in a chain passage formed in the engine body so as to run the endless chain. The fourth feature is that the cylinder head is rotatably supported via the support shaft.

  According to the present invention, in addition to the configuration of the fourth feature, an insertion hole that communicates with the chain passage is provided in a side wall of the cylinder head that forms a part of the outer wall of the chain passage, and the support shaft is provided with the insertion hole. A fifth feature is that the bolt is inserted into the cylinder head and screwed into the cylinder head.

  In the present invention, in addition to the configuration of the fifth feature, a support boss having an opening opened upward is provided integrally with the cylinder head so as to insert and support the tip of the bolt. An oil passage capable of guiding oil from the opening is formed on the central axis so that a part of the bolt is hollow, and the oil passage is provided between the inner peripheral surface of the roller and the outer peripheral surface of the bolt. A sixth feature is that an oil supply hole for guiding oil from the oil is provided.

  Furthermore, in addition to any of the configurations of the first to fourth features, the present invention includes a shaft portion rotatably supported by the housing, and the shaft portion having a center at an eccentric position. The support shaft having an eccentric shaft portion connected to the shaft portion is attached to the housing so that the rotation position of the shaft portion can be adjusted so that the roller is rotatably supported by the eccentric shaft portion. 7 features.

  According to the first aspect of the present invention, an endless chain is sandwiched between a roller that is rotatably supported by a support shaft that rotatably supports one end of a tensioner arm on a housing, and a driving sprocket or a driven sprocket. As a result, the endless chain vibration, which tends to occur at the part where engagement with the driven sprocket is started or the part where engagement with the drive sprocket is released, can be suppressed by the roller. It is not necessary to set the lifter pressing force excessively, and friction can be reduced.

  Further, according to the second feature of the present invention, the roller is arranged corresponding to the engagement start portion of the endless chain with respect to the driven sprocket or the engagement release portion where the endless chain is detached from the driving sprocket, so that the vibration is likely to occur. By suppressing the endless chain with a roller, vibration of the endless chain can be effectively suppressed.

  According to the third feature of the present invention, the vibration of the endless chain can be more effectively suppressed by suppressing the endless chain with the roller between the driving sprocket and the driven sprocket and the large-diameter side sprocket.

  According to the fourth feature of the present invention, it is possible to suppress the vibration of the endless chain in the timing transmission mechanism provided between the crankshaft and the camshaft of the internal combustion engine, thereby reducing friction and contributing to reduction in fuel consumption. it can.

  According to the fifth aspect of the present invention, the tensioner arm and the roller are supported by the bolt screwed into the cylinder head so as to be inserted into the insertion hole provided in the side wall of the cylinder head. The roller can be supported with a simple structure.

  According to the sixth aspect of the present invention, the splashed oil in the chain passage is guided from the support boss supporting the bolt to the oil passage in the bolt and further guided between the bolt and the roller. Can be used for lubrication.

  Further, according to the seventh feature of the present invention, the rotation position of the roller supported by the eccentric shaft portion of the support shaft is changed by adjusting the rotation position of the support shaft, and the roller acts on the endless chain. The pressing force to be adjusted can be adjusted.

It is a principal part longitudinal cross-sectional view of an engine main body, Comprising: It is sectional drawing which follows the 1-1 line | wire of FIG. FIG. 2 is a view taken along line 2-2 in FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is sectional drawing corresponding to FIG. 3 of 2nd Embodiment. FIG. 5 is a view taken in the direction of arrow 5 in FIG. 4.

  Embodiments of the present invention will be described with reference to the accompanying drawings.

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. First, in FIG. 1, the internal combustion engine is mounted on, for example, a motorcycle. 12, a cylinder block 13 that is inclined forward and coupled to the crankcase 12, a cylinder head 14 that is coupled to the cylinder block 13, and a head cover 15 that is coupled to the cylinder head 14, A crankshaft 16 having an axis along the width direction of the motorcycle is rotatably supported by the crankcase 12.

  Referring also to FIG. 2, the cylinder head 14 is provided with an intake valve 17 that can be opened and closed and an exhaust valve 18 that can be opened and closed. The intake and exhaust valves 18 are driven to open and close. The valve mechanism 19 that rotates has a shaft line parallel to the crankshaft 16 and is rotatably supported by the cylinder head 14. The valve mechanism 19 swings according to the rotation of the camshaft 20 and swings the intake air. An intake rocker arm 21 that opens and closes the valve 17 and an exhaust rocker arm 22 that swings according to the rotation of the camshaft 20 and opens and closes the exhaust valve 18 are provided.

  The camshaft 20 has a pair of caps 25 fastened to the cylinder head 14 by a pair of bolts 24, 24 at two locations spaced in the direction along the axis of the camshaft 20 with the cylinder head 14. Rotational power is transmitted from the crankshaft 16 through a timing transmission mechanism 27 to one end of the camshaft 20 protruding from one cap 26.

  In the timing transmission mechanism 27, an endless chain 30 is wound around a driving sprocket 28 provided on the crankshaft 16 serving as a driving shaft and a driven sprocket 29 provided on one end of the camshaft 20 serving as a driven shaft. A chain passage 31 for running the endless chain 30 is formed in the crankcase 12, the cylinder block 13, and the cylinder head 14 of the engine body 11. In accordance with the rotation, the endless chain 30 travels in the travel direction indicated by the arrow 32.

  A chain guide 33 is brought into contact with an outer periphery of a tension side, which is a side pulled by the drive sprocket 28, of the endless chain 30 between the drive sprocket 28 and the driven sprocket 29. The chain guide 33 is formed of a synthetic resin having appropriate rigidity and elasticity so as to form a substantially arc shape along the endless chain 30 side, and the end of the chain guide 33 on the crankshaft 16 side opens upward. Are fitted into and supported by a support recess 34 provided in the crankcase 12. A support surface 35 facing the end opposite to the endless chain 30 is formed on the camshaft 20 side of the chain guide 33, and a contact support portion 36 that contacts the support surface 35 is provided in the cylinder head 14. . Further, on the both sides of the cam chain guide 33 near the support surface 35, projections 37 having a circular cross section are integrally projected, and the projections 37 are fitted on the coupling surface of the cylinder block 13 to the cylinder head 14. Thus, a positioning recess 38 for positioning is provided.

  A tensioner arm 40 having one end portion rotatably supported on the engine body 11 on an outer periphery of a loose side, which is a side fed from the drive sprocket 28, of an endless chain 30 between the drive sprocket 28 and the driven sprocket 29. The cylinder block 23 in the engine body 11 is provided with a tensioner lifter 41 that presses the tensioner arm 40 toward the endless chain 30 side.

  The tensioner lifter 41 is slidable on the support cylinder part 13a so as to come into contact with the tensioner arm 40 from the opposite side of the endless chain 30 and a support cylinder part 13a provided integrally with the cylinder block 13. A pressing body 42 to be fitted and a coil spring 43 that urges the pressing body 42 in a direction in which the tensioner arm is pressed against the endless chain 30 are provided.

  The support cylinder portion 13a has a sliding support hole 44 having one end opened on the chain passage 31 side, and is coaxially connected to the other end of the slide support hole 44 and opens to the outer end of the support cylinder portion 13a. A screw hole 45 is formed coaxially, and a lid member 46 is screwed into the screw hole 45.

  The pressing body 42 includes a cylindrical tube member 47 and a rubber contact member 48 attached to one end of the tube member 47. A spring accommodating hole 49 is formed in the cylindrical member 47 over the entire length, and the abutting member 48 is attached to one end of the cylindrical member 47 so as to close one end of the spring accommodating hole 49.

  The cylindrical member 47 is slidably fitted into the sliding support hole 44 so that the other end thereof faces the rubber receiving member 50 abutted against the inner end of the lid member 46. Between the receiving member 50 and one end of the cylindrical member 47, the coil spring 43, which is accommodated in the spring accommodating hole 49, is contracted. That is, the pressing body 42 is urged by the coil spring 43 in a direction in which the tensioner arm 40 is pressed against the endless chain 30 while the contact member 48 at the tip thereof is in contact with the tensioner arm 40. The support cylinder portion 13a is slidably fitted.

  Such a tensioner lifter 41 has a simple structure and does not deteriorate over time. Therefore, in order to prevent vibration of the endless chain 30, only the elongation of the endless chain 30 needs to be considered.

  One end portion of the tensioner arm 40 is close to a mesh start portion 51 where the endless chain 30 starts to mesh with the driven sprocket 29 or close to a mesh release portion 52 where the endless chain 30 is detached from the drive sprocket 28. In this embodiment, the meshing start portion of the driven sprocket 2 that is on the large-diameter side of the driving sprocket 28 and the driven sprocket 29 in this embodiment. At a position close to 51, the cylinder head 14 of the engine body 11 is rotatably supported via a bolt 53 which is a support shaft.

  Referring also to FIG. 3, a roller 54 that sandwiches the endless chain 30 between the bolt 53 and the driven sprocket 29 at the meshing start portion 51 is rotatably supported. The endless chain 30 is disposed in a chain passage 31 formed in the engine body 11 so as to run.

  The roller 54 is formed by adhering an elastic member 56 such as rubber to the outer periphery of a metal roller main body 55, and is formed on a bifurcated supported portion 40 a provided at one end of the tensioner arm 40. A part of the roller 54 is accommodated in the recess 57.

  An insertion hole 58 leading to the chain passage 31 is provided in the side wall 14 a of the cylinder head 14 forming a part of the outer wall of the chain passage 31, and the bolt 53 is inserted into the insertion hole 58. Screwed onto the cylinder head 14.

  The insertion hole 58 has a large-diameter hole portion 58a disposed on the opposite side of the chain passage 31 and a smaller diameter than the large-diameter hole portion 58a, and is formed between the large-diameter hole portion 58a and the chain passage 31. And is formed in a support protrusion 64 that protrudes integrally with the side wall 14 a of the cylinder head 14.

  On the other hand, the bolt 53 is fitted into a large-diameter head portion 53 a sandwiching a flat seal member 59 between the tip of the support protrusion 64 and a large-diameter hole portion 58 a of the insertion hole 53. A fitting shaft portion 53b coaxially connected to the diameter expansion protrusion 53a, and a screw shaft portion 53c coaxially connected to the fitting shaft portion 53b so as to be screwed to the screw hole portion 58b of the insertion hole 58; In addition, a support shaft portion 53d coaxially connected to the screw shaft portion 53c is integrally provided so as to support the supported portion 40a of the tensioner arm 40 and the roller 54.

  In a state where the bolt 53 is screwed into the cylinder head 14, the support shaft portion 53 d of the bolt 53 is arranged so as to cross the chain passage 31. A support boss 60 is provided integrally with the cylinder head 14 so as to insert and support the distal end portion of the support shaft portion 53d.

  The support boss 60 is formed so as to have an opening 61 that opens upward, and a part of the bolt 53, in this embodiment, the support shaft 53 d is oil from the opening 60. The oil passage 62 is formed so as to be hollow on the central axis, and the oil passage 62 is formed between the inner peripheral surface of the roller 54 and the outer peripheral surface of the support shaft portion 53 d of the bolt 53. An oil supply hole 63 for guiding oil from the support shaft portion 53d is provided in the support shaft portion 53d.

  Next, the operation of the first embodiment will be described. One end of the tensioner arm 40 slidably contacting the loose outer periphery of the endless chain 30 is rotated to the engine body 11 at a position close to the drive sprocket 28 or the driven sprocket 29. A roller 54 that is movably supported and sandwiches the endless chain 30 between the drive sprocket 28 or the driven sprocket 29 and supports one end of the tensioner arm 40 rotatably on the engine body 11. Since the endless chain 30 is sandwiched between the roller 54 and the drive sprocket 28 or the driven sprocket 29, the engagement with the driven sprocket 29 or the portion that starts the engagement with the driven sprocket 29 is achieved. Rolling vibration of endless chain 30 that is likely to occur at the part to be released Can be suppressed by 4, it can be made unnecessary to set excessively the pressure of the tensioner lifter 41 in anticipation of the growth of the endless chain 30, to reduce friction.

  Further, the roller 54 is located at a position where the endless chain 30 is sandwiched between the driven sprocket 29 at a meshing start portion 51 where the endless chain 30 starts to mesh with the driven sprocket 29 or from the driving sprocket 28. Since the endless chain 30 is sandwiched between the drive sprocket 28 by the disengagement release portion 52 to be detached, the endless chain 30 is suppressed by the roller 54 at a portion where vibration is likely to occur, and the endless chain 30 is vibrated. It can be effectively suppressed.

  Further, since the roller 54 is arranged corresponding to the sprocket on the large-diameter side of the drive sprocket 28 and the driven sprocket 29, in this embodiment, the meshing start portion 51 of the driven sprocket 29, the vibration of the endless chain 30 Can be suppressed more effectively.

  A drive sprocket 28 provided on the crankshaft 16 rotatably supported by the crankcase 12 of the engine body 11 and a driven sprocket 29 provided on the camshaft 20 rotatably supported by the cylinder head 14 of the engine body 11. An endless chain 30 is wound around the roller 54, and the roller 54 is disposed in a chain passage 31 formed in the engine body 11 so that the endless chain 30 travels, and the cylinder head 14 is connected to the cylinder head 14 via the bolt 53. Since it is rotatably supported, vibration of the endless chain 30 in the timing transmission mechanism 27 provided between the crankshaft 16 and the camshaft 20 of the internal combustion engine can be suppressed, and friction can be suppressed to reduce fuel consumption of the internal combustion engine. Can contribute.

  Further, an insertion hole 58 communicating with the chain passage 31 is provided in the side wall 14a of the cylinder head 14 forming a part of the outer wall of the chain passage 31, and the bolt 53 is inserted into the insertion hole 58 so as to form the cylinder head. 14, the tensioner arm 40 and the roller 54 can be supported with a simple structure.

  Further, a support boss 60 having an opening 61 opened upward is provided integrally with the cylinder head 14 so as to insert and support the tip of the bolt 53, and guides oil from the opening 61. The oil 53 from the oil passage 62 is formed between the inner peripheral surface of the roller 54 and the outer peripheral surface of the bolt 53, with the bolt 53 having a part formed hollow so that an oil passage 62 to be obtained is formed on the central axis. Since the oil supply hole 63 for guiding the oil is provided, the splashed oil in the chain passage 31 is guided from the support boss 60 that supports the bolt 53 to the oil passage 62 in the bolt 53 and further between the bolt 53 and the roller 54. Thus, lubrication between the bolt 53 and the roller 54 can be achieved.

  The second embodiment of the present invention will be described with reference to FIG. 4 and FIG. 5, but the parts corresponding to the first embodiment are only given the same reference numerals and shown in detail. The detailed explanation is omitted.

  The roller 54 is rotatably supported by a support shaft 65 that rotatably supports the supported portion 40 a at one end of the tensioner arm 40 on the cylinder head 14, and the support shaft 65 is supported by the cylinder head 14. A shaft portion 65a that is rotatably supported by the side wall 14a, and the shaft portion 65a is formed to have an eccentric shaft portion 65b having a center at an eccentric position and continuing to the shaft portion 65a. The roller 54 is rotatably supported by the eccentric shaft portion 65b.

  The side wall 14a of the cylinder head 14 is provided with a support hole 66 for fitting the shaft portion 65a in a rotatable manner, and the outer periphery of the shaft portion 65a is elastically formed on the inner periphery of the support hole 66. An annular seal member 67 that comes into contact is attached.

  One end of an arm 68 is fixed to the end of the shaft portion 65a outside the side wall 14a of the cylinder head 14, and the central axis of the support hole 66 is connected to the other end of the arm 68. A circular arc-shaped hole 69 having a center is formed. Bolts 70 inserted into the long holes 69 are screwed into the side walls 14a of the cylinder head 14, and the bolts 70 are in contact with both ends of the long holes 69 in the longitudinal direction when the bolts 70 are loosened. The arm 68 and the support shaft 65 can be rotated.

  According to the second embodiment, by adjusting the rotation position of the support shaft 65, the rotation center position of the roller 54 supported by the eccentric shaft portion 65b of the support shaft 65 is changed. The pressing force acting on the endless chain 30 (see the first embodiment) can be adjusted.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

DESCRIPTION OF SYMBOLS 11 ... Engine main body 12 which is a housing ... Crankcase 14 ... Cylinder head 14a ... Side wall 16 ... Crankshaft 20 which is a drive shaft ... Camshaft 28 which is a driven shaft ... Drive sprocket 29 ... driven sprocket 30 ... endless chain 31 ... chain passage 40 ... tensioner arm 41 ... tensioner lifter 51 ... meshing start part 52 ... meshing release part 53 ... Bolt 54 as a support shaft ... Roller 58 ... Insertion hole 60 ... Support boss 61 ... Opening 62 ... Oil passage 63 ... Oil supply hole 65 ... Support shaft 65a ...・ Shaft part 65b ... eccentric shaft part

Claims (7)

  A drive sprocket (28) provided on the drive shaft (16) rotatably supported by the housing (11) and a driven sprocket (29) provided on the driven shaft (20) rotatably supported by the housing (11). One end of a tensioner arm (40) that is in sliding contact with the outer periphery of the endless chain (30) that is wound around the end of the endless chain (30) closes to the housing (11) at a position close to the drive sprocket (28) or the driven sprocket (29). In the chain tensioner device that is rotatably supported and has a tensioner lifter (41) that presses the tensioner arm (40) toward the endless chain (30), the housing (11) is provided with the drive sprocket (28) or A roller (54) sandwiching the endless chain (30) between the driven sprocket (29) and the front sprocket (29) Chain tensioner apparatus characterized by being rotatably supported on a support shaft (53,65) for rotatably supporting one end portion to the skeleton (11) of the tensioner arm (40).   Position where the roller (54) sandwiches the endless chain (30) between the driven sprocket (29) and the driven sprocket (29) at a meshing start portion (51) where the endless chain (30) starts meshing Alternatively, the endless chain (30) is disposed at a position where the endless chain (30) is sandwiched between the driving sprocket (28) by a mesh release portion (52) where the endless chain (30) is detached from the driving sprocket (28). The chain tensioner device according to claim 1.   Of the drive sprocket (28) and the driven sprocket (29), the roller (54) is arranged corresponding to the engagement start portion (51) or the engagement release portion (52) of the sprocket (29) on the large diameter side. The chain tensioner device according to claim 2, wherein the chain tensioner device is provided.   The casing is an engine body (11) of an internal combustion engine, the drive shaft is a crankshaft (16) rotatably supported by a crankcase (12) of the engine body (11), and the driven shaft is the A camshaft (20) rotatably supported by a cylinder head (14) of the engine body (11), the roller (54) traveling the endless chain (30), and the engine body (11). 4. The structure according to claim 1, wherein the cylinder head is arranged in a chain passage formed so as to be rotatably supported by the cylinder head via the support shafts. The chain tensioner device according to claim 1.   An insertion hole (58) leading to the chain passage (31) is provided in a side wall (14a) of the cylinder head (14) forming a part of the outer wall of the chain passage (31), and the support shaft is inserted into the insertion passage. The chain tensioner device according to claim 4, wherein the chain tensioner device is a bolt (53) inserted into the hole (58) and screwed into the cylinder head (14).   A support boss (60) having an opening (61) opened upward is provided integrally with the cylinder head (14) so as to insert and support the tip of the bolt (53). An inner peripheral surface of the roller (54) and the bolt (53) partially hollowed so as to form an oil passage (62) capable of guiding oil from the portion (61) on the central axis The chain tensioner device according to claim 5, wherein an oil supply hole (63) for guiding oil from the oil passage (62) is provided between outer peripheral surfaces of the bolts (53).   A shaft portion (65a) rotatably supported by the housing (11), and an eccentric shaft portion (65b) having a center at an eccentric position and continuing to the shaft portion (65a). The support shaft (65) having the shaft portion (65a) can adjust the rotational position of the shaft portion (65a) while rotatably supporting the roller (54) by the eccentric shaft portion (65b). It is attached to (11), The chain tensioner apparatus of any one of Claims 1-4 characterized by the above-mentioned.

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