Timing chain mechanism

Abstract

To provide a timing chain mechanism which can properly perform a lubrication.SOLUTION: A timing chain mechanism comprises a timing chain, a tensioner arm 70 and a hydraulic tensioner 80. The tensioner arm 70 includes a penetration hole 74 penetrating to the timing chain side from the hydraulic tensioner 80 side. The hydraulic tensioner 80 includes a tensioner main body part 81 into which oil is injected, and a plunger 84 slidably arranged at the tensioner main body part 81, and pressing the tensioner arm 70 to the timing chain by the hydraulic pressure of the oil which is injected into the tensioner main body part 81. The plunger 84 includes a cylinder part formed into a cylindrical shape, and filled with oil, a block plate for blocking the tensioner arm 70 side of the cylinder part, and a plunger hole 843 drilled at the block plate. The plunger hole 843 opposes a first opening part 741 of a penetration hole 74A.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a timing chain mechanism.

Background Art

[0002] Conventionally, as a timing chain mechanism, for example, Patent Document 1 discloses a control mechanism for an engine having a variable valve timing mechanism that varies the rotational phase of a camshaft with respect to a crankshaft. This engine control mechanism includes a measurement unit that measures the amount of tension correction by a hydraulic tensioner that corrects the tension of a timing chain that transmits power from the crankshaft to the camshaft, a deviation calculation unit that calculates a deviation from an initial state in the rotational angle of the camshaft with respect to the crankshaft based on the measurement result of the measurement unit, and a correction unit that corrects the deviation based on the calculation result of the deviation calculation unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the engine control mechanism described in Patent Document 1 above, for example, a hydraulic tensioner presses a timing chain via a tensioner arm, but there is room for further improvement in suppressing the friction between the tensioner arm and the timing chain with lubricating oil.

[0005] Therefore, the present invention has been made in view of the above, and an object thereof is to provide a timing chain mechanism that can be properly lubricated.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the timing chain mechanism according to the present invention comprises a timing chain that transmits power from the crankshaft to the camshaft, It is formed in the shape of a curved arm that rotates with one end as the pivot axis, The system comprises a tensioner arm that contacts the timing chain and applies tension to the timing chain, and a hydraulic tensioner that presses the tensioner arm against the timing chain using the hydraulic pressure of oil, wherein the tensioner arm is It is formed in a straight line along the shorter direction that intersects the longitudinal direction of the tensioner arm. The aforementioned hydraulic tensioner side opening From the timing chain side opening A through hole that penetrates through , in the center The hydraulic tensioner includes a main body into which oil is injected, and a plunger slidably provided in the main body and pressing the tensioner arm against the timing chain by the hydraulic pressure of the oil injected into the main body, wherein the plunger includes a cylindrical portion formed in a cylindrical shape and filled with oil, a closing plate that closes the tensioner arm side of the cylindrical portion, and a plunger hole drilled in the closing plate, the plunger hole being the through hole The hydraulic tensioner side It is characterized by being opposite the opening. [Effects of the Invention]

[0007] The timing chain mechanism according to the present invention allows the oil injected into the body of the hydraulic tensioner to be discharged to the tensioner arm and timing chain via the plunger hole and through hole when adjusting the tension of the timing chain by pressing the tensioner arm against the timing chain with a hydraulic tensioner. As a result, the timing chain mechanism can lubricate the tensioner arm and timing chain using the oil that drives the plunger, thereby enabling proper lubrication. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of the configuration of a timing chain mechanism according to the first embodiment. [Figure 2]Figure 2 is a perspective view showing an example configuration of a tensioner arm and a hydraulic tensioner according to the first embodiment. [Figure 3] Figure 3 is a cross-sectional view showing an example of the configuration of a hydraulic tensioner according to the first embodiment. [Figure 4] Figure 4 is a flowchart showing an example of the operation of a hydraulic tensioner according to the first embodiment. [Figure 5] Figure 5 is a schematic diagram showing an example of the configuration of a timing chain mechanism according to the second embodiment. [Modes for carrying out the invention]

[0009] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. Moreover, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0010] [First Embodiment] The timing chain mechanism 1 according to the first embodiment will be described with reference to the drawings. The timing chain mechanism 1 according to the first embodiment is installed in an engine (internal combustion engine) such as an automobile, and as shown in Figure 1, the rotation of the crankshaft Pa is transmitted by the timing chain 10 to the intake side camshaft Q1a and the exhaust side camshaft Q2a, causing the intake side camshaft Q1a and the exhaust side camshaft Q2a to rotate in a driven manner at a constant ratio to the rotation of the crankshaft Pa. As a result, the timing chain mechanism 1 can open and close the intake valve and exhaust valve of the engine at precise timing, and operate the engine in an appropriate combustion cycle. The timing chain mechanism 1 according to the first embodiment is characterized in that it properly lubricates the timing chain 10. The timing chain mechanism 1 will be described in detail below.

[0011] As shown in Figure 1, the timing chain mechanism 1 comprises a timing chain 10, a support arm 20, an oil discharge section 30, a tension sensor 40, a hydraulic circuit 50, an ECU (Electronic Control Unit) 60, a tensioner arm 70, and a hydraulic tensioner 80.

[0012] The timing chain 10 transmits power from the crankshaft Pa to the intake camshaft Q1a and the exhaust camshaft Q2a. The timing chain 10 is formed in an annular shape from metal members and is wrapped around the crank sprocket Pb fixed to the crankshaft Pa, the intake cam sprocket Q1b fixed to the intake camshaft Q1a, and the exhaust cam sprocket Q2b fixed to the exhaust camshaft Q2a. With the timing chain 10 wrapped around the crank sprocket Pb, the intake cam sprocket Q1b, and the exhaust cam sprocket Q2b, a predetermined tension is applied by the pressure of the tensioner arm 70, which will be described later. The timing chain 10 transmits the rotation of the crankshaft Pa to the intake camshaft Q1a and the exhaust camshaft Q2a, causing the intake camshaft Q1a and the exhaust camshaft Q2a to rotate in a constant ratio with respect to the rotation of the crankshaft Pa.

[0013] Next, the support arm 20 will be described. The support arm 20 supports the timing chain 10. The support arm 20 is formed in a curved arm shape and is provided on the opposite side of the timing chain 10 from the tensioner arm 70. The support arm 20 is fixed to the engine body (not shown) by an upper fixing part 22 provided on the upper side of its main body 21 and a lower fixing part 23 provided on the lower side of the main body 21. The support arm 20 brings the curved surface provided on the main body 21 of the support arm 20 into contact with the outside of the annular timing chain 10, and supports the annular timing chain 10 from the outside toward the tensioner arm 70. For example, the support arm 20 supports the annular timing chain 10 wrapped around the crank sprocket Pb, the intake side cam sprocket Q1b, and the exhaust side cam sprocket Q2b from the outside toward the tensioner arm 70.

[0014] Next, the oil discharge section 30 will be described. The oil discharge section 30 discharges oil (lubricating oil) to the crank sprocket Pb and the timing chain 10. The oil discharge section 30 is located inside the annular timing chain 10 and is positioned near the crank sprocket Pb. The oil discharge section 30 discharges oil to the crank sprocket Pb and the timing chain 10 that meshes with the crank sprocket Pb. As a result, the oil discharge section 30 can suppress friction between the crank sprocket Pb and the timing chain 10.

[0015] Next, the tension sensor 40 will be described. The tension sensor 40 detects the tension of the timing chain 10. The tension sensor 40 is, for example, a pressure sensor such as a load cell, which converts load into an electrical signal. The tension sensor 40 detects, for example, the reaction force (tension) that the hydraulic tensioner 80 receives from the tensioner arm 70. Note that the tension sensor 40 is not limited to the example of detecting the reaction force that the hydraulic tensioner 80 receives from the tensioner arm 70, but may also be, for example, one that directly detects the tension of the timing chain 10. The tension sensor 40 is connected to the ECU 60 and outputs the detected tension to the ECU 60.

[0016] Next, the hydraulic circuit 50 will be described. The hydraulic circuit 50 supplies oil to the hydraulic tensioner 80 and adjusts the hydraulic pressure of the hydraulic tensioner 80. The hydraulic circuit 50 is connected to the ECU 60 and the hydraulic tensioner 80, and the amount of oil supplied to the hydraulic tensioner 80 is adjusted by control from the ECU 60.

[0017] Next, the ECU 60 will be described. The ECU 60 controls the hydraulic circuit 50. The ECU 60 is connected to the tension sensor 40 and the hydraulic circuit 50, and controls the hydraulic circuit 50 based on the tension output from the tension sensor 40. For example, the ECU 60 compares the tension output from the tension sensor 40 with a predetermined reference tension. When the tension output from the tension sensor 40 is less than the reference tension, the ECU 60 controls the hydraulic circuit 50 to supply oil from the hydraulic circuit 50 to the hydraulic tensioner 80. On the other hand, when the tension output from the tension sensor 40 is greater than or equal to the reference tension, the ECU 60 controls the hydraulic circuit 50 to stop supplying oil from the hydraulic circuit 50 to the hydraulic tensioner 80.

[0018] Next, the tensioner arm 70 will be described. The tensioner arm 70 applies tension to the timing chain 10. As shown in FIG. 1, the tensioner arm 70 is formed in a curved arm shape and is provided on the opposite side of the support arm 20 with the timing chain 10 interposed therebetween. As shown in FIG. 2, the tensioner arm 70 includes an arm main body portion 71, a fixing portion 72, a contact surface 73, and a through hole 74.

[0019] The fixing portion 72 is provided on the lower end side of the arm main body portion 71 and is a portion fixed to the engine main body portion. Thereby, the arm main body portion 71 can rotate with the fixing portion 72 on the lower end side as a rotation axis. The contact surface 73 is a portion formed in a curved shape along the longitudinal direction of the arm main body portion 71. The contact surface 73 abuts against the outside of the annular timing chain 10. The tensioner arm 70 abuts the contact surface 73 against the outside of the annular timing chain 10, and rotates with the fixing portion 72 as a rotation axis by the pressing force received from the hydraulic tensioner 80, thereby pressing the annular timing chain 10 from the outside toward the support arm 20 side. For example, the tensioner arm 70 presses the annular timing chain 10 wound around the crank sprocket Pb, the intake side cam sprocket Q1b, and the exhaust side cam sprocket Q2b from the outside toward the support arm 20 side, and applies tension to the timing chain 10.

[0020] Here, the tensioner arm 70 includes a through hole 74. This through hole 74 penetrates from the hydraulic tensioner 80 side to the timing chain 10 side. In other words, the through hole 74 communicates from the hydraulic tensioner 80 side to the timing chain 10 side. The through hole 74 is located approximately in the center of the tensioner arm 70 in the longitudinal direction of the tensioner arm 70. The through hole 74 includes a first opening 741 provided on the hydraulic tensioner 80 side and a second opening 742 provided on the timing chain 10 side, and is formed in a straight line along the short direction intersecting the longitudinal direction of the tensioner arm 70. The diameter of the through hole 74 is about 5 mm, which is larger than the diameter of the plunger hole 843 of the hydraulic tensioner 80, which will be described later. The through hole 74 constitutes a passage for oil leaking from the hydraulic tensioner 80 to flow from the hydraulic tensioner 80 side to the timing chain 10 side.

[0021] Next, the hydraulic tensioner 80 will be described. The hydraulic tensioner 80 presses the tensioner arm 70 against the timing chain 10 using the hydraulic pressure of oil. The hydraulic tensioner 80 is positioned opposite the tensioner arm 70 and is located approximately in the center of the tensioner arm 70. As shown in Figure 3, the hydraulic tensioner 80 consists of a tensioner body 81 as the main body, a check ball 82, a leaf spring 83, and a plunger 84.

[0022] The tensioner body 81 supports the plunger 84 in a slidable manner. The tensioner body 81 is composed of a cylindrical portion 811, a bottom plate 812, and an opening hole 813.

[0023] The cylindrical portion 811 is formed in a cylindrical shape along the axial direction and has an internal space 810 on its inside. The cylindrical portion 811 has a bottom plate 812 on the side opposite to the plunger 84 in the axial direction, and one side of the cylindrical portion 811 is closed by the bottom plate 812. The cylindrical portion 811 is open on the side opposite to the bottom plate 812 in the axial direction, and the plunger 84 is provided in this opening.

[0024] The bottom plate 812 is formed in a plate shape and is provided on one side of the cylindrical portion 811 in the axial direction. The bottom plate 812 closes one side of the cylindrical portion 811 in the axial direction. The bottom plate 812 has an opening hole 813 perforated in it.

[0025] The opening 813 is connected to the oil inlet of the hydraulic circuit 50, and the oil supplied from the hydraulic circuit 50 is injected into the internal space 810 of the cylindrical portion 811 through the opening 813.

[0026] The check ball 82 opens and closes the opening 813 in the bottom plate 812. The check ball 82 is formed in a spherical shape, and its diameter is larger than the diameter of the opening 813. The check ball 82 closes the opening 813 by coming into contact with it, and opens the opening 813 by moving away from it.

[0027] The leaf spring 83 biases the check ball 82 toward the opening hole 813. When the oil pressure supplied from the hydraulic circuit 50 is less than the oil pressure in the internal space 810 of the cylindrical portion 811, the check ball 82 biased toward the opening hole 813 by the leaf spring 83 closes the opening hole 813 of the bottom plate 812. On the other hand, when the oil pressure supplied from the hydraulic circuit 50 is equal to or greater than the oil pressure in the internal space 810 of the cylindrical portion 811, the opening hole 813 of the bottom plate 812 opens.

[0028] The plunger 84 is slidably mounted on the tensioner body 81 and presses the tensioner arm 70 against the timing chain 10 by the hydraulic pressure of the oil injected into the tensioner body 81. The plunger 84 is composed of a cylindrical portion 841, a closing plate 842, and a plunger hole 843.

[0029] The cylindrical portion 841 is formed in a cylindrical shape along the axial direction and is slidably fitted into the internal space 810 of the tensioner body portion 81. The cylindrical portion 841 has a closing plate 842 on the side opposite to the tensioner body portion 81 in the axial direction, i.e., on the tensioner arm 70 side, and the tensioner arm 70 side is closed by the closing plate 842. The cylindrical portion 841 is open on the side opposite to the closing plate 842 in the axial direction.

[0030] The closing plate 842 is formed in a plate shape and closes the side of the cylindrical portion 841 opposite to the tensioner body portion 81 in the axial direction, i.e., the side facing the tensioner arm 70. The closing plate 842 has a plunger hole 843 perforated in it.

[0031] The plunger hole 843 is a hole drilled in the closing plate 842. The plunger hole 843 has a diameter of about 0.5 mm, which is smaller than the diameter of the through hole 74 (about 5 mm). As shown in Figure 2, the plunger hole 843 faces the first opening 741 of the through hole 74 of the tensioner arm 70. The plunger hole 843 releases oil to the outside in accordance with the oil pressure of the oil filled in the internal space 840 of the cylindrical portion 841, and plays a damping function that dampens (mitigates) excessive tension or looseness of the timing chain 10.

[0032] As described above, the plunger 84 slides toward the tensioner arm 70 due to the increase in the oil pressure of the oil filling the internal space 840 of the cylindrical portion 841, pressing the tensioner arm 70 against the timing chain 10. Also, the plunger 84 slides toward the opposite side of the tensioner arm 70 due to the decrease in the oil pressure of the oil filling the internal space 840 of the cylindrical portion 841, by a spring (not shown) that biases it toward the opposite side of the tensioner arm 70.

[0033] Next, an example of the operation of the timing chain mechanism 1 will be described with reference to Figure 4. In the timing chain mechanism 1, the tension sensor 40 detects the tension (reaction force) that the hydraulic tensioner 80 receives from the tensioner arm 70 and outputs the detected tension to the ECU 60 (step S1). The ECU 60 compares the tension output from the tension sensor 40 with the reference tension and determines whether the tension output from the tension sensor 40 is less than the reference tension (step S2). If the tension output from the tension sensor 40 is less than the reference tension (step S2; Yes), the ECU 60 controls the hydraulic circuit 50 to supply oil from the hydraulic circuit 50 to the hydraulic tensioner 80 (step S3). In the hydraulic tensioner 80, the hydraulic pressure of the oil filling the internal space 810 of the tensioner body 81 and the internal space 840 of the plunger 84 increases due to the oil supplied from the hydraulic circuit 50, causing the plunger 84 to slide toward the tensioner arm 70 (step S4). As a result, the hydraulic tensioner 80 can relatively increase the tension of the timing chain 10 via the tensioner arm 70, bringing it closer to the reference tension. At this time, the hydraulic tensioner 80 discharges the oil filling the internal space 840 of the plunger 84 through the plunger hole 843 to the through hole 74 of the tensioner arm 70, according to the hydraulic pressure of the oil. As a result, the hydraulic tensioner 80 can perform a damping function that dampens (mitigates) the overtightening of the timing chain 10 caused by rotational fluctuations of the crankshaft Pa. The through hole 74 of the tensioner arm 70 discharges the oil discharged through the plunger hole 843 to the tensioner arm 70 and the timing chain 10. This allows the timing chain mechanism 1 to lubricate the tensioner arm 70 and the timing chain 10 using the oil that drives the plunger 84.

[0034] In step S2 described above, if the tension output from the tension sensor 40 is greater than or equal to the reference tension (step S2; No), the ECU 60 controls the hydraulic circuit 50 to stop supplying oil from the hydraulic circuit 50 to the hydraulic tensioner 80 (step S5). When the oil supplied from the hydraulic circuit 50 is stopped, the hydraulic pressure of the oil filled in the internal space 810 of the tensioner body 81 and the internal space 840 of the plunger 84 decreases, and the plunger 84 slides to the opposite side from the tensioner arm 70 (step S6). As a result, the hydraulic tensioner 80 can relatively weaken the tension of the timing chain 10 via the tensioner arm 70 and bring it closer to the reference tension. At this time, the hydraulic tensioner 80 discharges the oil filled in the internal space 840 of the plunger 84 through the plunger hole 843 to the through hole 74 of the tensioner arm 70, according to the hydraulic pressure of the oil. As a result, the hydraulic tensioner 80 can perform a damping function that reduces (mitigates) excessive loosening of the timing chain 10 caused by rotational fluctuations of the crankshaft Pa. The through hole 74 of the tensioner arm 70 discharges oil discharged through the plunger hole 843 to the tensioner arm 70 and the timing chain 10. As a result, the timing chain mechanism 1 can lubricate the tensioner arm 70 and the timing chain 10 using the oil that drives the plunger 84.

[0035] As described above, the timing chain mechanism 1 according to the first embodiment comprises a timing chain 10, a tensioner arm 70, and a hydraulic tensioner 80. The timing chain 10 transmits power from the crankshaft Pa to the intake side camshaft Q1a and the exhaust side camshaft Q2a. The tensioner arm 70 abuts against the timing chain 10 and applies tension to the timing chain 10. The hydraulic tensioner 80 presses the tensioner arm 70 against the timing chain 10 by the hydraulic pressure of the oil. Here, the tensioner arm 70 includes a through hole 74 that penetrates from the hydraulic tensioner 80 side to the timing chain 10 side. The hydraulic tensioner 80 includes a tensioner body 81 into which oil is injected, and a plunger 84 slidably provided in the tensioner body 81 and presses the tensioner arm 70 against the timing chain 10 by the hydraulic pressure of the oil injected into the tensioner body 81. The plunger 84 includes a cylindrical portion 841 formed in a cylindrical shape and filled with oil, a closing plate 842 that closes the tensioner arm 70 side of the cylindrical portion 841, and a plunger hole 843 drilled in the closing plate 842, the plunger hole 843 facing the first opening 741 of the through hole 74.

[0036] With this configuration, when the timing chain mechanism 1 adjusts the tension of the timing chain 10 by pressing the tensioner arm 70 against the timing chain 10 with the hydraulic tensioner 80, the oil injected into the tensioner body 81 of the hydraulic tensioner 80 can be discharged to the tensioner arm 70 and the timing chain 10 via the plunger hole 843 and the through hole 74. In particular, when the tension of the timing chain 10 is relatively increased, the tensioner arm 70 is strongly pushed towards the timing chain 10, and the friction load between the contact surface 73 of the tensioner arm 70 and the timing chain 10 becomes relatively higher. In this case, the hydraulic tensioner 80, with its increased hydraulic pressure, can discharge more oil from the through hole 74 to the tensioner arm 70 and the timing chain 10, making it more effective. Furthermore, conventionally, the large centrifugal force of the crank sprocket Pb can cause oil to splash around the crank sprocket Pb, resulting in insufficient lubrication of the tensioner arm 70 located after the crank sprocket Pb. The timing chain mechanism 1 can lubricate the tensioner arm 70 and the timing chain 10 even in such cases by utilizing the oil that drives the plunger 84 of the hydraulic tensioner 80. As a result, the timing chain mechanism 1 can be properly lubricated.

[0037] The timing chain mechanism 1 described above further includes a crank sprocket Pb provided on the crankshaft Pa, and an oil discharge section 30 that discharges oil to the timing chain 10 that meshes with the crank sprocket Pb. With this configuration, the timing chain mechanism 1 can further suppress friction between the crank sprocket Pb and the timing chain 10 by means of the oil discharge section 30.

[0038] In the above description, the hydraulic tensioner 80 and the through-hole 74 were described as being located approximately in the center of the tensioner arm 70, but the description is not limited to this, and for example, they may be located at the upper end of the tensioner arm 70.

[0039] [Second Embodiment] Next, the timing chain mechanism 1A according to the second embodiment will be described with reference to Figure 5. In the second embodiment, components equivalent to those in the first embodiment are denoted by the same reference numerals, and their detailed descriptions are omitted. The timing chain mechanism 1A according to the second embodiment differs from the timing chain mechanism 1 according to the first embodiment in that the tensioner arm 70A rotates around the upper end fixing portion 72A as a pivot axis, and the hydraulic tensioner 80 and through hole 74A are provided on the opposite side (lower end side) from the upper end fixing portion 72A.

[0040] As shown in Figure 5, the timing chain mechanism 1A comprises a timing chain 10, a support arm 20, a tension sensor 40, a hydraulic circuit 50, an ECU 60, a tensioner arm 70A, and a hydraulic tensioner 80.

[0041] The tensioner arm 70A applies tension to the timing chain 10. The tensioner arm 70A is formed in a curved arm shape and is located on the opposite side of the timing chain 10 from the support arm 20. The tensioner arm 70A consists of an arm body portion 71A, a fixing portion 72A, a contact surface 73A, and a through hole 74A.

[0042] The fixing portion 72A is provided on the upper end side of the arm body portion 71A and is fixed to the engine body. This allows the arm body portion 71A to rotate around the fixing portion 72A on the upper end side as a pivot axis. The contact surface 73A is a portion formed in a curved shape along the longitudinal direction of the arm body portion 71A. The contact surface 73A contacts the outside of the annular timing chain 10. The tensioner arm 70A contacts the outside of the annular timing chain 10 with its contact surface 73A in contact and rotates around the fixing portion 72A as a pivot axis due to the pressing force received from the hydraulic tensioner 80, thereby pressing the annular timing chain 10 from the outside toward the support arm 20. The tensioner arm 70A presses the annular timing chain 10, which is wrapped around the crank sprocket Pb, the intake cam sprocket Q1b, and the exhaust cam sprocket Q2b, from the outside toward the support arm 20, thereby applying tension to the timing chain 10.

[0043] Here, the tensioner arm 70A includes a through hole 74A. This through hole 74A penetrates from the hydraulic tensioner 80 side to the timing chain 10 side. In other words, the through hole 74A communicates from the hydraulic tensioner 80 side to the timing chain 10 side. The through hole 74A is provided on the lower end side of the tensioner arm 70A in the longitudinal direction of the tensioner arm 70A. The through hole 74A includes a first opening 741 provided on the hydraulic tensioner 80 side and a second opening 742 provided on the timing chain 10 side, and is formed linearly along the short direction intersecting the longitudinal direction of the tensioner arm 70A. The through hole 74A constitutes a passage through which oil leaking from the hydraulic tensioner 80 flows from the hydraulic tensioner 80 side to the timing chain 10 side.

[0044] The hydraulic tensioner 80 has a plunger hole 843 facing the first opening 741 of the through hole 74A of the tensioner arm 70. The hydraulic tensioner 80 discharges oil from the internal space 840 of the plunger 84 to the through hole 74A of the tensioner arm 70 via the plunger hole 843, according to the hydraulic pressure of the oil. In this way, the hydraulic tensioner 80 can perform a damping function to dampen (mitigate) excessive tension or looseness of the timing chain 10. The through hole 74A of the tensioner arm 70 discharges the oil discharged via the plunger hole 843 to the tensioner arm 70A, the timing chain 10, and the crank sprocket Pb. In this way, the timing chain mechanism 1A can lubricate the tensioner arm 70A and the timing chain 10 using the oil that drives the plunger 84, and can also lubricate the crank sprocket Pb. As a result, the timing chain mechanism 1A can omit the oil discharge section 30 according to the first embodiment, thereby suppressing an increase in the number of parts. [Explanation of Symbols]

[0045] 1 Timing chain mechanism 10 Timing chain 30 Oil discharge section 70, 70A Tensioner Arm 74, 74A through hole 80 Hydraulic Tensioner 81 Tensioner body (body part) 84 Plungers 841 Cylinder part 842 Occlusion plate 843 Plunger hole Pa crankshaft Q1a Intake side camshaft (camshaft) Q2a Exhaust side camshaft (camshaft)

Claims

1. A timing chain that transmits power from the crankshaft to the camshaft, A tensioner arm is formed in the shape of a curved arm that rotates with one end as a pivot axis, and which contacts the timing chain to apply tension to the timing chain, The system includes a hydraulic tensioner that presses the tensioner arm against the timing chain using the hydraulic pressure of oil, The tensioner arm is formed linearly along the short direction intersecting the longitudinal direction of the tensioner arm, and includes a through hole in its central part that penetrates from the opening on the hydraulic tensioner side to the opening on the timing chain side. The hydraulic tensioner includes a main body into which oil is injected, and a plunger slidably provided in the main body and which presses the tensioner arm against the timing chain by the hydraulic pressure of the oil injected into the main body. The timing chain mechanism is characterized in that the plunger includes a cylindrical portion formed in a cylindrical shape and filled with oil, a closing plate that closes the tensioner arm side of the cylindrical portion, and a plunger hole drilled in the closing plate, wherein the plunger hole faces the opening of the through hole on the hydraulic tensioner side.

2. The timing chain mechanism according to claim 1, further comprising a crank sprocket provided on the crankshaft and an oil discharge unit for discharging oil to the timing chain meshed with the crank sprocket.

Images