Valve train structure of an internal combustion engine using lash adjusters

Abstract

To provide a dynamic valve structure of an internal combustion engine which can prevent falling of lash adjusters from an arm part of a holding tee, and can improve workability in assembling a valve and the holding tee.SOLUTION: A dynamic valve system structure comprises: a valve arm which oscillates with an axis as a center; a holding tee (30) whose apex (30a) is attached to an end part (20a) of the valve arm so as to be turnable; a valve (40) which opens and closes by moving in an axial direction according to the oscillation of the valve arm; and lash adjusters (50A, 50B) attached to the arm part (32) of the holding tee (30), and coming into contact with an end part (41a) of the valve (40) on the holding tee (30) side. A stopper (60) for preventing falling of the lash adjusters (50A, 50B) from the arm part (32) of the holding tee (30) is attached to the lash adjusters (50A, 50B).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a valve train structure of an internal combustion engine for using a lash adjuster.

Background Art

[0002] As a conventional valve train structure of an internal combustion engine, there is one including a valve arm that swings about an axis, a retainer that is rotatably attached to the end of the valve arm at the top, and a valve that moves axially to open and close in response to the swing of the valve arm (see, for example, Patent Document 1). Further, the above conventional valve train structure includes a piston that is attached to the arm portion of the retainer and contacts the end of the valve on the retainer side. In the above conventional valve train structure, the valve clearance is adjusted by the piston.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional valve train structure, it is conceivable to use a lash adjuster instead of the piston. When the piston is replaced with a lash adjuster in the above conventional valve train structure, there is a risk that the lash adjuster may fall off from the arm portion of the retainer, and the workability when assembling the valve and the retainer may be reduced.

[0005] An object of the present invention is to provide a valve train structure of an internal combustion engine that can prevent the lash adjuster from falling off from the arm portion of the retainer and can improve the workability when assembling the valve and the retainer.

Means for Solving the Problems

[0006] One aspect of the present invention is, Valve arms that oscillate around an axis, A retaining tee whose top is rotatably attached to the end of the valve arm, A valve that moves axially to open and close in response to the oscillation of the valve arm, A lash adjuster is attached to the arm portion of the above-mentioned retaining tee and contacts the end of the above-mentioned valve on the retaining tee side. Equipped with, The present invention provides a valve train structure for an internal combustion engine that uses a stopper to prevent the lash adjuster from falling off the arm portion of the retaining tee.

[0007] This configuration includes a stopper to prevent the lash adjuster from falling off the arm of the retaining tee, thus preventing the lash adjuster from falling off the arm of the retaining tee. This improves the workability when assembling the valve and the retaining tee.

[0008] In one embodiment, the retaining tee is provided with an oil passage for guiding oil to the lash adjuster.

[0009] In one embodiment, an air vent hole is provided that communicates with the oil passage and is located on the lash adjuster.

[0010] In the above embodiment, since an air vent hole communicating with an oil passage that guides oil to the lash adjuster is located on the lash adjuster, air can be removed from the oil supplied to the lash adjuster, and air can be prevented from getting trapped in the lash adjuster. [Effects of the Invention]

[0011] According to the present invention, it is possible to prevent the lash adjuster from falling off the arm portion of the retaining tee, and to improve workability when assembling the valve and the retaining tee. [Brief explanation of the drawing]

[0012] [Figure 1]Schematic configuration diagram for explaining the valve train structure of a marine gas engine according to the first embodiment of the present invention. [Figure 2] Cross-sectional view of the main part of the valve train structure according to the first embodiment of the present invention. [Figure 3] Cross-sectional view of the main part of the valve train structure according to the second embodiment of the present invention. [Figure 4] Plan view (a) and side view (b) of the main part of the valve train structure according to the third embodiment of the present invention. [Figure 5] Side view (a) and bottom view (b) of the main part of the valve train structure according to the fourth embodiment of the present invention. [Figure 6] Side view of the main part of the valve train structure according to the fifth embodiment of the present invention. [Figure 7] Schematic configuration diagram according to a modified example of the present invention.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0014] (First Embodiment) FIG. 1 is a schematic configuration diagram for explaining the valve train structure 1 of a marine gas engine according to the first embodiment of the present invention. In FIG. 1, a part is shown in cross section. Further, FIG. 2 is an enlarged view of the main part of the valve train structure 1 according to the first embodiment. The marine gas engine according to the present embodiment is an example of an internal combustion engine according to the present invention.

[0015] Referring to FIG. |, the valve train structure 1 according to the present embodiment includes a cylinder head 10, a valve arm 20, a retainer 30, valves 40A and 40B, and lash adjusters 50A and 50B. In the following description, when it is not necessary to particularly distinguish between the valves 40A and 40B, one of them may be simply referred to as the valve 40. Also, in the following description, when it is not necessary to particularly distinguish between the lash adjusters 50A and 50B, one of them may be simply referred to as the lash adjuster 50.

[0016] The cylinder head 10 defines a part of a combustion chamber (not shown). The cylinder head 10 is provided with a retainer guide 11 that supports the retainer 30. The cylinder head 10 is provided with valve guides 12A and 12B. A stem 41 of a valve 40A, which will be described later, is inserted through the valve guide 12A. A stem 41 of a valve 40B is inserted through the valve guide 12B. In the following description, when there is no need to particularly distinguish between the valve guides 12A and 12B, one of them may be simply referred to as the valve guide 12.

[0017] Inside the cylinder head 10 and the retainer guide 11, an oil supply passage 13 for supplying oil to the retainer 30 is provided. Also, an oil supply port 14 is provided on the side surface of the cylinder head 10. The oil supply passage 13 is connected to an external oil supply source (not shown) via the oil supply port 14. The oil supplied from the oil supply port 14 to the oil supply passage 13 passes through the inside of the cylinder head 10 and then through the inside of the retainer guide 11, and is supplied to the retainer 30.

[0018] The valve arm 20 is supported by a shaft 21. The valve arm 20 is rotatable about the shaft 21. The top 30a of the retainer 30 is attached to one end 20a of the valve arm 20. A push rod 22 is attached to the other end 20b of the valve arm 20. The push rod 22 is attached to the cylinder head 10 so as to be axially movable. When the push rod 22 moves axially, the valve arm 20 swings about the shaft 21.

[0019] The top 30a of the retainer 30 is rotatably attached to the end 20a of the valve arm 20. Referring also to FIG. 2, the retainer 30 includes a body portion 31 and arm portions 32A and 32B. In the following description, when there is no need to distinguish between the arm portions 32A and 32B, one of them may be simply referred to as the arm portion 32.

[0020] The body portion 31 is cylindrical. The inner diameter of the body portion 31 is slightly smaller than the outer diameter of the retaining tee guide 11. The retaining tee guide 11, which is provided on the cylinder head 10, is inserted through the body portion 31. As a result, the retaining tee 30 is supported by the retaining tee guide 11. Furthermore, the retaining tee 30 can move linearly in the axial direction of the retaining tee guide 11 while being guided by the retaining tee guide 11.

[0021] The arm portion 32 extends laterally from the body portion 31. In other words, the arm portion 32 extends radially around the axis of the body portion 31. A lash adjuster 50 is attached to the arm portion 32.

[0022] The retaining tee 30 is provided with an oil chamber 33 for containing oil. The oil chamber 33 is defined by the inner circumferential surface of the body 31 and the retaining tee guide 11. The oil chamber 33 communicates with an oil supply passage 13 (shown in Figure 1) provided within the retaining tee guide 11. As a result, oil is supplied to the oil chamber 33 via the oil supply passage 13.

[0023] The retaining tee 30 is provided with an oil passage 34 that guides oil to the lash adjuster 50, and an air vent hole 35 that communicates with the oil passage 34 and is located on the lash adjuster 50.

[0024] The oil passage 34 is connected to the oil chamber 33. The oil in the oil chamber 33 is guided to the lash adjuster 50 via the oil passage 34.

[0025] The retaining tee 30 is provided with a discharge hole 36 for discharging oil from the oil passage 34. The oil passage 34 and the outside of the retaining tee 30 are in communication via the discharge hole 36. The discharge hole 36 is located above the retainer 42 (shown in Figure 1), which will be described later, of the valve 40. As a result, the oil discharged through the discharge hole 36 is supplied to the valve 40.

[0026] As shown in Figure 1, the valve 40 comprises a stem 41 and a retainer 42 fixed to the stem 41. The stem 41 opens and closes an intake port (not shown) or an exhaust port (not shown) provided in the cylinder head 10.

[0027] The stem 41 is inserted through a valve guide 12 provided in the cylinder head 10. This allows the valve 40 to move linearly in the axial direction of the stem 41 while being guided by the valve guide 12. The valve 40 moves axially in response to the oscillation of the valve arm 20, opening and closing the intake port or exhaust port.

[0028] A spring 43 is positioned between the retainer 42 and the cylinder head 10. The spring 43 is positioned between the valve 40 and the cylinder head 10 in a compressed state. The valve 40 is biased in the direction of closing the intake port or exhaust port by the restoring force of the spring 43.

[0029] As shown in Figure 2, the lash adjuster 50 is attached to the arm portion 32 of the retaining tee 30. The lash adjuster 50 also contacts the end portion 41a of the valve 40 on the retaining tee 30 side. The lash adjuster 50 is a component for automatically adjusting the valve clearance to zero.

[0030] The lash adjuster 50 comprises a body 51, a plunger 52, a spring 53, and a check ball 54.

[0031] The body 51 is a bottomed cylindrical shape. As clearly shown in Figure 2, an outer circumferential groove 51a is provided on the outer circumferential surface of the body 51 in this embodiment. The outer circumferential groove 51a is formed as a recess from the outer circumferential surface of the body 51. The bottom of the body 51 is in contact with the end 41a of the valve 40 on the retaining tee 30 side.

[0032] The plunger 52 is a bottomed cylindrical shape. The plunger 52 is inserted into the body 51. The outer diameter of the plunger 52 is approximately the same as the inner diameter of the body 51. The plunger 52 is movable relative to the body 51. A communication hole 52a is provided at the bottom of the plunger 52. The space inside the plunger 52 and the high-pressure chamber 55, which will be described later, are in communication with each other via the communication hole 52a.

[0033] The body 51 and the plunger 52 define a high-pressure chamber 55. The high-pressure chamber 55 contains high-pressure oil guided to the lash adjuster 50 via the oil passage 34. The high-pressure chamber 55 communicates with the space inside the plunger 52 through a communication hole 52a provided in the plunger 52.

[0034] The spring 53 is located within the high-pressure chamber 55. The spring 53 is positioned in a compressed state between the body 51 and the plunger 52. The body 51 and the plunger 52 are biased to move away from each other by the restoring force of the spring 53. In other words, the body 51 and the plunger 52 are biased by the restoring force of the spring 53 to increase the length of the lash adjuster 50.

[0035] The check ball 54 is held in place by a retaining member (not shown). The check ball 54 blocks the communication hole 52a, preventing liquid from leaking from the high-pressure chamber 55 into the plunger 52 through the communication hole 52a. On the other hand, when the oil pressure in the plunger 52 becomes higher than the oil pressure in the high-pressure chamber 55, the check ball 54 moves away from the communication hole 52a, creating communication between the space inside the plunger 52 and the high-pressure chamber 55. Oil flows from the plunger 52 into the high-pressure chamber 55, and the body 51 and the plunger 52 move away from each other so that the volume of the high-pressure chamber 55 increases. As a result, the length of the lash adjuster 50 increases, and the valve clearance is adjusted.

[0036] As clearly shown in Figure 2, the lash adjuster 50 is fitted with a stopper 60 to prevent it from falling off the arm portion 32 of the retaining tee 30. The stopper 60 in this embodiment allows relative movement of the body 51 with respect to the plunger 52, while preventing the lash adjuster 50 from falling off the retaining tee 30. The stopper 60 in this embodiment is a spring clip positioned across the outer peripheral groove 51a provided on the outer peripheral surface of the body 51 and the stepped portion 37 provided inside the retaining tee 30. One end of the stopper 60 is positioned in the outer peripheral groove 51a, and the other end of the stopper 60 is supported by the stepped portion 37. The stopper 60 restricts the downward movement of the body 51 (towards the bottom in Figure 2). More specifically, the downward movement of the body 51 is restricted by the contact between the wall 51b defining the upper side of the outer peripheral groove 51a and the stopper 60. This prevents the lash adjuster 50 from falling off the retaining tee 30.

[0037] The valve train structure 1 according to this embodiment has the following functions.

[0038] Since a stopper 60 is used to prevent the lash adjuster 50 from falling off the arm portion 32 of the retaining tee 30, it is possible to prevent the lash adjuster 50 from falling off the arm portion 32 of the retaining tee 30. For example, it is possible to prevent the lash adjuster 50 from falling off the arm portion 32 due to its own weight. This improves the workability when assembling the valve 40 and the retaining tee 30.

[0039] Since the air vent hole 35, which communicates with the oil passage 34 that guides oil to the lash adjuster 50, is located on the lash adjuster 50, air can be removed from the oil supplied to the lash adjuster 50, thereby preventing air from getting trapped in the lash adjuster.

[0040] (Second Embodiment) Figure 3 is a cross-sectional view of the main part of the valve train structure 101 according to the second embodiment. The valve train structure 101 according to the second embodiment has the same configuration as the valve train structure 1 according to the first embodiment, except for a structure to prevent the lash adjuster 150 from falling off the arm portion 132 of the retaining tee 130. In the second embodiment, components the same as in the first embodiment are denoted by the same reference numerals, and their detailed description is omitted.

[0041] Referring to Figure 3, in this embodiment, the plunger 152 is fixed to the retaining tee 130, and the body 151 is prevented from coming off the plunger 152 by the stopper 160, thereby preventing the lash adjuster 150 from falling off the retaining tee 130. The stopper 160 in this embodiment allows relative movement of the body 151 with respect to the plunger 152, while preventing the lash adjuster 150 from falling off the retaining tee 130.

[0042] In this embodiment, the plunger 152 is mechanically connected to the retaining tee 130. More specifically, the male threaded portion 152b provided on the plunger 152 and the female threaded portion 132a provided on the arm portion 132 are mechanically connected. As a result, the plunger 152 is fixed to the retaining tee 130.

[0043] In this embodiment, the body 151 is prevented from coming off the plunger 152 by a stopper 160. The stopper 160 in this embodiment is a spring clip positioned between an inner groove 151a provided on the inner circumferential surface of the body 151 and an outer groove 152c provided on the outer circumferential surface of the plunger 152. One end of the stopper 160 is positioned in the inner groove 151a, and the other end of the stopper 160 is positioned in the outer groove 152c. The stopper 160 restricts the downward movement of the body 151 (downward in Figure 3). More specifically, the downward movement of the body 151 is restricted by the contact between the wall 151b defining the upper side of the inner groove 151a and the stopper 160.

[0044] The valve train structure 101 of this embodiment has the same function as the valve train structure 1 of the first embodiment.

[0045] (Third embodiment) Figure 4(a) is a plan view of the main part of the valve train structure 201 according to the third embodiment, viewed from above. Figure 4(b) is a side view of the main part of the valve train structure 201 according to the third embodiment. The valve train structure 201 according to the third embodiment has the same configuration as the valve train structure 1 according to the first embodiment, except for a structure to prevent the lash adjuster 50 from falling off the arm portion 232 of the retaining tee 230. In the third embodiment, components similar to those in the first embodiment are denoted by the same reference numerals, and their detailed description is omitted.

[0046] Referring to Figure 4, in this embodiment, a U-shaped stopper 260 can be attached to the arm portion 232 of the retaining tee 230. The stopper 260 comprises a pair of support portions 261 extending parallel to each other, and a semicircular connecting portion 262 that connects the ends of the pair of support portions 261 to each other. The retaining tee 230 is provided with a hole 230b through which the pair of support portions 261 of the stopper 260 are inserted. The support portions 261 are located in an outer peripheral groove 51a provided on the outer peripheral surface of the body 51. The support portions 261 abut against a wall 51b that defines the upper side of the outer peripheral groove 51a of the body 51, thereby restricting the downward movement of the body 51. This prevents the lash adjuster 50 from falling off the arm portion 232 of the retaining tee 230.

[0047] The valve train structure 201 of this embodiment has the same function as the valve train structure 1 of the first embodiment.

[0048] (Fourth Embodiment) Figure 5(a) is a side view of the main part of the valve train structure 301 according to the fourth embodiment. Figure 5(b) is a bottom view of the main part of the valve train structure 301 according to the fourth embodiment. The valve train structure 301 according to the fourth embodiment has the same configuration as the valve train structure 1 according to the first embodiment, except for a structure to prevent the lash adjuster 50 from falling off the arm portion 32 of the retaining tee 30. In the fourth embodiment, components the same as in the first embodiment are denoted by the same reference numerals, and their detailed description is omitted.

[0049] Referring to Figure 5, in this embodiment, a pair of stoppers 360 are fixed to the lower end face of the arm portion 32 of the retaining tee 30. More specifically, the stoppers 360 are fixed to the lower end face of the arm portion 32 by bolts 361. The stoppers 360 in this embodiment are arc-shaped. The stoppers 360 are positioned in an outer peripheral groove 51a provided on the outer peripheral surface of the body 51. The stoppers 360 contact a wall 51b that defines the upper side of the outer peripheral groove 51a of the body 51, thereby restricting the downward movement of the body 51. This prevents the lash adjuster 50 from falling off the arm portion 32 of the retaining tee 30.

[0050] The valve train structure 301 of this embodiment has the same function as the valve train structure 1 of the first embodiment.

[0051] (Fifth embodiment) Figure 6 is a side view of the valve train structure 401 according to the fifth embodiment. The valve train structure 1 according to the fifth embodiment has the same configuration as the valve train structure 1 according to the first embodiment, except for a structure to prevent the lash adjuster 450 from falling off the arm portion 32 of the retaining tee 30. In the fifth embodiment, components similar to those in the first embodiment are denoted by the same reference numerals, and their detailed description is omitted. The lash adjuster 450 of this embodiment has the same configuration as the lash adjuster 50 of the first embodiment, except that the body 451 does not have an outer circumferential groove.

[0052] Referring to Figure 6, the stopper 460 in this embodiment is a clip that clamps the retaining tee 30 and the lash adjuster 450 from above and below. In a side view, the stopper 460 in this embodiment is U-shaped. The stopper 460 in this embodiment supports the body 51 from below. This prevents the lash adjuster 450 from falling off the arm portion 32 of the retaining tee 30.

[0053] The valve train structure 401 of this embodiment has the same function as the valve train structure 1 of the first embodiment.

[0054] Although specific embodiments of this invention have been described, this invention is not limited to the first to fifth embodiments described above, and can be implemented with various modifications within the scope of this invention. For example, one embodiment of this invention may be an appropriate combination of the contents described in the first to fifth embodiments described above.

[0055] For example, as shown in the modified example in Figure 7, the oil supply passage 13 may be provided inside the cylinder head 10 and the valve arm 20. In this case, the oil supplied from the oil supply port 14 to the oil supply passage 13 passes through the inside of the cylinder head 10, then through the inside of the valve arm 20, and is supplied to the retaining tee 30. In other words, oil may be supplied to the retaining tee 30 from the valve arm 20. [Explanation of Symbols]

[0056] 1. Valve train structure 10 Cylinder head 11. Tee guide 12, 12A, 12B valve guide 13 Oil supply passage 14 Oil supply port 20 valve arms 20a End 20b end 21 axes 22 Pushrods 30 Pressing Tee 30a top 31 Torso 32, 32A, 32B Arm section 33 Oil room 34 Oil passage 35 Air vent holes 36 Exhaust hole 37 Step part 40, 40A, 40B valves 41 Stem 41a End 42 Retainers 43 Spring 50, 50A, 50B Lash Adjuster 51 Body 51a Outer groove 51b wall 52 Plungers 52a Communication hole 53 Spring 54 Check Ball 60 Stopper 101 Valve train structure 130 Pressing Tee 132 Arm section 132a Female thread section 150 Lash Adjuster 151 Body 151a Inner Circumferential Groove 151b Wall 152 Plunger 152b Male threaded section 152c outer groove 160 Stopper 201 Valve train structure 230 Pressing Tee 230b hole 232 Arm section 260 Stopper 261 Support part 262 Connection part 301 Valve train structure 360 Stopper 401 Valve train structure 450 Lash Adjuster 451 Body 460 Stopper

Claims

1. Valve arms that oscillate around an axis, A retaining tee whose top is rotatably attached to the end of the valve arm, A valve that moves axially to open and close in response to the oscillation of the valve arm, A lash adjuster is attached to the arm portion of the above-mentioned retaining tee and contacts the end of the above-mentioned valve on the retaining tee side. Equipped with, A stopper is used to prevent the lash adjuster from falling off the arm portion of the retaining tee. The valve train structure of an internal combustion engine, wherein the stopper is a spring clip positioned between an outer groove provided on the outer circumferential surface of the body of the lash adjuster and a stepped portion provided inside the arm portion.

2. The valve train structure for an internal combustion engine according to claim 1, wherein the retaining tee is provided with an oil passage for guiding oil to the lash adjuster.

3. The valve train structure of an internal combustion engine according to claim 2, wherein an air vent hole is provided that communicates with the oil passage and is located on the lash adjuster.

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