WO2020195718A1

WO2020195718A1 - Cam chain tensioner device

Info

Publication number: WO2020195718A1
Application number: PCT/JP2020/009758
Authority: WO
Inventors: 親司滝口; 悠平村木
Original assignee: 本田技研工業株式会社
Priority date: 2019-03-27
Filing date: 2020-03-06
Publication date: 2020-10-01
Also published as: JPWO2020195718A1; JP7197682B2

Abstract

Provided is a cam chain tensioner device that bleeds air at the stage of oil supply, thus suppressing the inclusion of air in a high-pressure chamber, and that can efficiently bleed air. A chain tensioner (31) includes a high pressure chamber (51), a low-pressure chamber (52), and a low-pressure-chamber communication passage (54A). The high-pressure chamber (51) allows a plunger (41), which serves as a pressing member for pressing a chain tensioner guide (28), to generate a pressing force; the low-pressure chamber (52) supplies oil to the high-pressure chamber (51); and the low-pressure-chamber communication passage (54A) communicates from the low-pressure chamber (52) to the inside of an engine (specifically, to a cam chain chamber 13a).

Description

Cam chain tensioner device

The present invention relates to a cam chain tensioner device.

Conventionally, it is known that air is not evacuated directly from the oil supply chamber, but is bleeded through a high pressure chamber maintained at a high pressure in order to press the chain tensioner via a cam chain tensioner guide (for example, Patent Document 1). reference).

Japanese Patent No. 6310335

In Patent Document 1, since air is bleeded through the high-pressure chamber, the air bleeding path becomes long, which hinders efficient discharge.
An object of the present invention is to provide a cam chain tensioner device capable of bleeding air at the stage of oil supply, suppressing air from entering the high-pressure chamber, and bleeding air efficiently.

This specification includes all the contents of the Japanese patent application / Japanese Patent Application No. 2019-061349 filed on March 27, 2019.
The cam chain tensioner device includes a chain tensioner guide (28) that slides on a cam chain (27) that transmits the rotational force of the crankshaft (11) of the engine (10) to the camshaft (25), and the chain tensioner guide (28). In a cam chain tensioner device including a chain tensioner (31) that hydraulically presses 28), the chain tensioner (31) generates a pressing force on a pressing member (41) that presses the chain tensioner guide (28). A high-pressure chamber (51) to be operated, an oil supply chamber (52) for supplying oil to the high-pressure chamber (51), and a communication passage (54A) communicating from the oil supply chamber (52) into the engine (10). It is characterized by having.

In the above configuration, the communication passage (54A) may have an opening (21q) that opens toward the chain tensioner guide (28).
Further, in the above configuration, the opening (21q) may be located above the contact point (48) between the chain tensioner guide (28) and the chain tensioner (31).

Further, in the above configuration, the chain tensioner (31) has a filter (34e) provided on the upstream side of the oil supply chamber (52) for filtering oil, and the filter (34e) is the filter (34e). It may be composed of a gasket (34) provided in the chain tensioner (31).

Further, in the above configuration, the chain tensioner (31) is provided on the upper surface of a cylinder portion (13) horizontally extending from the crankcase (12) of the engine (10) to parts other than the chain tensioner (31). An oil supply passage (21d) is provided that branches off from the horizontally extending horizontal oil passage (18c) used for oil refueling and extends to the filter (34e), and the oil supply passage (21d) is formed in a straight line and described above. The filter (34e) and the horizontal oil passage (18c) may be connected.

Further, in the above configuration, the oil supply port (36e) for supplying oil to the oil supply chamber (52) and the discharge port (36f) connected from the oil supply chamber (52) to the communication passage (54A) are the same. It may be provided on the same axis as the member.
Further, in the above configuration, the discharge port (36f) may be arranged higher than the refueling port (36e).

Further, in the above configuration, in the oil passage (36c) connecting the filter (34e) and the oil filler port (36e) side, one side end portion (36k) facing the filter (34e) is the other side end portion. It may be arranged higher than (36r).

The cam chain tensioner device is a series in which the chain tensioner communicates with a high-pressure chamber that generates pressing force on a pressing member that presses the chain tensioner guide, an oil supply chamber that supplies oil to the high-pressure chamber, and an oil supply chamber into the engine. Since it is provided with a passage, air can be bleeded from the oil supply chamber, air can be suppressed from being mixed into the high pressure chamber, and air can be bleeded efficiently.

In the above configuration, since the connecting passage has an opening that opens toward the chain tensioner guide, the oil discharged from the connecting passage is supplied to the chain tensioner guide to refuel the cam chain via the chain tensioner guide. it can.
Further, in the above configuration, since the opening is located above the contact point between the chain tensioner guide and the chain tensioner, oil can be supplied to the contact point and wear of the contact point can be suppressed.

Further, in the above configuration, the chain tensioner has a filter provided on the upstream side of the oil supply chamber for filtering the oil, and since the filter is composed of a gasket provided in the chain tensioner, a filter using a gasket is used. Therefore, the number of parts can be reduced.

Further, in the above configuration, the chain tensioner is provided on the upper surface of the cylinder portion extending horizontally from the crank case of the engine, and branches from the horizontally extending horizontal oil passage used for oil supply to parts other than the chain tensioner to the filter. An extending oil supply passage is provided, and the oil supply passage is formed in a straight line to connect the filter and the horizontal oil passage. Therefore, the oil mixed with the oil flowing from the horizontal oil passage side and accumulated in the filter is oil due to the engine stop or the like. When the flow of the filter stops, it separates from the filter and flows through the horizontal oil passage when the engine is restarted. Therefore, the number of times the filter is cleaned can be reduced and the maintainability of the chain tensioner can be improved.

Further, in the above configuration, the oil supply port for supplying oil to the oil supply chamber and the discharge port for connecting the oil supply chamber to the communication passage are provided on the same axis as the same member, so that the number of parts can be reduced. It is possible to improve workability.
Further, in the above configuration, since the discharge port is arranged higher than the oil supply port, air can be easily discharged from the oil supply chamber through the discharge port.

Further, in the above configuration, in the oil passage connecting the filter and the oil filler port side, one end facing the filter is arranged higher than the other end, so that the oil supply chamber from the filter side through the oil passage. It can make it difficult to move the air to the side.

FIG. 1 is a cross-sectional view showing an engine including the cam chain tensioner device according to the embodiment of the present invention. FIG. 2 is a plan view showing a chain tensioner provided on the upper wall of the cylinder block. FIG. 3 is a plan view showing a state in which the cap member is removed from FIG. FIG. 4 is a plan view showing a state in which the gasket is removed from FIG. FIG. 5 is a sectional view taken along line VV of FIG. FIG. 6 is a sectional view taken along line VI-VI of FIG. FIG. 7 is a perspective view showing a cap member. FIG. 8 is a bottom view showing the cap member. FIG. 9 is a cross-sectional view of a cap member of the chain tensioner provided on the cylinder block.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the explanation, the directions such as front / rear / left / right and up / down are the same as the directions with respect to the engine 10 unless otherwise specified. In each figure, the reference numeral FR indicates the front of the engine, the reference numeral UP indicates the upper side of the engine, and the reference numeral LH indicates the left side of the engine.
FIG. 1 is a cross-sectional view showing an engine 10 including the cam chain tensioner device 32 according to the embodiment of the present invention.
The engine 10 includes a crankcase 12 that rotatably houses a crankshaft 11 extending in the left-right direction, and a cylinder portion 13 extending horizontally or substantially horizontally from the front portion of the crankcase 12 to the front.

A chain drive sprocket 15 is attached to the crankshaft 11.
An oil pump 17 is provided on the side wall (not shown) of the crankcase 12, and the crankcase 12 and the cylinder portion 13 are supplied with oil for lubrication from the oil pump 17 to the crankcase 12 and the cylinder portion 13. A supply passage 18 is provided.
The cylinder portion 13 includes a cylinder block 21, a cylinder head 22, and a head cover 23 which are sequentially assembled to the front portion of the crankcase 12.
A camshaft 25 extending in the left-right direction is rotatably supported on the cylinder head 22, and a cam sprocket 26 is attached to one end of the camshaft 25.

The cam sprocket 26 described above is arranged in a cam chain chamber 13a formed in the cylinder portion 13, and a cam chain 27 is hung between the chain drive sprocket 15 and the cam sprocket 26.
In the cam chain 27, the chain tensioner guide 28 is applied to the slack side 27A hanging from the chain drive sprocket 15 to the cam sprocket 26, and the chain guide 29 is applied to the tension side 27B hanging from the cam sprocket 26 to the chain drive sprocket 15. .. The chain tensioner guide 28 is arranged so as to rise forward in the cam chain chamber 13a.

The upper wall 21a of the cylinder block 21 is provided with a chain tensioner 31 that presses the chain tensioner guide 28 to prevent the cam chain 27 from loosening.
The chain tensioner guide 28 and the chain tensioner 31 constitute a cam chain tensioner device 32.
The chain tensioner 31 includes a tensioner base 21b integrally provided on the upper wall 21a of the cylinder block 21, and a cap member 36 attached to the upper end of the tensioner base 21b with a pair of bolts 35 via a gasket 34 (see FIG. 3). And.

FIG. 2 is a plan view showing a chain tensioner 31 provided on the upper wall 21a of the cylinder block 21.
The cap member 36 of the chain tensioner 31 has a bolt insertion hole 36a through which a pair of bolts 35 are passed, a downwardly projecting downward protrusion 36b formed between the pair of bolt insertion holes 36a, and oil serving as an oil passage. It is provided with a groove 36c.
The downward protrusion 36b and the oil groove 36c are formed on the lower surface of the cap member 36.
The downward protruding portion 36b has a circular contour, and a recess 36d is formed in the central portion. The oil groove 36c is inclined so as to gradually extend forward as it is separated from the center side of the downward protrusion 36b in the left-right direction (specifically, to the left).

FIG. 3 is a plan view showing a state in which the cap member 36 is removed from FIG.
A gasket 34 is sandwiched between the tensioner base 21b and the cap member 36 (see FIG. 2).
The gasket 34 has a circular protrusion insertion hole 34a into which the downward protrusion 36b (see FIG. 2) of the cap member 36 is inserted, and a U-shape provided at the rear of the edge of the protrusion insertion hole 34a in the central portion. A central hole 34c is formed, which is composed of a notch 34b having an edge of the above. Further, the gasket 34 is a filter composed of a plurality of small holes 34d formed so as to overlap one end of the oil groove 36c of the cap member 36 (specifically, the left end (one side end 36k (see FIG. 8))). A portion 34e and a pair of bolt insertion holes 34f through which the bolt 35 (see FIG. 2) is passed are provided.

FIG. 4 is a plan view showing a state in which the gasket 34 is removed from FIG.
The upper surface 21c of the tensioner base 21b is provided with a vertical oil passage 21d, a central through hole 21e, an upper groove 21f, a front communication oil passage 21g, and a pair of screw holes 21h.
The vertical oil passage 21d is formed in the tensioner base 21b so as to extend linearly in the vertical direction and opens to the upper surface 21c, and one end portion (specifically, the left end portion) of the oil groove 36c of the cap member 36 (see FIG. 2). It is formed so as to overlap (one side end portion 36k (see FIG. 8)).

The central through hole 21e is a round hole formed in the central portion of the upper surface 21c so as to extend in the vertical direction, and penetrates the tensioner base 21b. The upper groove 21f is formed so as to straddle the central through hole 21e in the front-rear direction, and is composed of a front groove 21j and a rear groove 21k provided before and after the central through hole 21e. The rear groove 21k is arranged so that the other end of the oil groove 36c of the cap member 36 (see FIG. 2) (detailed, the right end (other side end 36r (see FIG. 8)) overlaps). ..
The front communication oil passage 21g is connected to the front end portion of the front groove 21j and extends in the vertical direction to the tensioner base portion 21b. The pair of screw holes 21h are portions into which a pair of bolts 35 (see FIG. 2) are screwed, and one is arranged diagonally forward to the left and the other diagonally to the right rearward with respect to the central through hole 21e. There is.

FIG. 5 is a sectional view taken along line VV of FIG.
The central through hole 21e of the tensioner base 21b has a plunger 41 that is movably fitted to the inner surface 21m of the central through hole 21e and an inner cylinder that is movably fitted to the hollow portion 41a formed in the plunger 41. 42 and are arranged.
The plunger 41 is composed of an end wall 41c provided at the tip end and a peripheral wall 41d extending from the peripheral edge of the end wall 41c, and an opening of a hollow portion 41a at an end of the peripheral wall 41d opposite to the end wall 41c. A portion 41e is provided.
The end wall 41c includes an annular groove 41g formed in an annular shape on the outer peripheral portion of the inner surface 41f thereof.

The peripheral wall 41d includes a small diameter hole 41h, a tapered hole 41j, a large diameter hole 41k, and an end small diameter hole 41m formed in order from the end wall 41c side.
The inner cylinder 42 is movably inserted into the large-diameter hole 41k and the end small-diameter hole 41m formed to have a diameter larger than that of the small-diameter hole 41h. The small diameter hole 41m at the end is formed to have a smaller inner diameter than the large diameter hole 41k.
The tip end portion (end wall 41c) of the plunger 41 projects from the lower end portion 21n of the tensioner base portion 21b to the cam chain chamber 13a. The lower end portion 21n of the tensioner base portion 21b is formed so as to project downward from the inner surface 21p of the upper wall 21a of the cylinder block 21.

The inner cylinder 42 integrally includes a bottom wall 42a and an inner cylinder peripheral wall 42b extending from the peripheral edge of the bottom wall 42a. An oil hole 42c is formed in the bottom wall 42a. A check valve 44 is provided on the lower surface 42d of the bottom wall 42a to allow the oil in the inner cylinder 42 to flow in one direction (the direction in which the oil flows from the inner cylinder 42 into the hollow portion 41a of the plunger 41) by opening and closing the oil hole 42c. Has been done.
The hollow portion 42e formed by the bottom wall 42a of the inner cylinder 42 and the peripheral wall 42b of the inner cylinder has an opening 42f at the upper portion (specifically, the cap member 36 side).

The check valve 44 includes a check ball 45 provided so as to be in close contact with the edge of the oil hole 42c on the lower surface 42d side, and a ball housing 46 arranged in the lower surface recess 42g formed on the lower surface 42d to accommodate the check ball 45. To be equipped with.
The ball housing 46 includes a housing cup portion 46a formed in a cup shape and a flange portion 46b extending radially outward from the peripheral edge portion on the opening side of the housing cup portion 46a, and oil passes through the housing cup portion 46a. There are multiple small holes (not shown).

A compression coil spring 47 is arranged between the plunger 41 and the ball housing 46. The compression coil spring 47 presses the end wall 41c of the plunger 41 against the chain tensioner guide 28 and the end of the inner cylinder 42 on the opening 42f side against the cap member 36 by its elastic force. Reference numeral 48 in the drawing is a contact point between the end wall 41c of the plunger 41 and the chain tensioner guide 28.

The front communication oil passage 21g of the tensioner base 21b has an opening 21q that penetrates the tensioner base 21b up and down and opens to the cam chain chamber 13a on the inner surface 21p of the upper wall 21a of the cylinder block 21. The opening 21q is located in front of and above the contact point 48.
A chain tensioner guide 28 is arranged below the opening 21q. As a result, the oil discharged from the opening 21q falls on the chain tensioner guide 28, and the sliding portion between the cam chain 27, the cam chain 27 and the chain tensioner guide 28, the chain tensioner guide 28 and the plunger. Lubricate the contacts 48, which are the contacts between each of the 41s.

The downward protruding portion 36b of the cap member 36 is provided with an oil supply port 36e that communicates the rear groove 21k and the recess 36d, and a discharge port 36f that communicates the recess 36d and the front groove 21j.
The oil filler port 36e supplies oil from the rear groove 21k into the recess 36d, and the discharge port 36f discharges the oil in the recess 36d to the front groove 21j.
The fuel filler port 36e and the discharge port 36f have a cross section smaller than the cross-sectional area of the front groove 21j and the rear groove 21k.
The oil groove 36c of the cap member 36 is inclined forward when the chain tensioner 31 is viewed from the side (left-right direction of the engine 10 (see FIG. 1)) as shown by a broken line. .. The front end portion (one side end portion 36k) of the oil groove 36c is arranged higher than the other end portion (other side end portion 36r) on the rear side of the oil groove 36c.

The space in which the opening 41e is closed by the inner cylinder 42 in the hollow portion 41a of the plunger 41 is the high pressure chamber 51. Further, the hollow portion 42e of the inner cylinder 42 and the recess 36d of the cap member 36 are low pressure chambers 52 having a lower pressure than the high pressure chamber 51 and serving as an oil supply chamber for supplying oil to the high pressure chamber 51.
Further, the rear groove 21k, the fuel filler port 36e, the low pressure chamber 52, the discharge port 36f, the front groove 21j and the front communication oil passage 21g constitute the communication oil passage 54, and the discharge port 36f, the front groove 21j and the front groove 21j The front communication oil passage 21g constitutes a low pressure chamber communication passage 54A from the low pressure chamber 52 to the cam chain chamber 13a.

FIG. 6 is a sectional view taken along line VI-VI of FIG.
As shown in FIG. 1, the oil supply passage 18 includes a case oil passage 18a, a block lower oil passage 18b, and a block horizontal oil passage 18c as oil passages communicating with each other.
The case oil passage 18a is formed in the crankcase 12 so as to extend from the oil pump 17 to the cylinder block 21. The block lower oil passage 18b is formed in the cylinder block 21 in the vicinity of the mating portion of the cylinder block 21 along the mating portion with the crankcase 12.
The block horizontal oil passage 18c is formed so as to extend in the front-rear direction in the upper wall 21a of the cylinder block 21. The oil supply passage 18 extends from the block horizontal oil passage 18c to the cylinder head 22 and lubricates each part of the cylinder head 22.

As shown in FIG. 6, a vertical oil passage 21d extending upward branches from the middle of the block horizontal oil passage 18c. The opening 21r that opens to the upper surface 21c in the vertical oil passage 21d communicates with the end portion (one side end portion 36k (see FIG. 8)) of the oil groove 36c of the cap member 36 via the filter portion 34e of the gasket 34. There is.
Therefore, when the oil flowing in the oil supply passage 18 from the oil pump 17 (see FIG. 1) side contains contaminants such as dust and abrasion powder, the oil contaminants flowing in the vertical oil passage 21d are gaskets. It is collected by the filter unit 34e of 34 and collected on the lower surface of the filter unit 34e.

When the engine 10 (see FIG. 1) is stopped in this state, the oil flow in the vertical oil passage 21d is stopped together with the oil supply passage 18, so that the contaminants accumulated on the lower surface of the filter portion 34e are inside the vertical oil passage 21d. And fall into the block horizontal oil passage 18c. Then, when the engine is restarted, the contaminants in the block horizontal oil passage 18c move to the downstream side together with the oil, and are finally collected by an oil filter (not shown) provided in the lower part of the engine 10. By providing the filter portion 34e in the chain tensioner 31 in this way, it is possible to prevent oil contaminants from flowing into the high pressure chamber 51.

FIG. 7 is a perspective view showing the cap member 36, and FIG. 8 is a bottom view showing the cap member 36. FIG. 9 is a cross-sectional view of the cap member 36 of the chain tensioner 31 provided on the cylinder block 21, and shows a cross section cut at the position of the IX-IX line in FIG.
As shown in FIGS. 7 to 9, the lower surface 36 g of the cap member 36 has a downward projecting portion 36b protruding in a tubular shape and an oil groove 36c located on one side (left side) of the downward projecting portion 36b. A pair of bolt insertion holes 36a are formed and penetrate the cap member 36 up and down.
The downward projecting portion 36b is formed so that an oil supply port 36e and a discharge port 36f penetrating the outer peripheral surface 36h and the inner peripheral surface 36j respectively extend back and forth. The inner peripheral surface 36j is also the inner peripheral surface of the recess 36d.

The refueling port 36e and the discharge port 36f have the same axis 56. That is, the fuel filler port 36e and the discharge port 36f are formed coaxially. As a result, the man-hours required for processing the fuel filler port 36e and the discharge port 36f can be reduced, and workability can be improved.
The oil groove 36c has the same width as the circular one-side end 36k, which is the end on one side (left side), and the one-side end 36k, which gradually narrows in width and then extends to the rear of the discharge port 36f with a constant width. It consists of a part 36m. The depth from the lower surface 36g to the bottom surface 36n of the oil groove 36c is constant.
The equal width portion 36m has a straight groove 36p extending linearly from one side end portion 36k and a curve extending from the end portion of the straight groove 36p along the outer peripheral surface 36h of the downward protruding portion 36b in the vicinity of the downward protruding portion 36b. It consists of a groove 36q.
The straight groove 36p extends along a straight line 57 passing through the center of each of the pair of bolt insertion holes 36a. The curved groove 36q is provided with the other side end portion 36r, which is the other side (right side) end portion.

The operation of the chain tensioner 31 described above will be described below.
In FIG. 1, when the engine 10 is started, the oil pump 17 operates, and the oil stored in the lower part of the engine 10 is supplied by the oil pump 17 to each part of the crankcase 12 and the cylinder part 13 through the oil supply passage 18. Will be done.
In FIG. 6, the oil supplied to the block horizontal oil passage 18c of the oil supply passage 18 branches and flows into the vertical oil passage 21d of the chain tensioner 31, is filtered by the filter portion 34e of the gasket 34, and contains contaminants in the oil. Is excluded.

The oil that has passed through the filter portion 34e flows through the oil groove 36c and reaches the rear groove 21k in FIG.
In FIG. 5, the oil is supplied from the rear groove 21k through the fuel filler port 36e to the low pressure chamber 52. In the low pressure chamber 52, the pressure is increased by the oil supplied from the oil filler port 36e, so that the check ball 45 of the check valve 44 is separated from the edge of the oil hole 42c, and the oil in the low pressure chamber 52 is pressurized through the oil hole 42c. It flows into the room 51.

As a result, the pressure in the high pressure chamber 51 gradually increases, so that the plunger 41 descends and presses the cam chain 27 via the chain tensioner guide 28.
At this time, when the plunger 41 is pushed back by the movement of the cam chain 27 and the volume in the high pressure chamber 51 is reduced, a part of the oil in the high pressure chamber 51 passes through the gap between the plunger 41 and the inner cylinder 42. Further, the oil flows out to the cam chain chamber 13a through the gap between the plunger 41 and the central through hole 21e.

Further, the excess oil supplied from the oil filler port 36e to the low pressure chamber 52 is discharged from the low pressure chamber 52 to the front groove 21j through the discharge port 36f. Then, the oil flows out from the front groove 21j through the front communication oil passage 21g to the cam chain chamber 13a.
For example, in FIG. 6, when air is mixed in the oil flowing into the vertical oil passage 21d from the block horizontal oil passage 18c, the air is supplied to the filter portion 34e, the oil groove 36c shown in FIG. 5, the rear groove 21k, and refueling. It is discharged to the cam chain chamber 13a through the port 36e, the low pressure chamber 52, and the low pressure chamber communication passage 54A (that is, the discharge port 36f, the front groove 21j, and the front communication oil passage 21g).

Further, for example, even if air is accumulated in a high portion (longitudinal oil passage 21d, oil groove 36c, rear groove 21k, upper portion of recess 36d, etc.) in the above oil passage, this Since air does not easily flow to the high pressure chamber 51 arranged in the lower portion of the chain tensioner 31, air mixing into the oil in the high pressure chamber 51 is suppressed, and a good pressing force for pressing the cam chain 27 is ensured. Can be done.

As shown in FIGS. 1 and 5 above, the cam chain tensioner device 32 includes a chain tensioner guide 28 and a chain tensioner 31.
The chain tensioner guide 28 slides on the cam chain 27 that transmits the rotational force of the crankshaft 11 of the engine 10 to the camshaft 25. The chain tensioner 31 hydraulically presses the chain tensioner guide 28.
The chain tensioner 31 includes a high pressure chamber 51, a low pressure chamber 52, and a low pressure chamber connecting passage 54A.

The high pressure chamber 51 generates a pressing force on the plunger 41 as a pressing member that presses the chain tensioner guide 28. The low pressure chamber 52 as the oil supply chamber supplies oil to the high pressure chamber 51. The low-pressure chamber communication passage 54A as a communication passage communicates from the low-pressure chamber 52 to the inside of the engine 10 (specifically, the cam chain chamber 13a).
According to this configuration, by providing the low pressure chamber connecting passage 54A in the low pressure chamber 52, air can be bleeded from the low pressure chamber 52, air can be suppressed from being mixed into the high pressure chamber 51, and air can be bleeded efficiently. It can be performed.

Further, as shown in FIG. 5, the low pressure chamber communication passage 54A has an opening 21q that opens toward the chain tensioner guide 28.
According to this configuration, the oil discharged from the opening 21q of the low pressure chamber communication passage 54A is supplied to the chain tensioner guide 28, whereby the cam chain 27 can be refueled via the chain tensioner guide 28.

Further, the opening 21q is located above the contact point 48 between the chain tensioner guide 28 and the chain tensioner 31.
According to this configuration, the oil discharged from the opening 21q can be supplied to the contact 48, and the wear of the contact 48 can be suppressed.

Further, as shown in FIGS. 3, 5 and 6, the chain tensioner 31 has a filter unit 34e as a filter provided on the upstream side of the low pressure chamber 52 for filtering oil, and the filter unit 34e Is composed of a gasket 34 provided in the chain tensioner 31.
According to this configuration, since the filter portion 34e is formed by using the gasket 34, the number of parts can be reduced.

As shown in FIGS. 1 and 6, the chain tensioner 31 is provided on the upper surface of the cylinder portion 13 extending horizontally from the crankcase 12 of the engine 10. The chain tensioner 31 is provided with a vertical oil passage 21d as an oil supply passage that branches from the block horizontal oil passage 18c as a horizontally extending horizontal oil passage used for oil supply to parts other than the chain tensioner 31 and extends to the filter portion 34e. Has been done. Examples of parts other than the chain tensioner 31 described above include a valve operating mechanism provided in the cylinder head 22.
The vertical oil passage 21d is formed in a straight line and connects the filter portion 34e and the block horizontal oil passage 18c.

According to this configuration, the contaminants in the oil that flow from the block horizontal oil passage 18c side and collect in the filter unit 34e separate from the filter unit 34e when the oil flow stops due to an engine stop or the like. Then, when the engine is restarted, the contaminants flow through the block horizontal oil passage 18c. Therefore, the number of times the filter portion 34e is cleaned can be reduced, and the maintainability of the chain tensioner 31 can be improved.

Further, as shown in FIGS. 5 and 8, the refueling port 36e for supplying oil to the low pressure chamber 52 and the discharge port 36f connected from the low pressure chamber 52 to the low pressure chamber communication passage 54A are on the same axis as the same member. It is provided.
According to this configuration, it is possible to reduce the number of parts and improve workability.

Further, as shown in FIG. 5, the discharge port 36f is arranged higher than the fuel filler port 36e.
According to this configuration, air can be easily discharged from the low pressure chamber 52 through the discharge port 36f.
Further, as shown in FIGS. 5 and 9, in the oil groove 36c as an oil passage connecting the filter portion 34e and the oil filler port 36e side, one side end portion 36k facing the filter portion 34e is the other side end portion. It is placed higher than 36r.
According to this configuration, it is possible to make it difficult for air to move from the filter portion 34e side to the low pressure chamber 52 side through the oil groove 36c, so that it is possible to further suppress air mixing into the oil in the high pressure chamber 51.

The above-described embodiment shows only one aspect of the present invention, and can be arbitrarily modified and applied without departing from the gist of the present invention.
The present invention can be applied to engines of various vehicles, industrial machines and the like.

10 Engine 11 Crankshaft 12 Crankcase 13 Cylinder 18c Block Horizontal oil passage (horizontal oil passage)
21d Vertical oil passage (fuel supply passage)
21q Opening 25 Camshaft 27 Camchain 28 Chain tensioner guide 31 Chain tensioner 34e Filter part (filter)
36c oil groove (oil passage)
36e Refueling hole (refueling channel)
36f discharge hole (discharge path)
36k One side end 36r Other side end 41 Plunger (pressing member)
48 contacts 51 high pressure chamber 52 low pressure chamber (oil supply chamber)
54A low pressure chamber communication passage (communication passage)

Claims

The chain tensioner guide (28) that slides with the cam chain (27) that transmits the rotational force of the crankshaft (11) of the engine (10) to the camshaft (25) and the chain tensioner guide (28) are hydraulically driven. In a cam chain tensioner device including a chain tensioner (31) for pressing,
The chain tensioner (31) includes a high-pressure chamber (51) that generates a pressing force on a pressing member (41) that presses the chain tensioner guide (28), and an oil supply chamber that supplies oil to the high-pressure chamber (51). A cam chain tensioner device including (52) and a communication passage (54A) communicating from the oil supply chamber (52) into the engine (10).
The cam chain tensioner device according to claim 1, wherein the communication passage (54A) has an opening (21q) that opens toward the chain tensioner guide (28).
The cam chain tensioner device according to claim 2, wherein the opening (21q) is located above a contact point (48) between the chain tensioner guide (28) and the chain tensioner (31).
The chain tensioner (31) has a filter (34e) provided on the upstream side of the oil supply chamber (52) for filtering oil, and the filter (34e) is attached to the chain tensioner (31). The cam chain tensioner device according to any one of claims 1 to 3, further comprising a gasket (34).
The chain tensioner (31) is provided on the upper surface of a cylinder portion (13) extending horizontally from the crankcase (12) of the engine (10), and is horizontally used for oil supply to parts other than the chain tensioner (31). An oil supply passage (21d) that branches from the horizontal oil passage (18c) extending in the direction and extends to the filter (34e) is provided, and the oil supply passage (21d) is formed in a straight line with the filter (34e) and the filter. The cam chain tensioner device according to claim 4, wherein the cam chain tensioner device is connected to a horizontal oil passage (18c).
The oil supply port (36e) for supplying oil to the oil supply chamber (52) and the discharge port (36f) connected from the oil supply chamber (52) to the communication passage (54A) are provided coaxially with the same member. The cam chain tensioner device according to claim 5, wherein the cam chain tensioner device is provided.
The cam chain tensioner device according to claim 6, wherein the discharge port (36f) is arranged higher than the fuel filler port (36e).
In the oil passage (36c) connecting the filter (34e) and the oil filler port (36e) side, one side end (36k) facing the filter (34e) is higher than the other side end (36r). The cam chain tensioner device according to claim 7, wherein the cam chain tensioner device is arranged.