JP4260189B2 - Hydraulic tensioner - Google Patents

Description

  The present invention relates to a hydraulic tensioner for applying appropriate tension to, for example, a timing belt of a vehicle engine or a timing chain.

  Hydraulics equipped with a check valve mechanism for maintaining proper tension in the timing belt and timing chain that transmit rotation between the crankshaft and camshaft of the vehicle engine and suppressing vibrations generated during the running A type tensioner is widely used.

Conventionally, a hydraulic tensioner 500 having such a check valve mechanism includes a plunger 520 that slidably protrudes from a plunger receiving hole 511 of a housing body 510 toward a traveling chain, as shown in FIGS. A plunger biasing spring 530 that is housed in a high-pressure oil chamber R formed between the plunger housing hole 511 and the plunger 520 and biases the plunger 520 in a projecting direction, and a bottom portion of the plunger housing hole 511. And a check valve unit 540 that is incorporated by press-fitting and prevents reverse flow of the pressure oil in the high-pressure oil chamber R.
The check valve unit 540 includes a check ball valve 541 that regulates the flow of pressure oil, a ball guide 542 made of synthetic resin that floats the check ball valve 541 in an enclosed state, and the high pressure oil chamber side of the ball guide 542. A disk-shaped retainer 543 that is fixed by caulking in the entire outer peripheral region and seals the check ball valve 541 in the ball guide 542 and a ball seat 544 that prevents backflow of pressure oil by the seating of the check ball valve 541. The synthetic resin ball guide 542 is provided with an outer peripheral tongue piece 542b that is press-fitted and fixed to the bottom of the plunger receiving hole 511, and the synthetic resin ball guide 542 has a whole outer peripheral area on the high pressure oil chamber side. And a disc-shaped retainer 543 are formed with a caulking spring positioning mounting recess 543b and a caulking portion 542a. It is. (For example, refer to Patent Document 1).
Japanese Patent No. 3841355 (Claims, FIG. 2)

However, in the conventional hydraulic tensioner 500 as described above, since the ball guide 542 is made of synthetic resin, the ball guide 542 is elastically deformed due to the high pressure in the high-pressure oil chamber R, and the oil temperature in the engine room. Expansion and contraction may occur with changes.
As a result, the performance of the check valve unit varied due to subtle dynamic dimensional changes of the ball guide due to the operating conditions of the engine room. Therefore, further improvements were made to demonstrate more stable performance. It was necessary to apply.

  Therefore, the present invention solves the conventional problems, that is, the object of the present invention is that the check valve unit elastically deforms and expands and contracts due to the high pressure in the high pressure oil chamber and the high temperature change of the oil in the engine room. Accordingly, it is an object of the present invention to provide a hydraulic tensioner that stably exhibits a check valve function and prevents wear damage of a ball guide and a plunger receiving hole.

  According to a first aspect of the present invention, there is provided a plunger which is accommodated in a high pressure oil chamber formed between a plunger protruding slidably from the plunger receiving hole of the housing body toward the traveling chain and the plunger receiving hole and the plunger. A hydraulic tensioner comprising a plunger biasing spring biasing in the protruding direction of the valve and a check valve unit incorporated in the bottom of the plunger receiving hole to prevent backflow of pressure oil in the high pressure oil chamber. A valve unit is mounted on the high pressure oil chamber side of a ball guide made of steel and a check ball valve that regulates the flow of pressure oil, an inner peripheral wall that allows the check ball valve to float in an enclosed state, and the ball guide Steel retainer with pressure oil communication hole for supplying pressure oil to the high pressure oil chamber side with the check ball valve sealed inside, and supply of pressure oil to the ball guide The ball guide is press-fitted and fixed to the inner peripheral wall of the plunger receiving hole with the steel ball seat that prevents the backflow of pressure oil by sitting on the check ball valve and the ball seat in close contact with the bottom of the plunger receiving hole A stopper ring made of synthetic resin, and the stopper ring is fitted and fixed to a ring mounting step portion formed by reducing the diameter of the outer peripheral wall of the ball guide on the high pressure oil chamber side. By providing an end portion and an annular elastic tongue piece that extends from the base end portion of the ring and abuts against the inner peripheral wall of the plunger receiving hole, the above-described problem is solved.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the annular elastic tongue piece has a tapered contact surface whose diameter decreases from the high pressure oil chamber side toward the pressure oil supply side. Thus, the above-described problems are further solved.

  According to a third aspect of the present invention, in addition to the structure of the first or second aspect, a ring locking convex portion for locking the ring base end portion of the stopper ring is provided on the outer peripheral wall of the ball guide. By providing the projection, the above-described problems are further solved.

  According to a fourth aspect of the present invention, in addition to the structure according to any one of the first to third aspects, the retainer is recessed in the high pressure oil chamber side of the ball guide so as to extend in the longitudinal direction of the plunger. The above-described problems are further solved by being press-fitted into a retainer-receiving recess having a vertical inner peripheral wall extending along the wall.

  According to a fifth aspect of the present invention, in addition to the configuration according to any one of the first to fourth aspects, the ball seat is formed in a concave portion for seat accommodation that is recessed on the pressure oil supply side of the ball guide. The above-described problems are further solved by press fitting.

  Accordingly, the present invention provides a plunger protruding slidably from the plunger receiving hole of the housing body toward the traveling chain, and a high pressure oil chamber formed between the plunger receiving hole and the plunger, and the protruding direction of the plunger A timing belt for a vehicular engine, comprising a plunger biasing spring that biases the valve and a check valve unit that is incorporated in the bottom of the plunger housing hole and prevents the backflow of pressure oil in the high pressure oil chamber, Not only can appropriate tension be applied to the timing chain and the like, but also the following specific effects can be achieved.

According to the hydraulic tensioner of the present invention according to claim 1, the check valve unit includes a check ball valve that regulates the flow of pressure oil, and a steel ball including an inner peripheral wall that allows the check ball valve to float in an enclosed state. Steel retainer and ball guide provided with a pressure oil communication hole that is attached to the high pressure oil chamber side of the guide and the ball guide and allows the pressure oil to flow to the high pressure oil chamber side with the check ball valve sealed in the ball guide The ball guide is inserted into the plunger receiving hole with the steel ball seat and the ball seat in close contact with the bottom of the plunger receiving hole. Since it is composed of a stopper ring made of synthetic resin that is press-fitted to the peripheral wall, the steel ball guide has higher hardness and lower linear expansion coefficient than synthetic resin, By suppressing the expansion and contraction due to temperature changes of the oil of the elastic deformation and the engine room due to the high pressure oil chamber, a check valve unit can exhibit a stable check valve functions.
The stopper ring extends from the ring base end and the ring base end to be fixed to the ring mounting step formed by reducing the diameter of the outer peripheral wall of the ball guide on the high pressure oil chamber side. Since the annular elastic tongue piece that abuts against the inner peripheral wall prevents contact between the outer peripheral wall of the ball guide and the inner peripheral wall of the plunger receiving hole, the outer peripheral wall of the ball guide and the inner peripheral wall of the plunger receiving hole are Wear damage can be prevented.
The check valve unit can be simply fitted on the ring mounting step of the ball guide without complicated processing such as providing an outer peripheral tongue piece on the ball guide as in the conventional hydraulic tensioner. Can be press-fitted and fixed to the inner peripheral wall of the plunger accommodation hole, so that the check valve unit can be assembled easily.

  According to the hydraulic tensioner of the present invention according to claim 2, in addition to the effect of the hydraulic tensioner according to claim 1, the annular elastic tongue piece is reduced in diameter from the high pressure oil chamber side toward the pressure oil supply side. Because of the tapered contact surface, when the check valve unit is assembled to the plunger receiving hole, the annular elastic tongue made of synthetic resin is elastically deformed corresponding to the inner peripheral wall of the plunger receiving hole. The check valve unit can be easily inserted into the plunger receiving hole, and after the check valve unit is assembled into the plunger receiving hole, the annular elastic tongue piece exerts a wedge effect on the plunger receiving hole. Therefore, the check valve unit can be securely fixed to the bottom of the plunger accommodation hole.

  According to the hydraulic tensioner of the present invention according to claim 3, in addition to the effect exerted by the hydraulic tensioner according to claim 1 or 2, the ring locking projection for locking the ring base end portion of the stopper ring. When the check valve unit is assembled to the plunger receiving hole, the ball of the stopper ring that tends to be generated due to contact with the inner peripheral wall of the plunger receiving hole Since the displacement with respect to the guide is prevented, the ball guide can be simply and surely press-fitted and fixed to the inner peripheral wall of the plunger receiving hole.

According to the hydraulic tensioner of the present invention according to claim 4, in addition to the effect exhibited by the hydraulic tensioner according to any one of claims 1 to 3, the retainer is recessed in the high pressure oil chamber side of the ball guide. Since the ball guide and the retainer can be handled as a single unit by being press-fitted into the recessed recess for retaining the retainer, the retainer is removed when the check valve unit is assembled to the bottom of the plunger receiving hole. Without making it possible, the check valve unit can be easily and firmly assembled.
In addition, since the retainer-receiving recess has a vertical inner peripheral wall extending in the longitudinal direction of the plunger, a spring positioning mounting recess by caulking is formed on the inner peripheral wall of the synthetic resin ball guide as in the conventional hydraulic tensioner. Compared to the case, the plunger urging spring having a larger diameter can be stably disposed on the retainer, so that it is possible to further increase the load of the plunger urging spring.

  According to the hydraulic tensioner of the present invention according to claim 5, in addition to the effect exhibited by the hydraulic tensioner according to any one of claims 1 to 4, the ball seat is disposed on the pressure oil supply side of the ball guide. Since the ball guide and the ball seat can be handled as a single unit by being press-fitted into the recessed portion for seat accommodation, when assembling the check valve unit at the bottom of the plunger accommodation hole, The check valve unit can be easily and firmly assembled without dropping the ball seat.

  The present invention includes a plunger that slidably protrudes from a plunger accommodation hole of the housing body toward the traveling chain, and a high-pressure oil chamber formed between the plunger accommodation hole and the plunger, and is attached to the direction in which the plunger projects. A hydraulic tensioner comprising a plunger biasing spring that biases and a check valve unit that is incorporated in the bottom of the plunger receiving hole and prevents the backflow of pressure oil in the high-pressure oil chamber. A check ball valve for regulating oil flow, a steel ball guide having an inner peripheral wall for allowing the check ball valve to float in an enclosed state, and a check ball valve mounted on the high pressure oil chamber side of the ball guide. A steel retainer having a pressure oil communication hole that allows pressure oil to flow to the high pressure oil chamber side in a sealed state and a pressure oil supply side of the ball guide A steel ball seat that prevents backflow of pressure oil by seating the check ball valve, and a synthetic resin that press-fits and fixes the ball guide to the inner peripheral wall of the plunger housing hole in a state where the ball seat is in close contact with the bottom of the plunger housing hole A ring base end portion that is externally fixed to a ring mounting step portion formed by reducing the diameter of the outer peripheral wall of the ball guide on the high-pressure oil chamber side, and the ring base. And an annular elastic tongue that extends from the end and contacts the inner peripheral wall of the plunger receiving hole. As long as the check valve function is stably exhibited and the wear damage of the ball guide and the plunger receiving hole is prevented, the specific embodiment thereof is May no even what made things.

  For example, a plunger that protrudes slidably from the plunger accommodation hole of the housing body toward the traveling chain, and a high-pressure oil chamber formed between the plunger accommodation hole and the plunger and biased in the direction in which the plunger projects. And a check valve unit that is incorporated into the bottom of the plunger housing hole by press-fitting and prevents backflow of the pressure oil in the high-pressure oil chamber, and the pressure oil is present in the high-pressure oil chamber. A hydraulic tensioner, or such a hydraulic tensioner or spring tensioner may be added with a rack formed on the plunger and a ratchet mechanism pivotally supported by the housing body.

  In addition, the specific material of the ball guide incorporated in the hydraulic tensioner of the present invention may be any steel material, aluminum, etc., as long as it has high hardness and low linear expansion coefficient. In that case, the elastic deformation caused by the high pressure in the high pressure oil chamber and the expansion and contraction caused by the temperature change of the oil in the engine room can be suppressed, and further stabilization of the check valve function of the check valve unit can be expected. More preferred.

  In addition, as for a specific aspect of the ring locking convex portion provided on the outer peripheral wall of the ball guide incorporated in the hydraulic tensioner of the present invention, as long as the stopper ring can be locked, the outer periphery of the ball guide Any of an annular shape protruding on the wall and a plurality of convex shapes formed on the outer peripheral wall of the ball guide may be used.

  The specific material of the stopper ring incorporated in the hydraulic tensioner of the present invention may be any of synthetic resin, rubber, etc. as long as it has heat resistance. In this case, it is more preferable because it can be expected to further stabilize the check valve function of the check valve unit by suppressing expansion and contraction due to the temperature change of the oil in the engine room.

Hereinafter, a hydraulic tensioner 100 according to an embodiment of the present invention will be described with reference to the drawings.
Here, FIG. 1 is a usage pattern diagram using a hydraulic tensioner according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the hydraulic tensioner shown in FIG. 1, and FIG. 4 is a partially cutaway and enlarged perspective view of the check valve unit shown in FIG. 4, FIG. 4 is a plan view of the check valve unit shown in FIG. 2, and FIG. 5 is a check view shown in FIG. FIG. 6 is a cross-sectional view of the valve unit, and FIG. 6 is a plan view of the check valve unit shown in FIG. 2 as viewed from below.

First, as shown in FIG. 1, a hydraulic tensioner 100 according to this embodiment is provided between a driving side sprocket S1 rotated by an engine crankshaft and a driven side sprocket S2, S2 fixed to a camshaft. It is attached to the engine body on the slack side of the timing chain C that is being stretched, and the plunger 120 protrudes from the front surface of the housing body 110 so as to be able to protrude and retract, and the plunger 120 is swingably supported on the engine body side. Tension is applied to the slack side of the timing chain C via the movable lever L1 by pressing the back surface near the swing end of the movable lever L1.
A fixed guide L2 for guiding the travel of the timing chain C is attached to the tension body side of the timing chain C on the engine body side.

  The driving side sprocket S1 and the driven side sprocket S2 described above are configured such that when the driving side sprocket S1 rotates in the direction of the arrow, the timing chain C travels in the direction of the arrow. The drive side sprocket S2 rotates in the direction of the arrow, and the rotation of the drive side sprocket S1 is transmitted to the driven side sprocket S2.

As shown in FIG. 2, the hydraulic tensioner 100 according to the present embodiment has an outer cylindrical plunger 120 slidably inserted into a plunger receiving hole 111 formed in the housing main body 110. In the high-pressure oil chamber R formed between the plunger housing hole 111, a plunger biasing spring 130 made of a coil spring that biases the plunger 120 in the protruding direction is housed.
Further, a check valve unit 140 for preventing the backflow of the pressure oil inside the high pressure oil chamber R is incorporated into the bottom of the plunger housing hole 111 described above by press-fitting and fixing.

2 is a rack formed on the plunger 120, and 150 is a ratchet pawl supported on the housing main body 110.
The ratchet pawl body 150 and the rack 121 of the plunger 120 mesh with each other so that the plunger 120 is prevented from moving backward.
2 is a ratchet urging spring for urging the ratchet pawl 150 toward the rack 121 of the plunger 120, and P is a pressure opening at the bottom of the plunger receiving hole 111. This is an oil supply path.

Therefore, a specific form of the check valve unit 140, which is the most characteristic of the hydraulic tensioner 100 of this embodiment, will be described in detail with reference to FIGS.
First, as shown in FIG. 3 to FIG. 6, the check valve unit 140 is made of steel having a check ball valve 141 that regulates the flow of pressure oil and an inner peripheral wall that allows the check ball valve 141 to float in an enclosed state. The ball guide 142 and a pressure oil communication hole 143a that is attached to the high pressure oil chamber side of the ball guide 142 and allows the pressure oil to flow to the high pressure oil chamber side with the check ball valve 141 sealed inside the ball guide 142. A steel retainer 143 provided with the ball guide 142, a steel ball seat 144 which is attached to the pressure oil supply side of the ball guide 142 and prevents the backflow of the pressure oil by the seating of the check ball valve 141, and the ball seat 144 as a plunger A synthetic resin stopper that press-fits and fixes the ball guide 142 to the inner peripheral wall of the plunger receiving hole 111 in close contact with the bottom of the receiving hole 111. It is composed of a grayed 145.

As shown in FIGS. 3 to 6, a retainer accommodating recess 142 a having a vertical inner peripheral wall 142 a ′ extending along the longitudinal direction of the plunger 120 is provided on the high pressure oil chamber side of the ball guide 142. A retainer 143 is press-fitted into the housing recess 142a.
Further, as shown in FIGS. 3 to 6, a sheet accommodating recess 142b is provided on the pressure oil supply side of the ball guide 142, and a ball sheet 144 is press-fitted into the sheet accommodating recess 142b. Yes.
A ring mounting step 142c having a smaller diameter than the other outer peripheral wall portion is formed on the outer peripheral wall of the ball guide 142 on the high pressure oil chamber side.

As shown in FIGS. 3 to 5, the stopper ring 145 includes a ring base end portion 145a that is externally fixed to the ring mounting step 142c of the ball guide 142, and extends from the ring base end portion 145a. And an annular elastic tongue piece 145b that abuts against the inner peripheral wall of the plunger receiving hole 111.
The annular elastic tongue piece 145b has a tapered contact surface 145b ′ that is reduced in diameter from the high pressure oil chamber side toward the pressure oil supply side.

In the hydraulic tensioner 100 of this embodiment obtained in this way, the ball guide 142 is made of steel.
Therefore, the steel ball guide 142 has a higher hardness and a lower linear expansion coefficient than those made of synthetic resin, resulting in elastic deformation caused by the high pressure inside the high pressure oil chamber R and the temperature change of the oil in the engine room. Therefore, the check valve unit 140 can exhibit a stable check valve function.

Further, a stopper ring 145 includes a ring base end portion 145a that is externally fixed to a ring mounting step 142c formed by reducing the outer peripheral wall of the ball guide 142 on the high pressure oil chamber side, and the ring base end portion 145a. An annular elastic tongue piece 145 b that extends and contacts the inner peripheral wall of the plunger receiving hole 111 is provided.
Therefore, since the contact between the outer peripheral wall of the ball guide 142 and the inner peripheral wall of the plunger receiving hole 111 is prevented, it is possible to prevent the outer peripheral wall of the ball guide 142 and the inner peripheral wall of the plunger receiving hole 111 from being damaged by wear.
Then, the stopper ring 145 is merely fitted on the ring mounting step 142c of the ball guide 142 without performing complicated processing such as providing the outer peripheral tongue piece 542b on the ball guide 542 as in the conventional hydraulic tensioner 500. Thus, since the check valve unit 140 can be press-fitted and fixed to the inner peripheral wall of the plunger accommodation hole 111, the assembly work of the check valve unit 140 can be easily achieved.

  The annular elastic tongue 145b has a tapered contact surface 145b ′ whose diameter decreases from the high pressure oil chamber side toward the pressure oil supply side, so that the check valve unit 140 is assembled in the plunger receiving hole 111. In this case, since the annular elastic tongue 145b made of synthetic resin is elastically deformed corresponding to the inner peripheral wall of the plunger receiving hole 111, the check valve unit 140 can be easily inserted into the plunger receiving hole 111. After the check valve unit 140 is assembled into the plunger receiving hole 111, the annular elastic tongue 145b exerts a wedge effect on the plunger receiving hole 111, so that the check valve unit 140 is placed at the bottom of the plunger receiving hole 111. It can be fixed securely.

The retainer 143 is press-fitted into a retainer-accommodating recess 142 a that is recessed on the high pressure oil chamber side of the ball guide 142.
Accordingly, since the ball guide 142 and the retainer 143 can be handled as a single unit, the check valve unit 140 can be handled without dropping the retainer 143 when the check valve unit 140 is assembled to the bottom of the plunger receiving hole 111. Can be assembled easily and firmly.

The retainer-accommodating concave portion 142 a includes a vertical inner peripheral wall 142 a ′ that extends along the longitudinal direction of the plunger 120.
Therefore, when the caulking portion 542a as the fixing means of the retainer 543 is formed on the inner peripheral wall of the ball guide 542 as in the conventional hydraulic tensioner 500, that is, a part of the inner peripheral wall of the synthetic resin ball guide 542 by caulking. Since the plunger biasing spring 130 having a larger diameter can be stably disposed on the retainer 143 as compared with the case where the plunger is overhanged on the peripheral edge of the retainer 543, the plunger biasing spring 130 Further increase in load is possible.

In addition, the ball seat 144 is press-fitted into a seat accommodating recess 142 b that is recessed on the pressure oil supply side of the ball guide 142.
Therefore, since the ball guide 142 and the ball seat 144 can be handled as a single body, the check valve unit 140 is not dropped when the check valve unit 140 is assembled to the bottom of the plunger receiving hole 111 without dropping the ball seat 144. The effect is enormous, for example, the unit 140 can be easily and firmly assembled.

Next, a modification of the hydraulic tensioner 100 of the present invention is shown in FIG.
Here, in the hydraulic tensioner 200 which is a modification of the present invention, the configuration other than the ring locking convex portion 242d of the ball guide 242 is exactly the same as that of the hydraulic tensioner 100 described above. 1 and FIG. 6 are replaced with reference numerals of the 200 series, and the description of the configuration of the ball guide 242 other than the ring locking convex part 242d is omitted.

Accordingly, the ring locking convex portion 242d of the ball guide 242 that is the most characteristic of the hydraulic tensioner 200 which is a modification of the present invention will be described.
That is, as shown in FIG. 7, a ring locking convex portion 242 d that locks the ring base end portion 245 a of the stopper ring 245 is provided on the outer peripheral wall of the ball guide 242.
The ring locking convex portion 242d has a tapered surface 242d ′ whose diameter increases from the high pressure oil chamber side toward the pressure oil supply side.

In the hydraulic tensioner 200 which is a modified example of the present invention obtained as described above, the ring locking convex portion 242d for locking the ring base end portion 245a of the stopper ring 245 protrudes from the outer peripheral wall of the ball guide 242. It is installed.
Therefore, the hydraulic tensioner 200 which is a modification of the present invention has an inner peripheral wall of the plunger accommodation hole 211 when the check valve unit 240 is assembled to the plunger accommodation hole 211 in addition to the effect exhibited by the hydraulic tensioner 100 described above. Since the positional deviation of the stopper ring 245 that tends to occur due to contact with the ball guide 242 is prevented, the ball guide 242 can be simply and surely press-fitted and fixed to the inner peripheral wall of the plunger receiving hole 211.

Further, the ring locking convex portion 242d has a tapered surface 242d ′ whose diameter increases from the high pressure oil chamber side toward the pressure oil supply side.
Therefore, when the stopper ring 245 is assembled to the outer peripheral wall of the ball guide 242, the ring base end portion 245a of the stopper ring 245 made of synthetic resin is elastically deformed corresponding to the tapered surface 242d 'of the ring locking convex portion 242d. Therefore, the effect is enormous, for example, the stopper ring 245 can be easily assembled to the outer peripheral wall of the ball guide 242.

FIG. 3 is a diagram showing how the hydraulic tensioner according to one embodiment of the present invention is used. Sectional drawing of the hydraulic tensioner shown in FIG. FIG. 3 is a perspective view in which the check valve unit shown in FIG. 2 is partially broken and enlarged. The top view which looked at the non-return valve unit shown in FIG. 2 from upper direction. Sectional drawing of the non-return valve unit shown in FIG. The top view which looked at the non-return valve unit shown in FIG. 2 from the downward direction. Sectional drawing of the hydraulic tensioner which is a modification of this invention. Sectional drawing of the conventional hydraulic tensioner. The perspective view of the non-return valve unit integrated in the conventional hydraulic tensioner.

Explanation of symbols

100, 200, 500 ... Hydraulic tensioner 110, 210, 510 ... Housing body 111, 211, 511 ... Plunger receiving hole 120, 220, 520 ... Plunger 121, 221 ... Rack 130, 230, 530 ... Plunger biasing springs 140, 240, 540 ... Check valve units 141, 241, 541 ... Check ball valves 142, 242, 542 ... Ball guides 142a, 242a ... Retainer receiving recesses 142a ', 242a' ... Vertical inner peripheral walls 142b, 242b ... Sheet receiving recesses 142c, 242c ... Ring mounting steps 143, 243, 543 ... Retainers 143a, 243a ...・ Pressure oil communication holes 144, 244, 544 ... Ball seat 145, 245 ... Stopper ring 145a, 245a ... Ring base end 145b, 245b ... Annular elastic tongue 145b ', 245b' ... Tapered contact surface 150, 250 ... Ratchet claw body 160, 260 ... Ratchet biasing spring 242d ... Ring locking convex part 242d '... Tapered surface 542a ... Caulking part 542b ... Outer peripheral tongue piece 543b ... Spring positioning mounting recess S1・ ・ ・ Drive side sprocket S2 ・ ・ ・ Driven side sprocket C ・ ・ ・ Timing chain L1 ・ ・ ・ Movable lever L2 ・ ・ ・ Fixed guide R ・ ・ ・ High pressure oil chamber P ・ ・ ・ Pressure oil supply path

Claims (5)

With a plunger that slidably protrudes from the plunger accommodation hole of the housing body toward the travel chain, and a high-pressure oil chamber that is formed between the plunger accommodation hole and the plunger and biases the plunger in the protruding direction In the hydraulic tensioner comprising a biasing spring and a check valve unit that is incorporated in the bottom of the plunger receiving hole and prevents the backflow of the pressure oil in the high pressure oil chamber,
The check valve unit is attached to a check ball valve for regulating the flow of pressure oil, a steel ball guide having an inner peripheral wall for allowing the check ball valve to float in an enclosed state, and a high pressure oil chamber side of the ball guide. A steel retainer having a pressure oil communication hole for circulating pressure oil to the high pressure oil chamber side with the check ball valve sealed in the ball guide, and a check ball mounted on the pressure oil supply side of the ball guide A steel ball seat that prevents backflow of pressure oil by seating the valve and a synthetic resin that press-fits the ball guide to the inner peripheral wall of the plunger receiving hole with the ball seat in close contact with the bottom of the plunger receiving hole. It consists of a stopper ring and
The stopper ring extends from the ring base end to be fixed to a ring mounting step formed by reducing the diameter of the outer peripheral wall of the ball guide on the high pressure oil chamber side, and accommodates the plunger. A hydraulic tensioner comprising: an annular elastic tongue contacting an inner peripheral wall of the hole.   2. The hydraulic tensioner according to claim 1, wherein the annular elastic tongue has a tapered contact surface whose diameter decreases from the high-pressure oil chamber side toward the pressure oil supply side.   3. The hydraulic tensioner according to claim 1, wherein a ring locking convex portion that locks a ring base end portion of the stopper ring is provided on the outer peripheral wall of the ball guide. 4.   The retainer is press-fitted into a retainer-receiving recess provided with a vertical inner peripheral wall that is recessed in the high-pressure oil chamber side of the ball guide and extends along the longitudinal direction of the plunger. The hydraulic tensioner according to any one of claims 1 to 3.   5. The hydraulic tensioner according to claim 1, wherein the ball seat is press-fitted into a seat-receiving recess that is recessed on the pressure oil supply side of the ball guide. 6. .

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