JP2015215082A - Chain tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chain tensioner capable of supplying an oil necessary and sufficient in restarting after stop of oil supply for a long time, with a simple constitution, being miniaturized by shortening the whole, being easily manufactured, and reducing manufacturing costs.SOLUTION: A chain tensioner 100 includes a tension body 110, a plunger 120, and energizing means 140. The plunger 120 has a plunger body 126 and a check valve 150, an oil storage chamber 123 is formed at a projecting side with respect to the check valve 150 inside of the plunger body 126, and the tensioner body 110 has an oil supply hole 114. Further the plunger body 126 has a plunger through hole 124 communicating with the oil supply hole 114 through a communication passage 103, and an oil supply pipe 160 having the oil storage chamber 123 at its tip, is inserted to the plunger through hole 124.

Description

  The present invention includes a tensioner body having a cylindrical plunger receiving hole opened on one side, a cylindrical plunger slidably inserted into the plunger receiving hole, and the plunger receiving hole and the rear end side of the plunger. The present invention relates to a chain tensioner that includes an urging means that is retractably accommodated in a pressure oil chamber formed therebetween and urges a plunger in a plunger protruding direction, and appropriately maintains a chain tension.

  Conventionally, it is common to use a chain tensioner that appropriately maintains the tension of the chain. For example, a transmission chain such as a roller chain suspended endlessly between sprockets provided in each of the crankshaft and camshaft in the engine room. In a chain guide mechanism that performs sliding guide with a travel guide shoe, a swinging chain guide having a travel guide shoe is urged by a chain tensioner in order to maintain a proper tension.

  For example, as shown in FIG. 6, a timing chain CH is endlessly suspended between a drive sprocket S1 attached to a crankshaft in an engine room and a pair of driven sprockets S2 and S3 attached to a camshaft. The timing chain CH is guided by the swinging chain guide G1 and the fixed chain guide G2 to constitute a chain guide mechanism. The fixed chain guide G2 is fixed in the engine room by two mounting shafts B1 and B2, and the swing chain guide G1 is swingable in the suspension plane of the timing chain CH around the mounting shaft B0 in the engine room. Is attached. The chain tensioner 500 presses the oscillating chain guide G1 to properly maintain the tension of the timing chain CH and suppress vibrations.

  A known chain tensioner 500 used for such a chain guide mechanism includes, for example, a tensioner body 510 having a cylindrical plunger receiving hole 511 that is open on one side, and a plunger receiving hole 511 as schematically shown in FIG. A cylindrical plunger 520 slidably inserted into the cylindrical surface 513 and an urging means for urging the plunger 520 from the plunger housing hole 511 in the plunger protruding direction are provided. The urging means includes a coil spring 540 that is accommodated in the cylindrical recess 521 of the cylindrical plunger 520 and compressed between the bottom 512 of the plunger accommodation hole 511.

  By supplying oil from the oil supply hole 514 provided in the tensioner body 510, the pressure oil chamber 501 formed between the plunger accommodation hole 511 and the plunger 520 is filled with oil, and the plunger 520 is plungerd by the oil. While energizing in the protruding direction, the check valve 550 (schematically, only the check ball is shown) prevents oil from flowing out from the oil supply hole 514. As a result, the oil flows through a slight gap between the plunger 520 and the plunger housing hole 511 as the plunger 520 reciprocates, and a damping effect is obtained in which the reciprocation of the plunger 520 is attenuated by the flow path resistance.

  In such a known chain tensioner 500, if the oil supply is stopped for a long time after the oil supply is stopped (in the case of an engine, the engine is stopped), a time lag occurs in the oil supply immediately after the next start-up. Even if the plunger 520 reciprocates, the oil in the pressure oil chamber 501 only leaks and is not newly supplied, and the oil in the pressure oil chamber 501 disappears, so that the damping force by the oil of the plunger 520 does not act, and the timing There is a problem that the chain CH may vibrate greatly to generate an abnormal sound or the timing chain CH may be damaged.

  For this reason, a storage oil chamber is provided inside the plunger, and oil is supplied from the storage oil chamber to the pressure oil chamber, leaving a certain amount of oil in the storage oil chamber without leaking, and starting after a long stop. It is well known that oil that remains in the reservoir oil chamber is supplied to the pressure oil chamber even immediately after it, maintains the damping force of the plunger oil, suppresses chain vibration, and prevents damage (Patent Document 1, (See 2nd grade.)

JP 09-177907 A Japanese Patent No. 4376278

  However, in the case of the technique described in Patent Document 1, most of the oil supplied from the reservoir oil chamber (oil reserve chamber 9) to the pressure oil chamber (high pressure chamber 14) immediately after the start is reciprocated by the plunger. Along with this, the oil supply hole (supply hole 12) formed in the tensioner body (tensioner body 3) or the tip of the plunger leaks from the pressure oil chamber through the gap between the plunger and the plunger accommodation hole (plunger chamber 4). Since the oil leaks from the side to the outside, the oil in the reservoir oil chamber decreases. For this reason, it is necessary to leave the necessary oil in the storage oil chamber during the time lag until the oil is supplied from the oil supply hole immediately after startup, but when the oil supply is stopped (when the engine is stopped) Since oil in the reservoir oil chamber (oil reserve chamber 9) leaks through the plunger through hole (oil supply hole 10) on the plunger side wall and the oil supply hole on the tensioner body, the oil surface can be maintained above the oil supply hole. Can not. Therefore, it is necessary to make a large space for the storage oil chamber, and the whole cannot be shortened, and there is a problem that it is difficult to reduce the size.

  Further, in the technique described in Patent Document 1, when the chain tensioner is installed so that the plunger protruding direction (plunger longitudinal direction) is inclined with respect to the horizontal direction, the plunger through hole in the rotation direction around the plunger shaft is provided. Depending on the position, the height of the plunger through hole varies in the vertical direction when the oil supply is stopped (when the engine is stopped), and as a result, the height of the oil surface of the oil held in the reservoir oil chamber varies. Become. Therefore, in order to suppress oil leakage when the oil supply is stopped, it is necessary to provide a mechanism for regulating the position of the plunger in the rotation direction with respect to the tensioner body so that the position of the plunger through hole in the vertical direction becomes the highest. Yes, when such a rotation prevention mechanism for the plunger is provided, the processing load and the assembly load increase, and in addition to the cost increase, the plunger always slides against the tensioner body at the same position. Therefore, local sliding wear occurs, and the function of the chain tensioner may be impaired.

  In the case of the technique described in Patent Document 2, by providing the oil supply hole (oil supply hole 122) upward and obliquely forward, at least inside the pressure oil chamber (high pressure oil chamber R). The oil leaking through the gap between the plunger and the plunger receiving hole is prevented from leaking outside through the oil supply hole (oil supply hole 122). However, this method cannot be applied when oil is supplied from other than above, and there is a problem that the position of the oil supply hole (oil supply hole 122) is limited.

  Therefore, the present invention solves these problems, and with a simple configuration, it is possible to supply necessary and sufficient oil at the time of restart after stopping oil supply for a long time, and shortening the whole, An object of the present invention is to provide a chain tensioner that can be reduced in size, can be easily manufactured, and can reduce manufacturing costs.

  A chain tensioner according to the present invention includes a tensioner body having a cylindrical plunger receiving hole that is open on one side, a cylindrical plunger that is slidably inserted into the plunger receiving hole, and a rear end of the plunger receiving hole and the plunger. A chain tensioner that is retractably accommodated in a pressure oil chamber formed between the end side and a biasing means that biases the plunger in the plunger protruding direction, wherein the plunger includes a plunger body, A check valve provided inside the plunger body, a reservoir oil chamber is formed on the protruding side from the check valve inside the plunger body, an oil supply hole is provided in the tensioner body, The plunger body is formed with a plunger through hole that communicates with the oil supply hole via a communication passage. The hole, by oil supply pipe to which the tip is disposed in the reservoir oil chamber is inserted, is intended to solve the above problems.

According to the chain tensioner according to the first aspect of the present invention, the oil supply pipe in the reservoir oil chamber is inserted into the plunger through hole formed in the plunger main body so that the tip of the oil supply pipe in the reservoir oil chamber is inserted. Because the tip position can be set freely, the oil supply is stopped (when the engine is stopped) regardless of the position of the plunger through hole in the plunger longitudinal direction and the position of the plunger in the rotational direction relative to the tensioner body. In this case, oil leakage from the oil storage chamber can be suppressed, and a sufficient amount of oil can be held in the oil storage chamber while realizing a downsizing of the plunger with a simple configuration.
Further, since it is not necessary to provide a rotation prevention mechanism for the plunger in order to secure the amount of oil retained in the reservoir oil chamber, an increase in cost due to the installation of the rotation prevention mechanism can be avoided, and at the same position. Local sliding wear that tends to occur when the plunger slides with respect to the tensioner body can be prevented.

According to the chain tensioner according to the second aspect of the present invention, the plunger through hole is a round hole, and the oil supply pipe is formed in a cylindrical shape, so that when inserting the oil supply pipe into the plunger through hole, Manufacturing and assembly burdens can be further reduced, for example, it is not necessary to adjust the phase in the rotational direction of the oil supply pipe with respect to the plunger through hole and the insertion direction.
According to the chain tensioner according to the third aspect of the present invention, the communication path between the oil supply hole and the plunger through hole is constituted by the annular communication adjustment groove formed on the outer periphery of the plunger body, whereby the plunger for the tensioner body is formed. Regardless of the phase of the rotation direction, the oil can smoothly flow between the oil supply hole of the tensioner body and the plunger through hole.
According to the chain tensioner according to the fourth aspect of the present invention, the oil supply pipe is inserted into the oil supply hole so that the oil supply pipe extends toward the front end corner of the storage oil chamber far from the plunger through hole. This makes it possible to insert the oil supply pipe with a sufficient angle with respect to the plunger side wall while setting the tip position of the oil supply pipe in the oil storage chamber high. While holding the oil, it is possible to ensure a degree of freedom in design regarding the thickness and strength of the plunger side wall. That is, when the insertion angle of the oil supply pipe relative to the plunger side wall is shallow, the plunger side wall is easily damaged by the insertion of the oil supply pipe. However, in the invention according to claim 4, the oil supply pipe is set at a sufficient angle. Since it can be inserted, the degree of freedom in design regarding the thickness and strength of the plunger side wall can be ensured.

The perspective view which shows the chain tensioner which concerns on one Embodiment of this invention. The perspective view which shows a plunger. Sectional drawing which shows a chain tensioner. Explanatory drawing of the residual oil of a chain tensioner. Explanatory drawing of the residual oil in a comparative example. Explanatory drawing of the chain tensioner used for the chain guide mechanism of an engine. Schematic explanatory drawing of the conventional chain tensioner.

  A chain tensioner 100 according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 to 3, the chain tensioner 100 includes a tensioner body 110 having a cylindrical plunger receiving hole 111 that is open on one side, and a cylindrical plunger 120 that is slidably inserted into the plunger receiving hole 111. And a coil spring 140, which is an urging means for urging the plunger 120 in the plunger protruding direction, being accommodated in a pressure oil chamber 101 formed between the plunger accommodation hole 111 and the rear end side of the plunger 120. It has.

  The chain tensioner 100 is fixed in an engine having a chain guide mechanism. For this purpose, the tensioner body 110 is formed with an attachment portion having an attachment hole through which a bolt or the like is inserted.

  Further, a pin hole penetrating in the radial direction is provided in the vicinity of the open portion of the plunger accommodation hole 111, and a plunger 120 is inserted and fixed by inserting a pressing pin (not shown) into the pin hole. Thus, it is possible to perform operations such as fixing in the engine with the plunger 120 incorporated.

  The plunger 120 has a plunger main body 126 that is rotatably disposed in the plunger receiving hole 111 and a check valve 150 provided inside the plunger main body 126. A check valve 150 is arranged inside the plunger main body 126, and a reservoir oil chamber 123 is formed on the protruding side thereof. The check valve 150 includes a ball seat, a check ball that can be in close contact with the oil flow path of the ball seat, and a retainer that guides the check ball.

  As shown in FIGS. 2 and 3, an annular communication adjustment groove 103 is formed on the outer periphery of the plunger body 126. The communication adjusting groove 103 functions as a communication path that connects a round hole-shaped plunger through-hole 124 formed in the side wall of the plunger main body 126 and an oil supply hole 114 described later. The oil supply hole 114 and the plunger through hole 124 are formed to have a vertical width that allows communication.

  A metal and cylindrical oil supply pipe 160 whose tip is disposed in the reservoir oil chamber 123 is inserted into the plunger through hole 124 and fixed to the plunger through hole 124. The oil supply pipe 160 extends linearly toward the front end corner of the oil storage chamber 123 on the side far from the plunger through hole 124.

  As shown in FIG. 3, the coil spring 140 is configured such that one end is seated on the bottom of the plunger receiving hole 111 and the other end is seated on the outer periphery of the retainer of the check valve 150. Is effectively secured as a space for expansion and contraction of the coil spring 140.

  The tensioner body 110 is used by being fixed to a mounting wall (not shown) in the engine, and an oil supply hole 114 is provided in the direction of the mounting wall.

In the chain tensioner 100 of the present embodiment obtained in this way, an oil supply pipe 160 whose tip is disposed in the reservoir oil chamber 123 is inserted into the plunger through hole 124 formed in the plunger main body 126. Regardless of the position where the plunger through hole 124 is formed in the longitudinal direction of the plunger and the position of the plunger 120 in the rotational direction relative to the tensioner body 110, the oil is retained in the oil storage chamber 123 when the oil supply is stopped (when the engine is stopped). The position of the oil surface P of the oil can be maintained at a high position.
That is, when the chain tensioner 100 is installed with the front end of the plunger main body 126 facing upward as shown in FIG. 4 (a), or when the front end of the plunger main body 126 is inclined upward as shown in FIG. 4 (b). When the chain tensioner 100 is installed in a state of being directed or when the plunger 120 is rotated 180 ° from the state of FIG. 4B as shown in FIG. 4C, the oil is supplied as shown in FIG. Compared with the case where the pipe 160 is not inserted, the position of the oil surface P of the oil retained in the reservoir oil chamber 123 can be maintained at a high position.
FIG. 5 shows a comparative example in which the oil supply pipe 160 is not inserted. FIG. 5A shows a case where the chain tensioner 100 is installed with the front end of the plunger main body 126 facing obliquely upward. FIG. 5B shows a case where the chain tensioner 100 is installed with the front end of the plunger main body 126 facing obliquely upward, and FIG. 5C shows that the plunger 120 is moved 180 ° from the state of FIG. The case where it rotated is shown.

The embodiment described above is a specific example of the chain tensioner according to the present invention, but the chain tensioner according to the present invention is not limited thereto, and the shape, position, dimension, arrangement relationship, etc. of each component member, Various modifications are possible.
For example, in the above-described embodiment, the oil supply pipe is described as being made of metal, but any material may be used for the oil supply pipe, and in the above-described embodiment, the oil supply pipe is linear and cylindrical. As described above, the specific shape of the oil supply pipe may be any shape as long as it is hollow. For example, the oil supply pipe may be curved. The oil supply pipe may be fixed to the plunger through hole by any method such as press fitting.
Further, in addition to the configuration of the above-described embodiment, another configuration incorporated in a chain tensioner such as a ratchet mechanism may be added.
In the above-described embodiment, the communication passage that communicates the plunger through hole and the oil supply hole is described as an annular communication adjustment groove formed on the outer periphery of the plunger body. The specific mode may be any as long as it allows the plunger through hole and the oil supply hole to communicate with each other. For example, a communication path may be formed from an annular communication adjustment groove on the inner peripheral side of the tensioner body.
In the embodiment described above, the communication adjustment groove is formed in an annular shape over the entire circumference in the circumferential direction of the plunger body. However, the communication adjustment groove is provided in a part of the circumferential direction, and the communication adjustment groove is formed in the entire circumference. It is good also as a shape which does not extend.
In the above-described embodiment, the plunger is provided to be rotatable about the plunger axis with respect to the tensioner body, that is, the plunger is not rotated with respect to the tensioner body. It does not matter if a rotation stop mechanism is provided.
Further, the chain tensioner of the present invention is a chain guide mechanism that performs a sliding guide using a travel guide shoe on a transmission chain such as a roller chain suspended endlessly between sprockets provided on a crankshaft and a camshaft in an engine room. Not limited to the application, the sliding guide of the chain may be performed directly at the tip of the plunger.
Furthermore, the present invention is not limited to a chain transmission mechanism, and may be applied to a similar transmission mechanism such as a belt or rope. For applications where it is required to supply sufficient oil when restarting after a long period of oil supply stoppage. For example, it can be used in various industrial fields.

100, 500 ... Chain tensioners 101, 501 ... Pressure oil chamber 103 ... Communication adjustment groove (communication path)
110, 510 ... tensioner bodies 111, 511 ... plunger receiving hole 512 ... bottom 513 ... cylindrical surface 114, 514 ... oil supply holes 120, 520 ... plunger 521 ... cylindrical Recessed portion 123 ... Oil storage chamber 124 ... Plunger through hole 126 ... Plunger body 140, 540 ... Coil spring (biasing means)
150, 550 ... Check valve 160 ... Oil supply pipe S1 ... Drive sprocket S2 ... Follower sprocket S3 ... Follower sprocket CH ... Timing chain G1 ... Swing chain guide G2 ...・ Fixed chain guide B0, B1, B2 ... Mounting shaft P ... Oil surface

Claims (4)

A tensioner body having a cylindrical plunger receiving hole opened on one side, a cylindrical plunger slidably inserted into the plunger receiving hole, and formed between the plunger receiving hole and the rear end side of the plunger. A chain tensioner that is retractably accommodated in the pressure oil chamber and includes a biasing means that biases the plunger in the plunger protruding direction,
The plunger has a plunger main body and a check valve provided in the plunger main body,
A storage oil chamber is formed on the protruding side of the check valve inside the plunger body,
The tensioner body is provided with an oil supply hole,
The plunger body is formed with a plunger through hole communicating with the oil supply hole via a communication path.
A chain tensioner, wherein an oil supply pipe whose tip is disposed in the reservoir oil chamber is inserted into the plunger through hole. The plunger through hole is a round hole,
The chain tensioner according to claim 1, wherein the oil supply pipe is formed in a cylindrical shape.   3. The chain tensioner according to claim 1, wherein the communication path includes an annular communication adjustment groove formed on an outer periphery of the plunger body.   The chain tensioner according to any one of claims 1 to 3, wherein the oil supply pipe extends toward a front end corner of the oil storage chamber far from the plunger through hole. .

Images