JP2011179623A - Hydraulic pressure tensioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic pressure tensioner in simple construction which locks a plunger by easy work. <P>SOLUTION: In the hydraulic pressure tensioner 1 which includes a tensioner body 13 which is provided with the plunger 2 which is urged in a direction projecting to outside by a plunger spring 11, a tensioner housing 4 which slidably supports the plunger 2 and a tensioner body 5 which is formed integrally with or separately from the tensioner housing 4 and which applies tension on a cam chain or a timing belt, it is formed, on one side of the plunger 2 and the tensioner housing 4, with a plane portion which extends in an urging direction of the plunger 2, and is provided, on other side of the plunger 2 and the tensioner housing 4, with a rod-shaped member sliding the plane portion so that a relative rotation of the plunger 2 and the tensioner housing 4 is made impossible accompanying slide of the plunger 2 and is provided, on the plane portion, with a groove portion which allows the relative rotation of the plunger 2 and the tensioner housing 4 in such a condition that the plunger 2 is retracted and with which the rod shaped member engages. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Hydraulic tensioners are widely used to suppress vibrations that occur when the timing chain or timing belt that transmits rotation between the crankshaft side sprocket of the engine and the camshaft side sprocket travels and maintain proper tension. ing. In this hydraulic tensioner, the plunger protruding from the housing body presses the back surface near the swinging end of the tensioner lever that is pivotally supported on the engine body so that the shoe surface of the tensioner lever is on the slack side of the chain. It is configured to apply tension by sliding contact.

  In Patent Document 1, a stepped set groove is formed on the inner periphery of the opening edge of the cylinder chamber of the tensioner housing, and a set ring that is elastically deformable in the radial direction is incorporated in the set groove in a reduced diameter state. A lock mechanism is disclosed in which a set ring is fitted into an engagement groove formed on the outer periphery of the distal end portion to hold the plunger in a pushed state.

JP 2007-32685 A

  However, the hydraulic tensioner described in Patent Document 1 has a problem that the number of parts increases and the structure becomes complicated. Further, when the plunger is locked, it is necessary to push the plunger while reducing the diameter of the set ring, and a simpler mechanism has been desired.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydraulic tensioner capable of locking a plunger with a simple structure and an easy operation.

In order to achieve the above object, the hydraulic tensioner according to claim 1 comprises:
A plunger biased in a direction protruding outward by a plunger spring;
A tensioner body comprising: a tensioner housing that slidably supports the plunger; and a tensioner body configured integrally with or separate from the tensioner housing;
A hydraulic tensioner that applies tension to the cam chain or timing belt,
One of the plunger and the tensioner housing is formed with a flat portion extending in the urging direction of the plunger,
The other of the plunger and the tensioner housing is provided with a rod-like member that slides on the flat portion so that relative rotation between the plunger and the tensioner housing becomes impossible as the plunger slides.
The flat surface portion is provided with a groove portion that allows relative rotation of the plunger and the tensioner housing in a state where the plunger is contracted and engages the rod-shaped member.

Further, the hydraulic tensioner according to claim 2 has the configuration according to claim 1,
A wall portion for restricting movement of the rod-shaped member in the biasing direction is provided at an end portion of the flat portion in the biasing direction of the plunger.

Further, the hydraulic tensioner according to claim 3 is in addition to the configuration according to claim 1 or 2,
The flat portion overlaps with the plunger spring that biases the plunger in a biasing direction.

Moreover, in addition to the structure of any one of Claims 1-3, the hydraulic tensioner of Claim 4 WHEREIN:
The plunger is slidably disposed on the outer periphery of the tensioner housing,
Forming the flat portion on the tensioner housing;
The rod-shaped member is supported by the plunger.

Moreover, in addition to the structure of any one of Claims 1-3, the hydraulic tensioner of Claim 5 WHEREIN:
The plunger is slidably disposed on the inner periphery of the tensioner housing,
Forming the planar portion on the plunger;
The rod-shaped member is supported by the tensioner housing.

Moreover, in addition to the structure of any one of Claims 1-5, the hydraulic tensioner of Claim 6 is
The rod-shaped member is formed in a substantially ring shape along the other outer peripheral surface of the plunger and the tensioner housing, and forms a part of a ring-shaped member that slides and rotates together with the other of the plunger and the tensioner housing. And

  According to the hydraulic tensioner of the first aspect, since the rod-like member can be accommodated in the groove portion simply by relatively rotating the plunger and the tensioner housing with the plunger contracted, the plunger can be locked with a simple structure and an easy operation. it can.

  According to the hydraulic tensioner of the second aspect, the plunger is prevented from coming off by providing the wall portion for restricting the movement of the bar-like member in the urging direction at the end portion of the flat portion in the urging direction. Can do.

  According to the hydraulic tensioner of the third aspect, the hydraulic tensioner can be reduced in size.

  According to the hydraulic tensioner of the fourth or fifth aspect, since the flat portion is located on the outer peripheral side of the member having the flat portion, the flat portion can be easily formed.

  Moreover, according to the hydraulic tensioner of the sixth aspect, the rod-shaped member is constituted by a part of the ring-shaped member, so that the rod-shaped member can be prevented from falling off.

It is sectional drawing of the state which attached the hydraulic tensioner of one Embodiment which concerns on this invention to the engine. (A) is a diagram of a hydraulic tensioner viewed from the rear, (b) is a diagram of the hydraulic tensioner with the base cover removed from (a), and (c) is a diagram of the hydraulic tensioner viewed from the front, (D) is an IID-IID line arrow view of (a) and (b). (A) is a diagram of a hydraulic tensioner viewed from the rear, (b) is a diagram of the hydraulic tensioner with the base cover removed from (a), and (c) is a diagram of the hydraulic tensioner viewed from the front, (D) is the IIID-IIID arrow directional view of (a) and (b). (A) is an enlarged view of a tensioner housing, (b) is a BB line arrow view of (a), (c) is a CC line arrow view of (a). (A) is the elements on larger scale of the front-end | tip part of the tensioner housing shown in FIG. 4, (b) is the figure which looked at the flange part of the tensioner housing from the front. It is a figure explaining the state which the plunger of a hydraulic tensioner protrudes. It is a figure explaining the state which the plunger of the hydraulic tensioner received the reaction force. It is a figure explaining the state which the plunger of a hydraulic tensioner receives an excessive reaction force and contracts. It is a figure for demonstrating the locking mechanism of a hydraulic tensioner, (a) is a figure which shows the state which the plunger protruded, (b) is a figure which shows the state in which the plunger was locked. (A) is sectional drawing of the state which the plunger of the hydraulic tensioner concerning 2nd Embodiment protruded, (b) is a BB arrow directional view of (a), (c) is (a). It is a figure for demonstrating the lock mechanism in a state. (A) is sectional drawing which shows the state in which the plunger of the hydraulic tensioner which concerns on 2nd Embodiment was locked, (b) is a BB arrow directional view of (a), (c) is (a It is a figure for demonstrating the locking mechanism in the state of (). (A) is sectional drawing of the state which the plunger of the hydraulic tensioner concerning 3rd Embodiment protruded, (b) is a BB arrow directional view of (a), (c) is (a). It is a figure for demonstrating the lock mechanism in a state. (A) is sectional drawing which shows the state by which the plunger of the hydraulic tensioner which concerns on 3rd Embodiment was locked, (b) is a BB arrow directional view of (a), (c) is (a It is a figure for demonstrating the locking mechanism in the state of ().

Hereinafter, each embodiment of the hydraulic tensioner of the present invention is described in detail based on a drawing.
<First Embodiment>
As shown in FIG. 1, the hydraulic tensioner 1 of the present embodiment is a vibration generated when a cam chain CC that transmits rotation is transmitted between a crankshaft side sprocket and a camshaft side sprocket of an engine 10 of a vehicle, for example, a motorcycle. The plunger 2, which is used to prevent the rotation of the cam chain CC and is biased so as to protrude toward the cam chain CC, is pivotally supported on the engine body side. By pressing the back surface in the vicinity of the swing end of the tensioner lever TL, the shoe surface of the tensioner lever TL is in sliding contact with the slack side of the cam chain CC to apply tension.

  The hydraulic tensioner 1 is urged so that the plunger 2 protrudes from the tensioner body 13 toward the cam chain CC by the plunger spring 11. The tensioner main body 13 includes a tensioner housing 4 that is disposed on the inner peripheral portion of the plunger 2 and supports the plunger 2 in a slidable manner, and a tensioner body 5 that is configured separately from the tensioner housing 4. The tensioner body 5 is connected to an oil introduction pipe 15 that introduces oil supplied from an oil pump (not shown) into the tensioner body 5 and a low-pressure oil chamber 9 that stores the oil supplied from the oil introduction pipe 15. . The tensioner housing 4 is supplied with oil in a low-pressure oil passage 6 communicating with the low-pressure oil chamber 9 and a high-pressure oil chamber 8 formed between the low-pressure oil passage 6 and the tip 45 of the tensioner housing 4 and the plunger 2. An inflow valve mechanism 7 is provided.

  In the following description, the front-rear direction means a direction (also referred to as a biasing direction) along the central axis P of the plunger, the front means the protruding direction of the plunger 2, and the rear means the contracting direction of the plunger 2. . Further, the vertical direction means the extending direction of the oil introduction pipe 15, the upper side means the inlet side of the oil introduction pipe 15, and the lower side means the outlet (introduction port 15a) side of the oil introduction pipe 15 (FIG. 3). (See (d)), the left-right direction means a direction orthogonal to the up-down direction when the hydraulic tensioner 1 is viewed from the rear.

  The plunger 2 has a bottomed cylindrical shape as shown in FIGS. 2 to 5, and has a diameter larger than that of the sleeve portion 21 at the front end of the sleeve portion 21 extending along the central axis P, and in the vicinity of the swing end of the tensioner lever TL. A contact portion 22 is formed to press the back surface. A single rod-like member 24 is stretched over the inner peripheral portion of the rear end portion of the sleeve portion 21, and a flat portion 41 formed on the outer peripheral surface of the tensioner housing 4 that slidably supports the plunger 2. Guided. Reference numeral 25 denotes an oil seal attached to the outer peripheral surface of the sleeve portion 21.

  As shown in FIGS. 4B and 4C, the tensioner housing 4 extends in the biasing direction of the plunger spring 11 so as to overlap the plunger spring 11 at four positions at intervals of 90 °, as shown in FIGS. When the flat surface portion 41 is formed and the plunger 2 slides, the rod-like member 24 is guided by the single flat surface portion 41 and the relative rotation of the plunger 2 is restricted, and the front-side wall that defines the flat surface portion 41. The plunger 42 is prevented from coming off by the portion 42 (see FIG. 4A). When the rod-shaped member 24 comes into contact with the wall portion 42, the plunger 2 protrudes most and the amount of oil stored in the high-pressure oil chamber 8 is maximized. Further, as shown in FIG. 13, the flat portion 41 is provided with a groove portion 49 formed by cutting out one side in the circumferential direction of the flat portion 41 in the vicinity of the rear side end portion, and the plunger 2 contracts. When the rod-like member 24 hung over the rear end portion of the sleeve portion 21 reaches the groove portion 49, relative rotation of the plunger 2 with respect to the tensioner housing 4 is allowed.

  Further, a hexagonal flange portion 43 is provided behind the tensioner housing 4 adjacent to the flat surface portion 41, and a male screw portion that is screwed into a female screw portion 55 formed on the tensioner body 5 at the rear side. 44 is provided, and the tensioner housing 4 is fixed to the tensioner body 5 with screws. The tensioner body 5 and the tensioner housing 4 may be fixed by press-fitting regardless of screw fixing. The surface of the flange portion 43 functions as a seat for the plunger spring 11, and the plunger spring 11 arranged so as to cover the outer peripheral portion of the plunger 2 urges the contact portion 22 of the plunger 2 toward the cam chain CC. is doing.

  2 and 3, the tensioner body 5 includes a base member 51 that is recessed so that three small chambers 9a to 9c overlap in the vertical direction from the rear side end surface 51a opposite to the tensioner housing 4. And a base cover 52 attached so as to cover the rear side end face 51a. The base member 51 and the base cover 52 are fixed by four bolts 16a and 16b, and two of the bolts 16a located at the counter electrode are used for the engine. 10 is fastened together. Three small chambers 9 a to 9 c defined by the base member 51 and the base cover 52 constitute the low-pressure oil chamber 9. An extension 51b is formed on the front side of the base member 51, and a large-diameter recess 53 is formed concentrically with the central axis P so as to wrap the tensioner housing 4 on the inner periphery of the extension 51b. Further, the base member 51 is formed with a small-diameter concave portion 54 that is further recessed from the large-diameter concave portion 53 and has a female screw portion 55 on the inner peripheral surface, and the tensioner housing 4 is screwed into the small-diameter concave portion 54 in a liquid-tight manner.

  Assuming that the three small chambers 9a to 9c are a first small chamber 9a, a second small chamber 9b, and a third small chamber 9c in this order from the bottom, the first small chamber 9a located at the lowermost position overlaps the central axis P of the plunger 2 And is open to the small-diameter concave portion 54 side, and communicates with the inside of the tensioner housing 4. The first small chamber 9a is configured to be able to communicate with the outside through an air vent hole 52a formed in the base cover 52 concentrically with the central axis P. The air vent hole 52a is always sealed with a bolt 16c.

  As shown in FIG. 3 (d), the three small chambers 9a to 9c extend in the front-rear direction and go upward from below, that is, the first small chamber 9a, the second small chamber 9b, and the third small chamber 9c. In this order, the distance from the rear side end face 51a extends long. Further, as shown in FIGS. 2B and 3B, the first small chamber 9a and the second small chamber 9b are formed so as to extend in the left-right direction, and further, the top of the first small chamber 9a. The surface is slightly inclined toward the upper right, and communicates with the second small chamber 9b through a communication hole 56a formed in the partition wall 56 at the right end, which is the highest position of the first small chamber 9a. The third small chamber 9c located at the uppermost part is connected to the oil introduction pipe 15 and communicates with the second small chamber 9b and a communication hole 57a formed in the partition wall 57 immediately below the introduction port 15a of the oil introduction pipe 15.

  Furthermore, as shown in FIGS. 2B, 3B, and 3D, the third small chamber 9c is substantially the same as the third small chamber 9c provided on the opposite side across the partition wall 58 in the left-right direction. The discharge passage 3 having a shape communicates with an outlet hole 58a formed in the rear upper end portion. As shown in FIGS. 2 (a) and 3 (a), the third small chamber 9c and the discharge passage 3 are provided between the two bolts 16a and 16b located in the upper part. The discharge passage 3 communicates with the outside through a discharge port 30 that is an extension 51 b of the base member 51 and is formed at the front lower end of the discharge passage 3. A pin insertion hole 59 that is always sealed with a bolt 16d is formed immediately above the discharge port 30. Further, the discharge passage 3 and the outlet hole 58a which is the inlet and outlet of the discharge passage 3 and the discharge port 30 have a larger cross-sectional area (flow passage area) than the introduction port 15a of the oil introduction pipe 15, and the low pressure oil chamber 9 It is set so that the oil introduced from the introduction port 15a is reliably discharged in a state where it is stored as much as possible. Further, the discharge port 30 and the tensioner housing 4 positioned below the discharge port 30 are arranged so as to be separated from each other so that the oil discharge is not hindered by the tensioner housing 4.

  The low-pressure oil chamber 9 configured in this way is supplied with oil from an oil introduction pipe 15 by an oil pump, and is first stored in the third small chamber 9c. Then, the second low-pressure oil chamber 9 is connected to the second small chamber 9c through the communication hole 57a. It is supplied to the small chamber 9b, supplied from the second small chamber 9b to the first small chamber 9a via the communication hole 56a, and supplied from the first small chamber 9a to the inside of the tensioner housing 4. In addition, excess oil introduced from the inlet 15a with the low-pressure oil chamber 9 stored to the maximum flows from the third small chamber 9c to the discharge passage 3 via the outlet hole 58a, and from the outlet 30 to the outside. Discharged.

  As shown in FIG. 4 (a), the tensioner housing 4 is formed with a collar member insertion hole 40a concentrically with the central axis P and opened at the rear end face thereof and a valve assembly hole 40b located at the central part. Further, an oil passage 80 is formed in 45 so that the valve assembly hole 40 b communicates with the high-pressure oil chamber 8.

  A collar member 60 having a through hole 61 formed concentrically with the central axis P is inserted into the collar member insertion hole 40a by being press-fitted.

  A relief valve spring 72 having a through hole 71 formed concentrically with the central axis P and a ball 74 are provided in the valve assembly hole 40b, and the relief valve spring 72 receives the collar member 60 as a seat. 73 is biased toward the distal end 45 side of the tensioner housing 4. Further, as shown in FIG. 5, the ball 74 is held by the ball holding portion 45a, and the through-hole 71 formed in the relief valve body 72 is sealed by the check valve spring 75 that receives the rear end face 45b of the tip portion 45 as a seat. It is urged toward the relief valve body 72 so as to stop.

  Returning to FIG. 4, the relief valve body 72 includes a small-diameter cylindrical portion 72 a located on the collar member 60 side, and a large-diameter cylinder slidably supported on the inner peripheral surface of the tensioner housing 4 in front of the small-diameter cylindrical portion 72 a. And a relief valve spring 73 arranged on the outer peripheral portion of the small-diameter cylindrical portion 72a urges the back surface 72c of the large-diameter cylindrical portion 72b, and the outer peripheral edge at the tip of the large-diameter cylindrical portion 72b is a relief valve. It contacts the tapered surface 45c of the tensioner housing 4 forming the seat. A plurality of V-shaped grooves 72d are formed at predetermined intervals in the circumferential direction on the outer peripheral surface of the large-diameter cylindrical portion 72b. When the relief valve body 72 is separated from the tapered surface 45c, the low-pressure oil is supplied from the high-pressure oil chamber 8 side. Allow inflow of oil to the path 6 side. The small-diameter cylindrical portion 72a also has a plurality of notches 72e formed at predetermined intervals in the circumferential direction at the rear end, and the relief valve body 72 is separated from the tapered surface 45c so that the rear end contacts the collar member 60. Even so, the oil is allowed to flow out.

  In the present embodiment, the low pressure oil passage 6 is constituted by the through hole 61 formed in the collar member 60 and the through hole 71 formed in the relief valve body 72. Also, a check valve 76 as a one-way valve is constituted by a ball 74 provided at the tip of the low-pressure oil passage 6 and a check valve spring 75, allowing oil to flow into the high-pressure oil chamber 8 and conversely high-pressure oil. Block backflow of oil from chamber 8. Furthermore, in this embodiment, the relief valve body 72 and the relief valve spring 73 constitute a relief valve 77, which is opened when the hydraulic pressure in the high pressure oil chamber 8 exceeds the set pressure, and the oil in the high pressure oil chamber 8 is reduced to low pressure oil. Return to chamber 9. The check valve 76 and the relief valve 77 constitute a valve mechanism 7.

  Referring also to FIG. 5, the tip 45 of the tensioner housing 4 has a tip flange 47 that faces the contact portion 22 of the plunger 2, and adjoins the rear of the tip flange 47 over the entire circumference. A recessed annular recess 48 is formed, and the seal member 82 is accommodated in the annular recess 48 and positioned by the front flange portion 47. The seal member 82 is provided with a V-shaped notch that opens forward in a sectional view so as to reduce friction and facilitate sliding. Note that the present invention is not limited to this, and an O-ring or X-ring may be used. Then, the space between the distal end flange portion 47 formed at the distal end portion 45 of the tensioner housing 4 and the plunger 2 is sealed by the seal member 82 to form the high pressure oil chamber 8.

  An oil passage 80 that communicates the low-pressure oil passage 6 with the high-pressure oil chamber 8 has a central axis P so as to overlap in a radial direction with a ball holding portion 45 a that holds the ball 74 and a spring holding portion 45 d that holds the check valve spring 75. Two axial oil passages 81 extending up to the high-pressure oil chamber 8 in parallel with the central axis P are vertically extended. Further, two radial oil passages 83 extending in a cruciform shape in the radial direction around the central axis P are extended at the front end flange portion 47 at the boundary with the annular recess 48, and one of the two One radial oil passage 83 extends in the vertical direction and intersects with two axial oil passages 81. The radial oil passage 83 is used as a passage through which air is discharged during the initial filling of oil, which will be described later.

  In the hydraulic tensioner 1 of this embodiment configured as described above, the force on the low pressure oil passage 6 acting on the ball 74 when the tension of the cam chain CC is weakened is the force on the high pressure oil chamber 8 acting on the ball 74, In other words, when the urging force by the check valve spring 75 and the force by the hydraulic pressure in the high pressure oil chamber 8 acting via the axial oil passage 81 are increased, the ball 74 resists the urging force by the check valve spring 75 as shown in FIG. Then, the through hole 71 opens away from the relief valve body 72. Thereby, oil flows into the high-pressure oil chamber 8 from the low-pressure oil passage 6 through the axial oil passage 81, and the plunger 2 protrudes along the central axis P and follows the cam chain CC.

  On the other hand, when the tension on the cam chain CC increases and the force on the high pressure oil chamber 8 acting on the ball 74 becomes larger than the force on the low pressure oil passage 6 acting on the ball 74, as shown in FIG. The ball 74 is urged by the relief valve body 72 and the through hole 71 is closed. Thereby, the oil stored in the high-pressure oil chamber 8 is prevented from flowing out, and a predetermined range of tension is applied to the cam chain CC.

  Further, the hydraulic pressure in the high pressure oil chamber 8 becomes excessive due to an impact from the cam chain CC, etc., and the force on the high pressure oil chamber 8 acting on the relief valve body 72, that is, the urging force by the check valve spring 75 and the axial oil. The force by the hydraulic pressure acting through the passage 81 acts on the low pressure oil passage 6 side acting on the relief valve body 72, that is, the urging force of the relief valve spring 73 and the low pressure oil acting on the back surface 72c of the large diameter cylindrical portion 72b. When the force is greater than the force due to the hydraulic pressure in the path 6, the relief valve body 72 moves away from the tapered surface 45 c of the tensioner housing 4 against the urging force of the relief valve spring 73, as shown in FIG. 8. Then, the oil in the high-pressure oil chamber 8 passes through the axial oil passage 81 and the low-pressure oil passage from the V-shaped groove 72d formed on the outer peripheral surface of the large-diameter cylindrical portion 72b of the relief valve body 72 via the notch 72e. Return to 6.

  Excess oil returned to the low pressure oil passage 6 or introduced from the oil introduction pipe 15 was stored in the third small chamber 9c located at the top of the three small chambers 9a to 9c constituting the low pressure oil chamber 9. When the oil level exceeds the outlet hole 58a formed at the upper end, the oil is discharged from the outlet hole 58a shown in FIGS. 3B and 3D to the discharge passage 3, and the discharge passage 3 shown in FIG. 2D. Is discharged to the outside of the hydraulic tensioner 1 from the discharge port 30.

Next, the lock mechanism of the hydraulic tensioner 1 will be described. FIGS. 9A and 9B are diagrams for explaining a lock mechanism of the hydraulic tensioner. FIG. 9A is a diagram illustrating a state where the plunger protrudes, and FIG. 9B is a diagram illustrating a state where the plunger is locked. Note that FIG. 9 shows only the tensioner housing 4 and the rod-like member 24 spanned on the sleeve portion 21 that slides on the flat portion 41 of the tensioner housing 4 for the sake of explanation.
As shown in FIG. 1, the hydraulic tensioner 1 that has been initially filled with oil is attached to the engine 10 with bolts 16a. However, when the plunger 2 protrudes, the hydraulic tensioner 1 interferes with the tensioner lever TL and cannot be attached. Therefore, it is necessary to attach the plunger 2 in a contracted state. Therefore, in the present embodiment, as described above, the groove portion 49 formed by cutting out one side in the circumferential direction of the flat surface portion 41 is provided in the vicinity of the rear side end portion of the flat surface portion 41, and the plunger 2 contracts. When the rod-like member 24 hung over the rear end portion of the sleeve portion 21 reaches the groove portion 49, relative rotation of the plunger 2 with respect to the tensioner housing 4 is allowed.

  Therefore, as shown in FIG. 9B, the rod-like member 24 is engaged with the groove 49 by contracting the plunger 2 and rotating the plunger 2 in the direction in which the groove 49 is provided, and resists the plunger spring 11. Then, the plunger 2 is locked to the tensioner housing 4.

  The rear end face 49a of the groove 49 has a taper surface inclined rearward. When the locked hydraulic tensioner 1 is attached to the engine 10 with a bolt 16a and the engine 10 is started, the camshaft CC is bent to the crankshaft. When a rotational force is applied from the side sprocket, an impact is applied in the direction in which the plunger 2 contracts. As a result, the rod-shaped member 24 slides along the tapered rear side end surface 49 a of the groove 49. Accordingly, the plunger 2 moves in a contracting direction while rotating, and the rod-like member 24 is removed from the groove portion 49, whereby the rod-like member 24 returns to the flat portion 41 and the plunger 2 is allowed to protrude.

  As described above, according to the present embodiment, the tensioner housing 4 is formed with the flat portion 41 extending in the biasing direction of the plunger 2, and the plunger 2 and the tensioner housing 4 as the plunger 2 slides. A rod-like member 24 that slides on the flat surface portion 41 is provided so that the relative rotation of the plunger 2 and the tensioner housing 4 are allowed in the flat portion 41 when the plunger 2 is contracted. Since the rod-like member 24 is accommodated in the groove portion 49 simply by relatively rotating the plunger 2 and the tensioner housing 4 in a contracted state with the plunger 2 contracted, the simple structure and easy work can be performed. The plunger 2 can be locked.

  Moreover, according to this embodiment, since the wall part 42 which controls the movement to the urging | biasing direction of the rod-shaped member 24 was provided in the edge part of the urging | biasing direction of the plunger 2 of the plane part 41, retaining of the plunger 2 is prevented. Can do.

  Moreover, according to this embodiment, since the plane part 41 overlaps with the plunger spring 11 which urges | biases the plunger 2 in an urging | biasing direction, axial direction length can be shortened and the hydraulic tensioner 1 is reduced in size. be able to.

  Further, according to the present embodiment, the plunger 2 is slidably disposed on the outer peripheral portion of the tensioner housing 4, the flat portion 41 is formed on the outer peripheral surface of the tensioner housing 4, and the rod 2 is supported by the plunger 2. The flat portion 41 can be easily formed.

Second Embodiment
Next, a hydraulic tensioner according to a second embodiment of the present invention will be described with reference to FIGS.
In the hydraulic tensioner 100 of the present embodiment, a cylindrical tensioner housing 104 and a tensioner body 105 are integrally formed to constitute a tensioner main body 113, and a sleeve portion 121 of the bottomed cylindrical plunger 102 is inside the tensioner housing 104. A peripheral part is slidably supported. A plunger spring 111 having a tensioner body 105 as a seat is disposed on the inner peripheral portion of the plunger 102, and the contact portion 122 of the plunger 102 is urged by the plunger spring 111 so as to protrude toward the cam chain CC. .

  A single rod-shaped member 124 is stretched over the inner periphery of the front end of the tensioner housing 104, and a flat surface portion 141 is formed on the outer peripheral surface of the sleeve portion 121 of the plunger 102 over the plunger spring 111. It is formed to extend in the urging direction of the plunger 102 so as to wrap. As a result, when the plunger 102 slides, the flat surface portion 141 of the plunger 102 is guided by the rod-shaped member 124 provided in the tensioner housing 104, and relative rotation of the plunger 102 is restricted and the flat surface portion 141 is defined. The plunger 102 is prevented from coming off by the wall 142 on the rear end side.

  Here, the flat surface portion 141 formed on the outer peripheral surface of the sleeve portion 121 of the plunger 102 is provided with a groove portion 149 formed by cutting out one side in the circumferential direction of the flat surface portion 141 in the vicinity of the front side end portion. When the plunger 102 contracts and the groove 149 reaches the rod-shaped member 124 that is stretched over the front end portion of the tensioner housing 104, the plunger 102 is allowed to rotate relative to the tensioner housing 104. Accordingly, when the plunger 102 is contracted and rotated, the groove 149 is engaged with the rod-shaped member 124, and the plunger 102 is locked to the tensioner housing 104 against the plunger spring 111 (see FIG. 11).

  When the hydraulic tensioner 100 thus locked is attached to the engine 10 with the bolts 16a and the engine 10 is started, the torque is applied to the bent cam chain CC from the crankshaft side sprocket so that the plunger 102 contracts. As a result, the tapered front end surface 149 a of the groove 149 is guided to the rod-shaped member 124. Therefore, the plunger 102 moves in a contracting direction while rotating, and the groove portion 149 is disengaged from the rod-shaped member 124, thereby allowing the plunger 102 to protrude.

  As described above, according to the present embodiment, the plunger 102 is formed with the flat portion 141 extending in the urging direction of the plunger 102, and the tensioner housing 104 has the plunger 102 and the tensioner housing 104 as the plunger 102 slides. A rod-shaped member 124 that slides on the flat surface portion 141 is provided so that the relative rotation of the plunger 102 and the tensioner housing 104 is permitted in a state in which the plunger 102 contracts. Since the rod-like member 124 is accommodated in the groove portion 149 simply by rotating the plunger 102 and the tensioner housing 104 relative to each other with the plunger 102 contracted, the simple structure and easy operation are possible. Plunger 102 can be locked.

  Further, according to the present embodiment, the plunger 102 is slidably disposed on the inner peripheral portion of the tensioner housing 104, the flat portion 141 is formed on the outer peripheral surface of the plunger 102, and the rod-shaped member 124 is supported on the tensioner housing 104. Therefore, the plane portion 141 can be easily formed.

<Third Embodiment>
Next, a hydraulic tensioner according to a third embodiment of the present invention will be described with reference to FIGS.
In the hydraulic tensioner 200 of this embodiment, a cylindrical tensioner housing 204 and a tensioner body 205 are integrally formed to constitute a tensioner body 213, and a sleeve portion 221 of a bottomed cylindrical plunger 202 is an outer periphery of the tensioner housing 204. It is slidably supported by the part. A plunger spring 211 having a tensioner body 205 as a seat is disposed on the outer peripheral portion of the plunger 202, and the contact portion 222 of the plunger 202 is urged by the plunger spring 211 so as to protrude toward the cam chain CC.

  A single rod-shaped member 224 is stretched around the inner peripheral portion of the rear end of the plunger 202, and the flat portion 241 overlaps the plunger spring 111 in a part of the circumferential direction on the outer peripheral surface of the tensioner housing 204. And extending in the urging direction of the plunger 202. Further, as shown in FIG. 12C, the flat surface portion 241 is provided with a groove portion 249 formed by cutting out one side in the circumferential direction of the flat surface portion 241 in the vicinity of the rear side end portion. When the rod-shaped member 224 reaches the groove 249, the relative rotation of the plunger 202 with respect to the tensioner housing 204 is allowed.

  Here, the rod-shaped member 224 of this embodiment forms part of the ring-shaped member 227. That is, the rod-shaped member 224 is formed by bending from the ring portion 227a of the ring-shaped member 227 formed in a ring shape along the outer peripheral surface of the plunger 202 along the flat surface portion 241, and one end of the ring portion 227a. It is formed continuously and cut off from the other end. The ring portion 227a is accommodated in a concave groove 228 formed on the outer peripheral surface of the plunger 202, and the rod-like member 224 is inserted into a through hole (not shown) that penetrates the plunger 202 and is initially pressed against the flat surface portion 241. A strain is applied to the plunger 202.

  As a result, when the plunger 202 slides, the rod-like member 224 hung around the plunger 202 is guided to the flat surface portion 241 of the tensioner housing 204, and the relative rotation of the plunger 202 is restricted and the flat surface portion 241 is defined. The plunger 202 is prevented from coming off by the wall portion 242 on the leading end side.

  A groove portion 249 is provided in the flat surface portion 241 formed on the outer peripheral surface of the tensioner housing 204 by cutting out one side in the circumferential direction of the flat surface portion 241 in the vicinity of the rear end portion. The rear end surface 249a of the groove 249 has a tapered surface inclined rearward. Therefore, when the plunger 202 contracts and the rod-shaped member 224 reaches the rod-shaped member 224 that is stretched over the front end portion of the tensioner housing 204, the plunger 102 is allowed to rotate relative to the tensioner housing 204. When the plunger 202 is rotated and the groove 249 is engaged with the rod-like member 224, the plunger 202 is locked to the tensioner housing 204 against the plunger spring 211.

  When the hydraulic tensioner 200 locked in this way is attached to the engine 10 with the bolt 16a and the engine 10 is started, the torque is applied in the direction in which the plunger 202 contracts due to the rotational force applied from the crankshaft side sprocket to the bent cam chain CC. The rod-shaped member 224 slides along the tapered rear end surface 249a of the groove 249. As a result, the plunger 202 moves in a contracting direction while rotating and the rod-like member 224 is detached from the groove portion 249, whereby the rod-like member 224 is returned to the flat surface portion 241 and the plunger 202 is allowed to protrude.

  Thus, according to this embodiment, the plunger 2 can be locked with a simple structure and an easy operation. Moreover, since the rod-shaped member 224 is configured by a part of the ring-shaped member 227, the rod-shaped member 224 can be prevented from falling off.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

1, 100, 200 Hydraulic tensioner 10 Engine 11, 111, 211 Plunger spring 13, 113, 213 Tensioner main body 2, 102, 202 Plunger 24, 124, 224 Rod member 227 Ring member 4, 104, 204 Tensioner housing 41, 141 , 241 Flat portion 42, 142, 242 Wall portion 49, 149, 249 Groove portion 5, 105, 205 Tensioner body CC Cam chain P Center axis

Claims (6)

A plunger biased in a direction protruding outward by a plunger spring;
A tensioner body comprising: a tensioner housing that slidably supports the plunger; and a tensioner body configured integrally with or separate from the tensioner housing;
A hydraulic tensioner that applies tension to the cam chain or timing belt,
One of the plunger and the tensioner housing is formed with a flat portion extending in the urging direction of the plunger,
The other of the plunger and the tensioner housing is provided with a rod-like member that slides on the flat portion so that relative rotation between the plunger and the tensioner housing becomes impossible as the plunger slides.
The hydraulic tensioner according to claim 1, wherein the flat portion is provided with a groove portion that allows the plunger and the tensioner housing to rotate relative to each other when the plunger contracts, and engages the rod-shaped member.   2. The hydraulic tensioner according to claim 1, wherein a wall portion that restricts movement of the rod-shaped member in the biasing direction is provided at an end portion of the planar portion in the biasing direction of the plunger.   The hydraulic tensioner according to claim 1, wherein the flat portion overlaps the plunger spring that biases the plunger in a biasing direction. The plunger is slidably disposed on the outer periphery of the tensioner housing,
Forming the flat portion on the tensioner housing;
The hydraulic tensioner according to claim 1, wherein the rod-shaped member is supported by the plunger. The plunger is slidably disposed on the inner periphery of the tensioner housing,
Forming the planar portion on the plunger;
The hydraulic tensioner according to any one of claims 1 to 3, wherein the rod-shaped member is supported by the tensioner housing. The rod-shaped member is formed in a substantially ring shape along the other outer peripheral surface of the plunger and the tensioner housing, and forms a part of a ring-shaped member that slides and rotates together with the other of the plunger and the tensioner housing. The hydraulic tensioner according to any one of claims 1 to 5.

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