JP2016020734A - Feed screw type tensioner device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple feed screw type tensioner device having high general-purpose structure without needing an oil supply passage on a transmission belt case side.SOLUTION: In a feed screw type tensioner device that presses an endless transmission belt 12 for transmitting power with advance of a pressing body 31 to always feed tension to the endless transmission belt 12, oil guide grooves 24, 25 substantially directed in an axial direction are formed on at least the outer peripheral surface and inner peripheral surface of an upper half part, on a cylindrical wall 23 of a tensioner housing 21 attached to a transmission belt case 3c.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lead screw tensioner device.

  The feed screw type tensioner device is an endless transmission belt that travels as a rotating body is rotated by a pressing body that is screwed into a rotating body that is rotatably supported in a tensioner housing. Is a tensioner device that always applies tension to the endless transmission band by pressing.

Lubricating oil needs to be supplied to the bearing portion where the rotating shaft body in the tensioner housing of the tensioner device as described above is rotatably supported.
Therefore, there is an example (see Patent Document 1) in which an oil passage is formed in the wall of the tensioner housing to guide the lubricating oil to the bearing portion.

Japanese Patent No. 4245237

A feed screw type tensioner device disclosed in Patent Document 1 is a cam chain tensioner device that applies tension to a cam chain in an overhead cam type internal combustion engine, and an oil passage that guides lubricating oil to a bearing portion in a wall of the tensioner housing Is formed.
It is necessary to design an oil supply passage communicating with the oil passage of the tensioner housing in the wall of the chain case of the engine case of the internal combustion engine.

  The feed screw type tensioner device used for the internal combustion engine is a general-purpose component that is used in a plurality of types of internal combustion engines. In some cases, the type of internal combustion engine that can be employed is limited, so that versatility is reduced and the cost is increased.

  The present invention has been made in view of the above points, and the object of the present invention is to provide a simple feed screw tensioner device having a highly versatile structure without requiring an oil supply passage on the transmission band case side. .

In order to achieve the above object, the invention according to claim 1
A tensioner housing (21) which has a bottomed cylindrical shape by a bottom wall (22) and a cylindrical wall (23) and is attached to the transmission band case (3c) with the central axis (X) of the cylindrical wall (23) oriented substantially horizontally. )When,
A rotating shaft body (30) rotatably supported at one end in a bearing recess (22d) formed at the center of the bottom surface of the bottom wall (22),
The rotation is restricted by a guide member (35) provided in the opening of the cylindrical wall (23) by screwing with the rotary shaft (30) and on the central axis (X) of the cylindrical wall (23). A pressing body (31) that is pivotally supported, and advances and retreats in the axial direction by rotation of the rotating shaft body (30), and a torsion spring (45) that biases the rotating shaft body (30) in one rotation direction. With
In the feed screw type tensioner device that constantly applies tension to the endless transmission band (12) by pressing the endless transmission band (12) for transmitting power by the advancement of the pressing body (31),
Oil guide grooves (24, 24) substantially oriented in the axial direction at least on the outer peripheral surface and inner peripheral surface of the upper half of the cylindrical wall (23) of the tensioner housing (21) attached to the transmission band case (3c). 25) is a feed screw type tensioner device.

The invention according to claim 2
In the lead screw type tensioner device according to claim 1,
The oil guide grooves (24, 25) are arranged in a plurality of adjacent directions in the circumferential direction of the cylindrical wall (23) to form a continuous wave shape.

The invention described in claim 3
In the lead screw tensioner device according to claim 2,
The wave shape formed by the oil guide grooves (24, 25) is formed over the entire circumference of the cylindrical wall (23).

The invention according to claim 4
In the lead screw type tensioner device according to claim 2 or 3,
The oil guide groove (25) on the inner peripheral surface of the cylindrical wall (23) extends to the bottom surface of the bottom wall (22).

The invention according to claim 5
In the lead screw type tensioner device according to any one of claims 1 to 4,
A plurality of grooves (26) oriented radially from the axis center are formed on the bottom surface of the bottom wall (22).

The invention described in claim 6
In the lead screw type tensioner device according to any one of claims 1 to 5,
At least the upper half of the cylindrical wall (23) is formed with a slit groove (27) cut in the axial direction from the edge of the opening at the front end to the bearing recess (22d) of the bottom wall (22). And

The invention described in claim 7
In the lead screw type tensioner device according to any one of claims 1 to 6,
The outer peripheral surface of the cylindrical wall (23) is formed with a conical surface so that the outer diameter decreases from the bottom wall (22) side toward the tip opening edge,
The inner peripheral surface of the cylindrical wall (23) is characterized in that a conical surface is formed so that the inner diameter increases from the bottom wall (22) side toward the tip opening edge.

The invention described in claim 8
In the lead screw type tensioner device according to claim 7,
The tensioner housing (21) is formed by a die that is divided into two in the axial direction of the central axis (X) of the cylindrical wall (23).

The invention according to claim 9
In the lead screw type tensioner device according to any one of claims 1 to 8,
One end of the rotary shaft body (30) is rotatably supported via a bowl-shaped bearing member (40) fitted to the bearing recess (22d) of the bottom wall (22),
A plurality of notches (41) are formed in the circumferential direction in the opening edge of the flange-shaped bearing member (40).

The invention according to claim 10 is:
In the lead screw type tensioner device according to claim 9,
A shaft end surface (30f) facing and contacting the bottom surface of the hook-shaped bearing member (40) at the shaft end portion (30d) of the rotary shaft body (30) rotatably thrust-bearing on the hook-shaped bearing member (40). Is processed and formed to have the required surface roughness.

The invention according to claim 11
In the lead screw type tensioner device according to claim 10,
The shaft end surface (30f) of the rotary shaft (30) is processed and formed to have a surface roughness such that the maximum height roughness Rz is 7 or more and 26 or less.

The invention according to claim 12
In the lead screw type tensioner device according to claim 9 or 10,
A shaft end surface (30f) facing and contacting the bottom surface of the hook-shaped bearing member (40) at the shaft end portion (30d) of the rotary shaft body (30) rotatably thrust-bearing on the hook-shaped bearing member (40). Is characterized in that an oil groove (30v) is formed along the outer peripheral edge (30fe) inside the outer peripheral edge (30fe) of the coaxial end face (30f).

The invention according to claim 13
The lead screw tensioner device according to claim 12,
The oil groove (30v) is composed of a plurality of arcuate oil grooves (30v) divided in the circumferential direction.

The invention according to claim 14
The lead screw tensioner device according to claim 13,
A slit locking hole (30e) for locking one end of the torsion spring (45) is cut in the shaft end portion (30d) of the rotating shaft body (30) from the shaft end surface (30f) along the axis center. Formed with
The arcuate oil groove (30v) is formed away from the slit locking hole (30e).

  According to the lead screw type tensioner device according to claim 1, at least the outer peripheral surface and the inner peripheral surface of the upper half of the cylindrical wall (23) of the tensioner housing (21) attached to the transmission band case (3c) The oil guide grooves (24, 25) that are substantially oriented in the direction are formed, so that the oil that adheres to the inner surface of the transmission band case (3c) and flows down is oriented almost horizontally on the center axis (X) of the tensioner housing (21). The oil that reaches the upper outer peripheral surface of the cylindrical wall (23) flows down to the upper outer peripheral surface of the cylindrical wall (23) and the oil scattered on the upper outer peripheral surface of the cylindrical wall (23) directly adheres. The oil guide groove (24) formed on the outer peripheral surface enters the oil guide groove (24), flows to the opening end of the cylindrical wall (23), and wraps around the opening end to enter the inside of the cylindrical wall (23). It is guided by the oil guide groove (25) on the inner peripheral surface side, is transmitted along the inner peripheral surface to the bottom wall (22), and reaches the bottom wall (22). Oil can be efficiently supplied to the formed bearing recess (22d) to lubricate the bearing portion on which one end of the rotating shaft (30) is rotatably supported to prevent wear.

  An oil passage is not formed in the wall of the tensioner housing (21), the structure is simple, and there is no need to design an oil supply passage on the transmission band case (3c) side. It is possible to maintain high versatility without being limited by the type, and to reduce costs.

  According to the feed screw type tensioner device according to claim 2, the oil guide grooves (24, 25) are arranged in a plurality of adjacent directions in the circumferential direction of the cylindrical wall (23) to form a continuous wave shape. Most of the oil that has reached the upper outer peripheral surface of (23) will be guided into the plurality of oil guide grooves (24, 25), and more efficiently supplied to the bearing part of the rotating shaft body (30). Can do.

  According to the feed screw type tensioner device of the third aspect, since the wave shape formed by the oil guide groove (24, 25) is formed over the entire circumference of the cylindrical wall (23), the tensioner housing (21 ) On the transmission belt case (3c) with the central axis (X) of the cylindrical wall (23) generally horizontal, regardless of the mounting angle of the cylindrical wall (23), the upper outer peripheral surface and inner peripheral surface Since the oil guide grooves (24, 25) can always be positioned in the case, the degree of freedom in mounting the tensioner housing (21) is increased, and the versatility is improved.

  According to the feed screw tensioner device of the fourth aspect, the oil guide groove (25) on the inner peripheral surface of the cylindrical wall (23) extends to the bottom surface of the bottom wall (22). The oil that has entered the inside of the cylindrical wall (23) around the open end of the wall (23) is guided to the oil guide groove (25) on the inner peripheral surface and formed on the bottom surface of the bottom wall (22). The concave portion (22d) is reliably supplied, and the bearing portion of the rotating shaft (30) can be sufficiently lubricated.

  According to the feed screw type tensioner device of claim 5, since the bottom surface of the bottom wall (22) of the tensioner housing (21) is formed with a plurality of grooves (26) directed radially from the axial center, When the oil that has entered the inner peripheral surface of the cylindrical wall (23) is guided by the oil guide groove (25) on the inner peripheral surface and reaches the bottom wall (22), grooves are formed radially on the bottom surface of the bottom wall. The oil is guided to the strip (26), collected in the central bearing recess (22d), and concentrated on the bearing portion of the rotating shaft (30) to efficiently supply oil.

  According to the feed screw type tensioner device according to claim 6, at least the upper half of the cylindrical wall (23) is a slit cut in the axial direction from the edge of the opening to the bearing recess (22d) of the bottom wall (22). Since the groove (27) is formed, a part of the oil that has reached the upper outer peripheral surface of the cylindrical wall (23) enters the slit groove and flows out to the inner peripheral surface of the cylindrical wall (23). ) Can be directly supplied to the bearing recess (22d) in which the oil has been cut, and the amount of oil supplied to the bearing portion of the rotating shaft (30) can be increased.

  According to the feed screw tensioner device of the seventh aspect, the outer peripheral surface of the cylindrical wall (23) is formed with a conical surface so that the outer diameter decreases from the bottom wall (22) side toward the tip opening edge. Therefore, the oil that has reached the upper outer peripheral surface of the cylindrical wall (23) is urged toward the opening end of the cylindrical wall (23) through the conical surface, flows around the opening end, and enters the inside of the cylindrical wall (23). The oil that has flowed in is urged toward the bottom wall (22) through a conical surface formed so that the inner diameter increases from the bottom wall side of the inner peripheral surface of the cylindrical wall (23) toward the edge of the tip opening. The oil supply amount to the bearing portion of the rotating shaft body (30) can be increased.

  According to the feed screw type tensioner device of the eighth aspect, the tensioner housing (21) is molded by a die divided into two in the axial direction of the central axis (X) of the cylindrical wall (23). The oil guide grooves (24, 25) that are substantially oriented to each other can be simultaneously molded by the mold, and the cylindrical wall (23) that is tapered by the outer peripheral surface and the inner peripheral surface forming a conical surface is punched in the axial direction. And can be easily molded.

  According to the feed screw type tensioner device of the ninth aspect, the rotary shaft body (40) is interposed via the flange-shaped bearing member (40) fitted in the bearing concave portion (22d) formed in the bottom center of the bottom wall (22). 30) is pivotally supported at one end to prevent the bearing recess (22d) formed by the tensioner housing (21) from directly supporting the rotating shaft body (30) and wearing it, and smoothly rotating. And by forming a plurality of notches (41) in the circumferential direction at the opening edge of the bowl-shaped bearing member (40), the bearing portion of the rotating shaft body (30) that is inside the bowl-shaped bearing member (40) is formed. Oil can be smoothly supplied through the notch (41).

According to the feed screw type tensioner device of the tenth aspect, the hook-shaped bearing member (40) at the shaft end (30d) of the rotary shaft body (30) rotatably thrust-supported by the hook-shaped bearing member (40). Since the shaft end surface (30f) facing and contacting the bottom surface of the shaft is formed to have the required surface roughness, the shaft end surface (30f) of the required surface roughness of the rotating shaft (30) has the same surface roughness. A thrust bearing is brought into contact with the bottom surface of the bowl-shaped bearing member (40) while oil is held on the uneven surface.
Therefore, the rotational resistance generated by the relative rotation of the rotating shaft body (30) with respect to the bowl-shaped bearing member (40) increases due to the surface roughness of the shaft end surface (30f) of the rotating shaft body (30). ) To maintain the rotational resistance suppressed by the lubrication by the oil held on the uneven surface of the thrust bearing, and it is possible to operate the feed screw mechanism more reliably and to suppress wear in the thrust bearing. Can do.

According to the lead screw type tensioner device of the eleventh aspect, the shaft end surface (30f) of the rotary shaft body (30) is formed to have a surface roughness such that the maximum height roughness Rz is 7 or more and 26 or less. Therefore, the rotating shaft body (30) is in a state where oil is appropriately held on the uneven surface having a surface roughness such that the maximum height roughness Rz of the shaft end surface (30f) is 7 or more and 26 or less. A thrust bearing is brought into contact with the bottom surface of the bowl-shaped bearing member (40).
Therefore, the rotational resistance generated by the relative rotation of the rotating shaft body (30) with respect to the bowl-shaped bearing member (40) increases due to the surface roughness of the shaft end surface (30f) of the rotating shaft body (30). ) Maximum height roughness Rz is 7 or more and 26 or less, and it is suppressed by lubrication with oil held on an uneven surface having a surface roughness, and a thrust bearing can be maintained while maintaining an appropriate rotational resistance. The feed screw mechanism can be operated more reliably, and wear in the thrust bearing can be suppressed.

When the shaft end surface 30f of the rotary shaft 30 is processed and formed only in surface roughness, if the maximum height roughness Rz is smaller than 7 or larger than 26, the cup is related to the surface roughness and the oil holding force. It is difficult to obtain an appropriate rotational resistance in the relative rotation of the rotating shaft 30 with respect to the washer 40.
The maximum height roughness Rz is defined in JIS B601: 2001.

According to the feed screw type tensioner device of the twelfth aspect, the hook-shaped bearing member (40) at the shaft end (30d) of the rotary shaft body (30) rotatably thrust-supported by the hook-shaped bearing member (40). An oil groove (30v) is formed along the outer peripheral edge (30fe) on the inner side of the outer peripheral edge (30fe) of the coaxial end face (30f) on the shaft end face (30f) facing and contacting the bottom surface of the oil groove. (30v) is formed on the shaft end surface (30f) independently from the outer peripheral edge (30fe), so that oil easily accumulates in the oil groove (30v), and the shaft end surface (30f) of the rotating shaft body (30) The thrust bearing comes into contact with the bottom surface of the bowl-shaped bearing member (40) in a state where the oil is appropriately held on the surface by the oil groove (30v).
Therefore, in the relative rotation of the rotating shaft body (30) with respect to the bowl-shaped bearing member (40), the oil is appropriately held on the shaft end surface (30f), so that a thrust bearing can be maintained while maintaining an appropriate rotational resistance. In addition, the feed screw mechanism can be operated more reliably, and wear in the thrust bearing can be suppressed.

  According to the feed screw tensioner device of the thirteenth aspect, the oil groove (30v) is composed of a plurality of arcuate oil grooves divided in the circumferential direction, so that the shaft end surface (30f) of the rotary shaft body (30) is provided. A thrust bearing that can maintain oil in a well-balanced manner over the entire surface and effectively maintain an appropriate rotational resistance in the relative rotation of the rotating shaft body (30) with respect to the bowl-shaped bearing member (40). can do.

According to the feed screw type tensioner device of the fourteenth aspect, a slit locking hole (30e) for locking one end of the torsion spring (45) is formed in the shaft end portion (30d) of the rotary shaft body (30). Even when it is formed by cutting along the axial center from the end face (30f), the arcuate oil groove (30v) is formed away from the slit locking hole (30e), so the arcuate oil groove (30v) Since it is formed on the shaft end surface (30f) independently from the slit locking hole (30e), oil easily collects in the arcuate oil groove (30v), and the shaft end surface (30f) of the rotating shaft body (30) The thrust bearing comes into contact with the bottom surface of the bowl-shaped bearing member (40) in a state where the oil is appropriately held on the surface by the oil groove (30v).
Therefore, in the relative rotation of the rotating shaft body (30) with respect to the bowl-shaped bearing member (40), the thrust bearing can be maintained while maintaining an appropriate rotational resistance by the oil appropriately held on the shaft end face (30f), The feed screw mechanism can be operated more reliably, and wear in the thrust bearing can be suppressed.

It is a figure showing a valve drive system of an internal-combustion engine to which a feed screw type tensioner device concerning one embodiment of the present invention is applied. It is sectional drawing which shows the state in which this feed screw type tensioner apparatus was attached to the chain case. It is a rear view of this feed screw type tensioner device. It is a front view of this feed screw type tensioner device. It is an exploded sectional view of this feed screw type tensioner device. FIG. 6 is a view taken in the direction of arrow VI in FIG. 5. It is the VII-VII sectional view taken on the line of FIG. It is a front view of a cylinder. It is a front view of a guide member. It is an expansion perspective view of the rotating shaft body which concerns on a 1st modification. It is an expansion perspective view of the rotating shaft body which concerns on a 2nd modification. It is the elements on larger scale of the rotating shaft body. It is an expansion perspective view of the rotating shaft body which concerns on a 3rd modification.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
The feed screw tensioner device 20 according to the present embodiment is a cam chain that always applies tension to the cam chain 12 that transmits power from the crankshaft 6 of the SOHC type 4-stroke internal combustion engine 1 with the cylinder upright to the upper camshaft 11. Used as a tensioner.
The internal combustion engine 1 is mounted on a vehicle, and in the present specification, the front-rear and left-right directions are in accordance with a normal vehicle standard with the straight direction of the vehicle on which the internal combustion engine 1 is mounted as the front.

FIG. 1 is a longitudinal sectional view of a main part of the internal combustion engine 1.
A cylinder block 3 and a cylinder head 4 are sequentially stacked and united on a crankcase 2 that supports the crankshaft 6, and a cylinder head cover 5 is covered on the cylinder head 4.
The cylinder of the cylinder block 3 has a standing posture slightly tilted forward.

The cylinder head 4 is provided with a valve mechanism 10 that is driven by the rotation of the camshaft 11.
The camshaft 11 rotatably supported by the cylinder head 4 is disposed above the crankshaft 6 in parallel with the crankshaft 6, and the drive sprocket 6 s is fitted to the left end of the crankshaft 6. On the other hand, a driven sprocket 11s is fitted to the left end of the camshaft 11, and a cam chain 12, which is an endless transmission band, is bridged between the driving sprocket 6s and the driven sprocket 11s.

A chain guide 13 that is slightly curved and extends to the front long part of the front and rear long parts extending vertically above and below the cam chain 12 spanned between the drive sprocket 6s and the driven sprocket 11s guides. On the other hand, the other rear elongated portion is configured such that a tension slipper 14 curved in an arcuate shape is pressed from behind.
The tension slipper 14 is pivotally supported at the lower end thereof by the support shaft 15 in the vicinity of the crankshaft 6 and the portion extending upward is swingable back and forth.

  The cam chain 12, the chain guide 13, and the tension slipper 14 pass through the cam chain chamber 16 of the cylinder block 3, and after the chain case 3 c, which is a rectangular transmission band case forming the cam chain chamber 16. The feed screw tensioner device 20 is attached to the wall 3cr.

  The tensioner housing 21 of the feed screw tensioner device 20 has a bottomed cylindrical shape by a bottom wall 22 and a cylindrical wall 23, and the bottom wall 22 extends in a flange shape from the cylindrical wall 23 in the outer peripheral direction, particularly a pair of symmetrical portions. Is further extended to form a diamond-shaped flange portion 22f, and bolt mounting holes 22fh and 22fh are formed in symmetrically extending portions of the flange portion 22f (see FIGS. 3 and 4).

  A circular hole 3ch substantially equal to the outer diameter of the cylindrical wall 23 of the tensioner housing 21 is formed in the rear wall 3cr of the chain case 3c of the cylinder block 3 to attach the feed screw type tensioner device 20 to the chain case 3c. The flange portion 22f is applied to the rear wall 3cr through the seal member 71 so that the cylindrical wall 23 of the tensioner housing 21 is inserted into the circular hole 3ch of the rear wall 3cr from the outside of the rear wall 3cr of the chain case 3c. The feed screw tensioner device 20 is attached to the holes 22fh and 22fh through bolts 70 and 70 and screwed to the rear wall 3cr of the chain case 3c.

As shown in FIG. 1, the tensioner housing 21 of the feed screw tensioner device 20 is attached to the rear wall 3cr of the chain case 3c so that the central axis X of the cylindrical wall 23 is slightly inclined but is oriented substantially horizontally.
In the feed screw type tensioner device 20 attached to the rear wall 3cr of the chain case 3c, the pressing body 31 protrudes forward on the central axis X from the cylindrical wall 23 of the tensioner housing 21 to press the tension slipper 14, and the cam chain Apply tension to 12

The structure of the feed screw tensioner device 20 will be described in detail below.
As described above, the tensioner housing 21 includes the bottom wall 22 having the flange portion 22f and the cylindrical wall 23. The screw hole 22a is formed in the center of the bottom wall 22, and the rear end opening of the screw hole 22a is opened. At the edge, six locking grooves 22k are formed in the radial direction at equal intervals in the circumferential direction, and an annular recess 22r is formed on the outer periphery thereof (see FIGS. 3, 5, and 7).
An O-ring 51 is interposed in the annular recess 22r, and a seal bolt 50 with a flange is screwed into the screw hole 22a to close it (see FIGS. 2 and 5).

A circular bearing recess 22d is formed in the opening edge of the front end of the screw hole 22a at the center of the bottom wall 22.
A cup washer 40, which is a bearing member, is fitted into the bearing recess 22d.
The cup washer 40 is a flat cylindrical bowl-shaped thrust bearing member having a hollow bottom wall, the outer diameter is equal to the inner diameter of the bearing recess 22d, and the axial width is the same as the depth of the bearing recess 22d. The entire washer 40 fits into the bearing recess 22d (see FIGS. 2, 5, and 7).

An iron cup washer 40 is interposed in order to prevent the bearing recess 22d of the aluminum tensioner housing 21 from directly wearing a rotary shaft body 30, which will be described later, so that it can rotate freely.
The circular hole 40a in the center of the bottom wall of the cup washer 40 has substantially the same diameter as the screw hole 22a in the center of the bottom wall 22 of the tensioner housing 21.
A plurality of notches 41 are formed in the circumferential direction in the opening edge of the cup washer 40 (see FIGS. 5 and 6).

The tensioner housing 21 has a cylindrical wall 23 projecting forward from the bottom wall 22, and the cylindrical wall 23 decreases in thickness from the base end of the bottom wall 22 toward the tip opening edge, and the cross-sectional shape tapers. Is formed.
That is, the outer peripheral surface of the cylindrical wall 23 is formed with a conical surface so that the outer diameter decreases from the bottom wall 22 side toward the tip opening edge, and the inner peripheral surface of the cylindrical wall 23 extends from the bottom wall 22 side. A conical surface is formed so that the inner diameter increases toward the opening edge of the tip.

A plurality of oil guide grooves 24 and 25 that are substantially oriented (slightly inclined) in the axial direction of the central axis X are formed in the circumferential direction on the outer peripheral surface and the inner peripheral surface forming the conical surface of the cylindrical wall 23.
The oil guide grooves 24 and 25 form a continuous wave shape over the entire circumference arranged in a plurality of adjacent directions in the circumferential direction of the cylindrical wall 23.
The oil guide groove 25 on the inner peripheral surface of the cylindrical wall 23 extends to the bottom surface of the bottom wall 22 (see FIGS. 5 and 7).

A plurality of oil guide grooves 26 are formed in the radial direction from the central axis X on the annular bottom surface of the bottom wall 22 inside the cylindrical wall 23 and outside the bearing recess 22d (see FIG. 6).
The oil guide groove 26 on the bottom surface communicates with the oil guide groove 25 on the inner peripheral surface of the cylindrical wall 23 and also communicates with a notch 41 formed at the opening edge of the cup washer 40 fitted into the bearing recess 22d. (See FIG. 2).
The oil guide groove 26 on the bottom surface is formed deeper than the oil guide grooves 24 and 25 of the cylindrical wall 23.

Four wide engaging recesses 23k are formed at equal intervals in the circumferential direction on the edge of the opening of the cylindrical wall 23 (see FIGS. 5 and 6).
In the cylindrical wall 23, slit grooves 27 cut in the axial direction from the opening edge of the tip to the bearing recess 22d of the bottom wall 22 are respectively formed between the adjacent engagement recesses 23k and 23k (FIG. 5). FIG. 7).
The slit groove 27 is cut deeper than the bottom surface of the bearing recess 22d of the bottom wall 22 (see FIG. 7).

A part of the cylindrical wall 23 along the bottom wall 22 is perforated to form a locking hole 23e.
An outer end 45a of a spring spring 45 described later is locked in the locking hole 23e.
In addition, an outer peripheral groove 23c is formed on the outer peripheral surface of the opening end at the tip of the cylindrical wall 23 over the entire circumferential direction at a predetermined position ahead of the bottom surface of the engaging recess 23k in the axial direction.
A retaining ring 46 described later is fitted into the outer circumferential groove 23c from the outside.

  In the inside of the cylindrical wall 23 of the tensioner housing 21, a rotating shaft is rotatably supported at one end by a bearing recess 22 d formed on the center axis X of the cylindrical wall 23 and at the center of the bottom surface of the bottom wall 22. A pressing body 31 is provided that presses the cam chain 12 by advancing and retreating on the central axis X of the cylindrical wall 23 by screwing and rotating relative to the body 30 and the rotating shaft body 30. .

Referring to FIG. 5, the rotating shaft body 30 has a cylindrical shape, and in order from the front end side (front end side), a male screw portion 30 a, a screw base end portion 30 b, an extending portion 30 c, and a support shaft portion 30 d are provided. It is continuously formed on the same axis.
The male screw portion 30a is formed to be the longest, the extending portion 30c has a cylindrical shape whose outer diameter is slightly larger than that of the male screw portion 30a, and the support shaft portion 30d has an outer diameter larger than the extending portion 30c and is axially wide. A narrow flat cylindrical shape is formed, which is a flat cylindrical shape that is slightly smaller than the bearing recess 22 d of the bottom wall 22 of the tensioner housing 21.

The support shaft portion 30d and the extension portion 30c of the rotary shaft body 30 have slit locking holes extending from the rear end shaft end surface 30f forming the circular shape of the support shaft portion 30d to the extension portion 30c along the plane including the central axis. 30e is formed by cutting deeply.
As shown in FIG. 2, a spiral spring 45 wound in a spiral shape is disposed around the extending portion 30c of the rotating shaft 30, and the spring spring 45 is provided in the slit locking hole 30e of the extending portion 30c. The inner end portion 45b is locked.
The outer end 45a of the mainspring spring 45 is locked in the locking hole 23e of the cylindrical wall 23 of the tensioner housing 21 as described above (see FIG. 2).

The pressing body 31 includes a cylindrical body 32 and a cap 33 that is caulked and coupled to the tip thereof.
Referring to FIGS. 5 and 8, the cylindrical body 32 is provided with an internal thread 32a which is screwed into the external thread part 30a of the rotary shaft body 30 on the inner peripheral surface, and the outer peripheral surface of the cylindrical body 32 is a circumferential surface. Corresponding surfaces are flattened to form a pair of parallel flat surfaces 32b and 32b, and the cross-section has a deformed ellipse shape.
It should be noted that the rear end of the cylinder 32 is left flat without leaving a flat surface.

The cylindrical body 32 is supported so that the guide member 35 can freely rotate in the axial direction while restricting rotation.
With reference to FIGS. 5 and 9, the guide member 35 has a dish shape, and has a deformed ellipse-shaped insertion hole 35a equal to the cross-sectional shape of the cylindrical body 32 at the center, and a cross-section at the peripheral portion. The engaging claws 35k protrude in the radial direction.

  The four engaging claws 35 k of the guide member 35 are engaged with four engaging recesses 23 k formed at the opening edge of the cylindrical wall 23 of the tensioner housing 21, and the C-shaped retaining ring 46 is attached to the outer periphery of the cylindrical wall 23. By fitting in the groove 23c, the movement of the guide member 35 in the axial direction is restricted to prevent the dropout (see FIG. 2).

  As shown in FIG. 2, with the rotating shaft 30 and the cylinder 32 of the pressing body 31 screwed together, the rear end of one rotating shaft 30 is cupped on the bearing recess 22 d of the bottom wall 22 of the tensioner housing 21. The other cylindrical body 32 is supported through the washer 40 so as to be freely rotatable, and the other cylinder 32 penetrates the insertion hole 35a of the guide member 35 so that its rotation is restricted and the movement in the axial direction is freely supported.

  A hollow disc-shaped washer 47 is in contact with the side surface of the extending portion 30c from the front at the position of the screw base end portion 30b of the rotating shaft 30, and a cylindrical collar member 48 is interposed between the washer 47 and the guide member 35. It is interposed and positions the axial direction position of the guide member 35.

The assembly procedure of the feed screw tensioner device 20 having such a structure will be briefly described below with reference to FIG.
First, the mainspring spring 45 is inserted into the cylindrical wall 23 of the tensioner housing 21 with the cup washer 40 fitted in the bearing recess 22 d of the bottom wall 22 of the tensioner housing 21.
The spiral spring 45 has an outermost layer portion in contact with an inner peripheral surface near the bottom surface of the cylindrical wall 23, and an outer end portion 45a extending outward from the outermost layer portion is locked in a locking hole 23e of the cylindrical wall 23.

In this state, most of the spring 45 is wound around the outermost layer portion from the inside, the center portion is vacant, and the inner end 45b extends to the center of the hollow portion.
The rotating shaft body 30 is inserted into the cylindrical wall 23, and the extending portion 30c and the supporting shaft portion 30d of the rotating shaft body 30 are inserted into the hollow portion of the mainspring spring 45. At this time, the extending portion 30c and the supporting shaft portion are inserted. The inner end portion 45b of the mainspring spring 45 is inserted into the slit locking hole 30e formed in 30d and locked, and the support shaft portion 30d is inserted into the cup washer 40 of the bearing recess 22d so as to be supported. To.

  Here, the mainspring 45 is wound by rotating the rotary shaft 30 supported by the cup washer 40. When the mainspring 45 is fully wound, the screw hole 22a of the bottom wall 22 is externally attached by one leg and both arms. A T-shaped stopper locking piece 60 (indicated by a two-dot chain line in FIG. 3) is inserted to lock the tip of one leg to the slit locking hole 30e and to the outer opening edge of the screw hole 22a. By locking both arms in the locking grooves 22k, 22k at the symmetrical positions of the formed locking groove 22k, the rotation of the rotary shaft body 30 by the mainspring spring 45 is prohibited.

In this state, the washer 47 and the cylindrical collar member 48 are inserted into the cylindrical wall 23 through the rotary shaft 30, and then the cylindrical body 32 of the pressing body 31 is screwed into the male screw portion 30 a of the rotary shaft 30.
The screwing amount is set to an initial setting amount.

  Then, the guide member 35 is inserted into the deformed oval insertion hole 35a through the cylindrical body 32, and the four engagement claws 35k are formed at the four engagement recesses formed at the end opening edge of the cylindrical wall 23 of the tensioner housing 21. The C-shaped retaining ring 46 is engaged with the outer peripheral groove 23c of the cylindrical wall 23, and the guide member 35 is attached by restricting movement in the axial direction.

A pressing body 31 is integrated by caulking and coupling a cap 33 to the tip of the cylindrical body 32.
The rear end support shaft portion 30d of the rotary shaft body 30 is rotatably supported by the cup washer 40 of the bearing recess 22d of the bottom wall 22, and the pressing body 31 protrudes forward from the insertion hole 35a of the guide member 35, It is supported by the guide member 35 so as to be movable back and forth in the axial direction.

  The feed screw tensioner device 20 assembled as described above has the cylindrical wall 23 in the circular hole 3ch on the rear wall 3cr of the chain case 3c of the cylinder block 3 with the stopper locking piece 60 attached. The flange portion 22f is applied to the rear wall 3cr through the seal member 71 so as to be inserted, and is screwed and attached to the rear wall 3cr of the chain case 3c through the bolts 70 and 70 in the bolt mounting holes 22fh and 22fh (FIG. 1, FIG. 1). (See FIG. 2).

The screwing amount of the pressing body 31 with respect to the rotating shaft 30 is set optimally, and the cap 33 of the pressing body 31 is in contact with the tension slipper 14 at the initial setting position.
Here, when the stopper locking piece 60 is removed, the spring force of the spiral spring 45 that has been wound is applied to the rotating shaft body 30, and the rotating shaft body 30 is rotated so that the pressing screwed into the rotating shaft body 30 is engaged. The body 31 is advanced and the cam chain 12 is pressed through the tension slipper 14 to apply tension to the cam chain 12.

The screw hole 22a of the bottom wall 22 from which the stopper locking piece 60 has been removed is closed by screwing a seal bolt 50 with a flange through an O-ring 51.
The feed screw tensioner device 20 attached in this way is engaged with the rotary shaft body 30 urged by the mainspring spring 45, so that it does not move backward and the cam chain 12 is loosened. The cam shaft 12 can always be tensioned by rotating the rotary shaft 30 by the spring force of the mainspring spring 45 to advance the pressing body 31.

FIG. 2 is a sectional view showing a state in which the feed screw tensioner device 20 is attached to the rear wall 3cr of the chain case 3c of the cylinder block 3.
Oil scattered by the rotation of the cam chain 12 adheres to the inner wall surface of the chain case 3c of the cylinder head 4 and the cylinder block 3, and adheres to the inner surface of the rear wall 3cr of the chain case 3c as shown in FIG. The oil which flows down flows down to the upper outer peripheral surface of the cylindrical wall 23 of the tensioner housing 21 of the feed screw tensioner device 20 protruding inward from the rear wall 3cr.

The outer peripheral surface of the cylindrical wall 23 is formed with a conical surface so that the outer diameter decreases from the bottom wall 22 side toward the tip opening edge, and the upper portion is inclined so as to become lower toward the tip. Since the guide grooves 24 are arranged side by side in the circumferential direction of the cylindrical wall 23 to form a continuous wave shape, the oil that has flowed down to the upper outer peripheral surface of the cylindrical wall 23 of the tensioner housing 21 flows into the oil guide groove 24. It is guided and goes around the engaging recess 23k or the tip opening edge of the cylindrical wall 23 and enters the inner peripheral surface side of the cylindrical wall 23.
As shown in FIG. 2, the guide member 35 is positioned by the cylindrical collar member 48 and has a gap between the bottom surface of the engagement recess 23k and the engagement claw 35k of the guide member 35, and the oil is cylindrical. The wall 23 can go around the inner surface.

  The inner peripheral surface of the cylindrical wall 23 is formed with a conical surface formed so that the inner diameter increases from the bottom wall side toward the edge of the tip opening, and the upper portion is inclined so as to become lower toward the bottom wall 22 side. In addition, the oil guide grooves 25 are arranged in a plurality of adjacent directions in the circumferential direction of the cylindrical wall 23 so as to form a continuous wave shape up to the bottom surface of the bottom wall 22. The oil that has entered is urged toward the bottom wall 22 and travels along the oil guide groove 25 to the bottom wall 22, and the oil guide is formed on the bottom surface of the bottom wall 22 in the radial direction from the axial center. Guided by the groove 26 and collected in the cup washer 40 of the central bearing recess 22d.

  The opening edge of the cup washer 40 is formed with a plurality of cutouts 41 in the circumferential direction, so that the oil collected in the cup washer 40 is cut out at the bearing portion of the rotary shaft 30 inside the cup washer 40. Oil can be smoothly supplied through 41.

  The bearing of the rotating shaft body 30 by the cup washer 40 supports both radial load and thrust load, but especially the axial thrust load of the rotating shaft body 30 that receives the tension of the cam chain 12 acts on the rotating shaft body. It is important to supply oil to the thrust bearing portion where the 30 shaft end face 30f and the bottom face of the cup washer 40 abut.

  Since the oil guide groove 26 on the bottom surface of the bottom wall 22 is dug deeper than the oil guide grooves 24 and 25 of the cylindrical wall 23, oil can be stored on the bottom surface of the bottom wall 22, so that the rotating shaft body Oil can be stably supplied to 30 thrust bearing parts.

  In this way, the feed screw tensioner device 20 efficiently guides the oil that adheres and flows down to the inner wall surface of the chain case 3 c into the cylindrical wall 23 of the tensioner housing 21, and is sufficient for the bearing portion of the rotary shaft 30. It can be supplied to prevent wear.

  Since the oil passage is not formed in the wall of the tensioner housing 21, the structure is simple, and it is not necessary to design the oil supply passage on the chain case 3c side. Therefore, even when employed in the internal combustion engine, it is limited by the type of the internal combustion engine. Therefore, versatility can be maintained at a high level, and costs can be reduced.

  Referring to FIG. 6, in the feed screw tensioner device 20 of the present embodiment, one engagement recess 23 k out of four engagement recesses 23 k formed at the tip opening edge of the cylindrical wall 23 of the tensioner housing 21 is provided. Since it is attached to the chain case 3c so as to be directly above, the oil that has flowed to the upper outer peripheral surface of the cylindrical wall 23 of the tensioner housing 21 is oil in the circumferential width of the engaging recess 23k from above. The oil is guided to the oil guide groove 24 and flows around the bottom surface of the engaging recess 23k to the inner peripheral surface side of the cylindrical wall 23. The end surface of the opening of the cylindrical wall 23 flows around the inner peripheral surface of the cylindrical wall 23.

  A groove extending radially from the center of the shaft may be formed on the bottom surface of the engaging recess 23k and the end opening end surface of the cylindrical wall 23, and the inner circumferential surface side of the cylindrical wall 23 of oil is formed by the groove. It is possible to smoothly go around.

Since the cylindrical wall 23 has a slit groove 27 between the engagement recesses 23k and 23k, the bottom wall 22 extends from the opening edge on the left and right sides of the engagement recess 23k which is directly above the upper half of the cylindrical wall 23. There is a slit groove 27 cut in the axial direction up to the bearing recess 22d (see FIG. 6).
As described above, the oil that has been guided by the oil guide groove 24 to flow around the engaging recess 23k or the tip opening edge overflows to the left or right, or the oil that has flowed down to the position of the slit groove 27 enters the slit groove 27. The oil flows out from the slit groove 27 to the inner peripheral surface of the cylindrical wall 23 and can be directly supplied to the bearing concave portion 22d in which the slit groove 27 is cut, to the bearing portion of the cup washer 40 that bears the rotating shaft body 30. The oil supply amount can be increased.

  Since the wave shape formed by the oil guide grooves 24 and 25 is formed over the entire circumference of the cylindrical wall 23, the tensioner housing 21 is attached to the chain case 3c with the central axis X of the cylindrical wall 23 being substantially horizontal. In addition, the oil guide grooves 24 and 25 can always be positioned on the outer peripheral surface and the inner peripheral surface on the upper side regardless of the mounting angle of the cylindrical wall 23. It has improved.

The tensioner housing 21 is molded by a mold that is divided into two in the axial direction of the central axis X of the cylindrical wall 23, so that oil guide grooves 24 and 25 that are substantially oriented in the axial direction can be simultaneously molded by the mold. In addition, the cylindrical wall 23 formed in a tapered shape by the outer peripheral surface and the inner peripheral surface forming a conical surface can be easily punched and molded in the axial direction.
Note that the present invention is not limited to the embodiment described herein, and for example, the oil guide grooves 24 and 25 may be configured by a single groove.

Next, as another embodiment, a modified example of the rotating shaft body 30 whose one end is pivotally supported by the cup washer 40 fitted in the bearing recess 22d of the tensioner housing 21 will be described with reference to FIGS. .
The other parts excluding the rotating shaft body are the same as the parts of the feed screw tensioner device 20 of the above-described embodiment, and the rotating shaft body has the same shape except for the shaft end face. Parts and members will be described using the same reference numerals.

In FIG. 10, the 1st modification of the rotating shaft 30 is shown.
A support shaft portion 30d which is a shaft end portion of the rotary shaft body 30 is inserted into the cup washer 40 to be subjected to radial bearing and thrust bearing.
Since the axial thrust load of the rotary shaft body 30 receiving the tension of the cam chain 12 is large, the cup washer 40 has a particularly large function as a thrust bearing.

A shaft end surface 30f facing and contacting the bottom surface of the cup washer 40 of the support shaft portion 30d of the rotating shaft body 30 forms a circular plane, and a chamfered portion 30g having a chamfered peripheral edge is formed.
A slit locking hole 30e for locking the inner end 45b of the mainspring spring 45 is formed in the shaft end 30d of the rotary shaft 30 by cutting along the axis center from the shaft end surface 30f. The circular plane is divided into two semicircles by the slit locking holes 30e.
The shaft end surface 30f of the support shaft portion 30d of the rotating shaft body 30 is formed to have a surface roughness such that the maximum height roughness Rz defined in JIS B601: 2001 is 7 or more and 26 or less.

As described above, the oil that adheres to the inner surface of the rear wall 3cr of the chain case 3c and flows down from the outer peripheral surface of the cylindrical wall 23 of the tensioner housing 21 to the inner peripheral surface and enters the cup washer 40 of the central bearing recess 22d. The collected parts enter the bearing part of the rotary shaft 30 inside the cup washer 40 to lubricate the bearing part.
The oil collected in the cup washer 40 first enters the journal bearing portion on the outer periphery of the support shaft portion 30 d of the rotating shaft body 30, and then the thrust bearing portion where the shaft end surface 30 f of the rotating shaft body 30 contacts the bottom surface of the cup washer 40. To.
The oil guided to the thrust bearing portion is sufficiently held on the uneven surface having the same surface roughness of the shaft end surface 30f having the surface roughness such that the maximum height roughness Rz is 7 or more and 26 or less.

As described above, since the shaft end surface 30f of the rotating shaft body 30 is thrust bearing in contact with the bottom surface of the cup washer 40 in a state where the oil is sufficiently held, the rotational resistance generated by the relative rotation of the rotating shaft body 30 with respect to the cup washer 40 is reduced. The increase due to the surface roughness of the shaft end surface 30f of the rotary shaft body 30 is sufficiently held by the uneven surface having a surface roughness such that the maximum height roughness Rz of the shaft end surface 30f is 7 or more and 26 or less. It is possible to suppress thrust by lubrication with oil and maintain an appropriate rotational resistance to perform a thrust bearing, and it is possible to operate the feed screw mechanism more reliably.
Further, wear in the thrust bearing can be suppressed by the sufficiently retained oil.

When the maximum height roughness Rz of the shaft end face 30f of the rotary shaft 30 is smaller than 7, the resistance in the relative rotation of the rotary shaft 30 with respect to the cup washer 40 is originally small so that an appropriate rotational resistance can be obtained with oil. However, oil retention is also reduced.
When the maximum height roughness Rz is larger than 26, the resistance in the relative rotation of the rotating shaft body 30 with respect to the cup washer 40 is originally too large, and an appropriate rotational resistance can be obtained even if sufficient oil is retained. Have difficulty.

Next, a second modification of the rotating shaft 30 will be described with reference to FIGS.
The shaft end surface 30f facing and contacting the bottom surface of the cup washer 40 of the support shaft portion 30d of the rotating shaft body 30 is divided into two semicircles by a slit locking hole 30e, as in the first modification. A chamfered portion 30g having a chamfered peripheral edge is formed.

An oil groove 30v is formed in the shaft end surface 30f of the support shaft portion 30d of the rotary shaft body 30 along the outer peripheral edge 30fe on the inner side of the outer peripheral edge 30fe of the coaxial end surface 30f.
The oil groove 30v of the shaft end face 30f is divided by the slit locking holes 30e and further divided in the circumferential direction, and finally divided into four, and the divided oil grooves 30v have the same arc shape. The arc-shaped oil grooves 30v having the same shape are formed at substantially equal intervals in the circumferential direction.

Each arc-shaped oil groove 30v is formed along the outer peripheral edge 30fe inside the outer peripheral edge 30fe of the shaft end surface 30f of the rotary shaft 30, and the end of the arc-shaped oil groove 30v on the slit locking hole 30e side is slit. Since it is formed away from the locking hole 30e, the arcuate oil groove 30v is formed on the shaft end surface 30f independently from the chamfered portion 30g and away from the slit locking hole 30e.
Therefore, oil tends to accumulate in each arcuate oil groove 30v.
The four arc-shaped oil grooves 30v in which the oil easily collects are evenly arranged in the circumferential direction on the shaft end surface 30f of the rotating shaft 30, so that the oil is well balanced over the entire surface of the shaft end surface 30f of the rotating shaft 30. Can be dispersed and held.

Therefore, the shaft end surface 30f of the rotary shaft 30 is in contact with the bottom surface of the cup washer 40 in a state where the oil is appropriately held in a balanced manner on the surface by the four arc-shaped oil grooves 30v and is thrust-bearing.
That is, in the relative rotation of the rotating shaft 30 with respect to the cup washer 40, the oil is held on the shaft end surface 30f in a balanced and appropriate manner so that a thrust bearing can be maintained while maintaining an appropriate rotational resistance. It is possible to operate more reliably and to suppress wear in the thrust bearing.

As described above, the rotary shaft body 30 of the second modified example has four arcuate oil grooves 30v formed on the shaft end face 30f. However, the present invention is not limited to this, and for example, shown in FIG. As in the third modification, the arcuate oil groove 30v formed in one shaft end surface 30f divided by the slit locking hole 30e of the rotating shaft 30 is divided into arcuate shapes in the second modification. The oil groove 30v is communicated to form one arcuate oil groove 30v.
Accordingly, the rotary shaft body 30 of the third modification example has three arcuate oil grooves 30v formed on the shaft end face 30f, and can achieve the same effects as those of the second modification example.

Furthermore, the shaft end surface 30f of the rotating shaft 30 may be processed to a required surface roughness, and an oil groove may be formed in the shaft end surface 30f processed to the required surface roughness.
The feed screw tensioner device according to the present invention has been described above. However, the aspect of the present invention is not limited to the above-described embodiment, and includes those implemented in various aspects within the scope of the gist of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Crank case, 3 ... Cylinder block, 3c ... Chain case, 4 ... Cylinder head, 5 ... Cylinder head cover, 6 ... Crankshaft,
10 ... Valve mechanism, 11 ... Cam shaft, 12 ... Cam chain, 13 ... Chain guide, 14 ... Tension slipper, 15 ... Support shaft, 16 ... Cam chain chamber,
20 ... lead screw type tensioner device, 21 ... tensioner housing, 22 ... bottom wall, 22d ... bearing recess, 23 ... cylindrical wall, 23k ... engagement recess, 24 ... oil guide groove, 25 ... oil guide groove, 26 ... oil guide Groove, 27 ... Slit groove,
30 ... Rotating shaft body, 30a ... Male screw portion, 30b ... Screw base end portion, 30c ... Extension portion, 30d ... Support shaft portion, 30e ... Slit locking hole, 30f ... Shaft end surface, 30g ... Chamfering portion, 30v ... ( Arc shape) oil groove,
31 ... Pressing body, 32 ... Cylinder, 33 ... Cap, 34 ..., 35 ... Guide member, insertion hole 35a ... insertion hole, 35k ... engaging claw,
40 ... cup washer, 41 ... notch, 45 ... spring spring, 46 ... retaining ring, 47 ... washer, 48 ... cylindrical collar member, 50 ... seal bolt, 51 ... O-ring, 60 ... stopper locking piece.

Claims (14)

A tensioner housing (21) which has a bottomed cylindrical shape by a bottom wall (22) and a cylindrical wall (23) and is attached to the transmission band case (3c) with the central axis (X) of the cylindrical wall (23) oriented substantially horizontally. )When,
A rotating shaft body (30) rotatably supported at one end in a bearing recess (22d) formed at the center of the bottom surface of the bottom wall (22),
The rotation is restricted by a guide member (35) provided in the opening of the cylindrical wall (23) by screwing with the rotary shaft (30) and on the central axis (X) of the cylindrical wall (23). A pressing body (31) that is pivotally supported, and advances and retreats in the axial direction by rotation of the rotating shaft body (30), and a torsion spring (45) that biases the rotating shaft body (30) in one rotation direction. With
In the feed screw type tensioner device that constantly applies tension to the endless transmission band (12) by pressing the endless transmission band (12) for transmitting power by the advancement of the pressing body (31),
Oil guide grooves (24, 24) substantially oriented in the axial direction at least on the outer peripheral surface and inner peripheral surface of the upper half of the cylindrical wall (23) of the tensioner housing (21) attached to the transmission band case (3c). 25) A feed screw tensioner device, characterized in that it is formed.   The feed screw tensioner device according to claim 1, wherein the oil guide grooves (24, 25) are arranged in a plurality of adjacent directions in the circumferential direction of the cylindrical wall (23) to form a continuous wave shape.   The lead screw type tensioner device according to claim 2, wherein the wave shape formed by the oil guide groove (24, 25) is formed over the entire circumference of the cylindrical wall (23).   The oil guide groove (25) on the inner peripheral surface of the cylindrical wall (23) extends to the bottom surface of the bottom wall (22). Lead screw type tensioner device.   The feed screw according to any one of claims 1 to 4, wherein a plurality of grooves (26) directed radially from an axial center are formed on a bottom surface of the bottom wall (22). Tensioner device.   At least the upper half of the cylindrical wall (23) is formed with a slit groove (27) cut in the axial direction from the edge of the opening at the front end to the bearing recess (22d) of the bottom wall (22). The feed screw type tensioner device according to any one of claims 1 to 5. The outer peripheral surface of the cylindrical wall (23) is formed with a conical surface so that the outer diameter decreases from the bottom wall (22) side toward the tip opening edge,
The inner circumferential surface of the cylindrical wall (23) is formed with a conical surface so that an inner diameter increases from the bottom wall (22) side toward a tip opening edge. A feed screw type tensioner device according to any one of the above.   The feed screw type tensioner device according to claim 7, wherein the tensioner housing (21) is formed by a die divided into two in the axial direction of the central axis (X) of the cylindrical wall (23). One end of the rotary shaft body (30) is rotatably supported via a bowl-shaped bearing member (40) fitted to the bearing recess (22d) of the bottom wall (22),
The feed screw tensioner according to any one of claims 1 to 8, wherein a plurality of notches (41) are formed in a circumferential direction at an opening edge of the flange-shaped bearing member (40). apparatus.   A shaft end surface (30f) facing and contacting the bottom surface of the hook-shaped bearing member (40) at the shaft end portion (30d) of the rotary shaft body (30) rotatably thrust-bearing on the hook-shaped bearing member (40). The feed screw tensioner device according to claim 9, wherein the lead screw type tensioner device is formed to have a required surface roughness.   11. The shaft end surface (30f) of the rotary shaft (30) is processed and formed to have a surface roughness such that the maximum height roughness Rz is 7 or more and 26 or less. Lead screw type tensioner device.   A shaft end surface (30f) facing and contacting the bottom surface of the hook-shaped bearing member (40) at the shaft end portion (30d) of the rotary shaft body (30) rotatably thrust-bearing on the hook-shaped bearing member (40). 11. The feed according to claim 9, wherein an oil groove (30v) is formed along the outer peripheral edge (30fe) inside the outer peripheral edge (30fe) of the coaxial end surface (30f). Screw type tensioner device.   The feed screw type tensioner device according to claim 12, wherein the oil groove (30v) includes a plurality of arcuate oil grooves (30v) divided in a circumferential direction. A slit locking hole (30e) for locking one end of the torsion spring (45) is cut in the shaft end portion (30d) of the rotating shaft body (30) from the shaft end surface (30f) along the axis center. Formed with
The feed screw type tensioner device according to claim 13, wherein the arcuate oil groove (30v) is formed apart from the slit locking hole (30e).

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