JPH035703Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a belt tensioning system that is applied to an engine that has a recess in the side wall of the engine body on the side where the timing belt is disposed so as to intersect with the timing belt. Regarding the Yona device.

(Prior Art) Conventionally, a tension pulley is pivotally supported on the outer surface of a rocking plate pivotally attached to the side wall of an engine body, and
A tensioner, in which a plunger is assembled to a cylinder so as to be urged forward in the axial direction of the cylinder by a biasing mechanism within the cylinder, is fixed to the outer side wall portion of the timing belt in the cylinder, and the plunger is attached to the cylinder. It is known that the tension pulley is brought into pressure contact with the timing belt via the swing plate by the urging force of the plunger, which is brought into contact with the swing plate from the outside.
(see publication).

(Problems to be solved by the invention) In the above method, in the process of assembling the belt tensioner device to the engine, it is necessary to assemble the rocking plate and the tensioner separately to the engine body, which reduces productivity. In addition, it is necessary to secure a space for arranging the tensioner on the outer side wall of the timing belt, which makes it impossible to effectively use the side wall as space for auxiliary equipment, resulting in poor space efficiency. descend.

By the way, recently, in order to make engines smaller and lighter, the oil pump and water pump housings are integrally attached to the side wall of the engine body, and the timing belt is wrapped not only around the cam pulley but also around the pump pulley on the outside of these housings. , engines in which the camshaft and these pumps can be driven by the same belt have become mainstream.
In this case, a recess is formed between these housings in the side wall portion in a positional relationship that intersects the timing belt.

This recess was originally a dead space,
It is desirable to utilize this in the above-mentioned tensioner arrangement space to improve space efficiency, and furthermore, to make it possible to assemble the rocking plate and tensioner into the engine body as a single assembly.
It is desirable to improve productivity.

An object of the present invention is to provide a tensioner device that meets such demands.

(Means for Solving the Problems) In order to achieve the above object, the present invention is mounted on an engine that has a recess in the side wall of the engine body on the side where the timing belt is located, the recess being positioned so as to intersect with the timing belt. A belt tensioner device in which a tension pulley is pivotally supported on the outer surface of a rocking plate pivotally connected to the side wall, and a plunger is attached to the cylinder in the axial direction of the cylinder by a biasing mechanism in the cylinder. A tensioner assembled so as to be biased by the timing belt is provided, and the tensioner is configured to press the tension pulley against the timing belt, and the cylinder of the tensioner is recessed into the recess. A stopper facing the plunger is provided protruding from the side wall so that the swing plate is fixed to the inner surface of the rocking plate so that the tension is fixed to the rocking plate. The present invention is characterized in that a moment is applied in a direction to press the timing belt into contact with the timing belt.

(Function) When assembling the tensioner device to the engine body, the tensioner is fixed in advance to the inner surface of the rocking plate in its cylinder, and the tensioner is recessed into the recess in the side wall of the engine body. It is aligned so that it is inserted into the oscillator plate, and is pivotally connected to the side wall portion on the swing plate.

In this state, if the plunger of the tensioner is brought into contact with the stopper of the side wall opposite to it, the contact reaction force acts on the rocking plate to which the plunger is fixed via the cylinder of the tensioner, and The moving plate receives a moment due to this contact reaction force and swings, and a tension pulley pivotally supported by the swinging plate comes into pressure contact with the timing belt, thereby applying a predetermined tension to the belt.

(Example) Referring to FIGS. 1 and 2, reference numeral 1 indicates an engine body mounted in a vehicle in a forward-inclined position, and a side wall portion 1a of the engine body 1 on the side where the timing belt is disposed.
, the oil pump housing 2 around the crankshaft.
and a water pump housing 3 between the housing 2 and the cylinder head 1b are integrally attached, and a crank pulley 4 is mounted on the outer surface of the oil pump housing 2 to be rotated counterclockwise in FIG. 1 by a crankshaft. A water pump pulley 5 was provided on the outer surface of the water pump housing 3, and a cam pulley 6 was provided on the outer surface of the cylinder head 1b, and a timing belt 7 was wound around these pulleys 4, 5, and 6.

In this case, both the housings 2 of the side wall portion 1a,
3, a recess 8 is formed in a positional relationship that intersects the timing belt 7.

A swinging plate 9 is pivotally attached to the side wall portion 1a, and a tension pulley 10 is pivotally supported on the outer surface of the swinging plate 9. The tension pulley 10 is swung inward toward the slack side portion of the upper side, that is, downward in the drawing, so as to press the tension pulley 10 against the slack side portion of the belt 7 from above.

To explain this in more detail, in the illustrated example, the rocking plate 9 is formed into a substantially triangular shape having a vertically elongated base that covers the recess 8, and has a cylinder at its apex as shown in the third figure. A protruding portion 9a is provided so that the cylindrical portion 9a is rotatably fitted to a pivot shaft 12 implanted in a portion of the oil pump housing 2 near the recess 8, and the outer surface of the upper end of the bottom portion Bearing holder 9
b is fixed with bolts, and the tension pulley 10 is pivotally supported on the outer periphery of the holder 9b via a bearing 9c. The pulley 10 is pressed against the timing belt 7 from above.

In the drawing, 12a is an oil groove on the outer periphery of the pivot shaft 12;
Reference numeral 2b indicates an oil seal, and reference numeral 13 indicates a mounting bolt with a washer 13a for securing the cylinder portion 9a to the pivot shaft 12.

As shown in FIG. 4, the tensioner 11 has a plunger 11b attached to the cylinder 11a.
The cylinder 11a is activated by the biasing mechanism 11c in the cylinder 1a.
The biasing mechanism 11c is assembled so as to be biased axially forward in the cylinder 11a, and a bolt 11e at the tip is fixedly supported in the axial direction by a stop ring 11d within the cylinder 11a. The plunger 11b is inserted into the irregularly shaped hole 11i formed in the cap 11h at the open end of the cylinder 11a as shown in the fifth figure. Insert the bolt 11e into the threaded hole at the tail end of the plunger 11b to prevent rotation.
When the rod 11f is rotated forward by the biasing force of the spring 11g, the plunger 11b is pushed forward. The cylinder 11a is connected to the operator 11j that tightens the cylinder 11a.
A locking pin 11k that engages with the rod 11f and prevents it from rotating is inserted into the outer periphery of the tail end of the rod 11f so as to be freely removable.
The spring 11g can be held in a tightened state by the pin 11k.

The cylinder 11a of the tensioner 11
The cylinder 11a is attached to the inner surface of the bottom of the rocking plate 9 so that the tensioner 11 is recessed into the recess 8 and the plunger 11b faces outward, that is, upward in the rocking direction of the rocking plate 9. 1 on both sides of the tail end
It is fixed by a pair of bolts 14, 14, and furthermore, an upper stopper 15, which faces the plunger 11b, is provided protruding from the side wall portion 1a.

Note that the tensioner 11 includes the plunger 11.
A bellows-shaped boot 11 liquid-tightly covers the outer periphery of the plunger 11b, and contains lubricating oil for lubricating the sliding and threaded parts of the plunger 11b. A breathing hole of 11 m was formed to communicate the interior with the atmosphere. In this case, if the plunger 11b is directed downward, lubricating oil will leak to the outside from the breather hole 11m, but since the plunger 11b is directed upward as described above, such a problem will not occur.

In the drawings, reference numeral 16 indicates an operation hole for the locking pin 11k formed in the swing plate 9, and reference numeral 17 indicates an escape hole formed in the swing plate 9 to receive the large diameter portion of the cylinder 11a.

When assembling the tensioner device to the engine body 1, the cylinder 1 of the tensioner 11 must be assembled in advance.
1a is fixed on the inner surface of the rocking plate 9, and the rod 11 is inserted by a screwdriver or the like via the operator 11j.
f is reversely wound to tighten the spring 11g, the rod 11f is prevented from rotating by the locking pin 11k, and then, in the assembly process, the tensioner 11 is recessed into the recess 8 and the rod 11f is tightened. What is necessary is to fit the cylindrical portion 9a of the rocking plate 9 onto the pivot shaft 12 and tighten the bolt 13.

After the timing belt 7 is wrapped, the locking pin 11k is pulled out through the operation hole 16, and according to this, the rod 11f is attached to the spring 11g.
The plunger 11b is pushed upward and comes into contact with the stopper 15, and the reaction force of this contact pushes the cylinder 11a downward, causing the cylinder 11a to rotate counterclockwise against the rocking plate 9 to which it is fixed. A moment acts, and the tension pulley 10 is pressed against the upper slack side portion of the belt 7 from above, and a predetermined tension is applied to the belt 7.

By the way, the cylinder 11a of the tensioner 11 is fixed in the recess 8 as shown in FIG.
1b may be brought into contact with the swing plate 9, but in this case, the plunger 11b pushes the swing plate 9 in a direction away from the timing belt 7, so the tension pulley 10 is moved away from the timing belt 7. 7, the swing plate 9 must be pressed against the pivot 1.
2, it is necessary to extend an arm portion extending in the opposite direction to the contact point of the plunger 11b and to pivotally support the tension pulley 10 on this arm portion, and the distance between the tension pulley 10 and the crank pulley 4 increases. , the winding length of the timing belt 7 around the crank pulley 4 is reduced, making it impossible to reliably prevent tooth skipping, and since the swing plate 9 is extended outside the timing belt 7, space efficiency can be improved to the left. It disappears.

In contrast, according to the embodiment described above, the tensioner 11 is recessed into the recess 8 near the crank pulley 4, and the tension pulley 10 can be pressed against the timing belt 7 near the crank pulley 4. does not occur.

(Effect of the invention) As described above, according to the invention, the tensioner device can be assembled by simply attaching the assembly consisting of the tensioner to the rocking plate to the side wall of the engine body on the rocking plate. Compared to conventional equipment that requires the tensioner and rocking plate to be individually assembled to the engine body, the assembly work is easier and productivity is improved, and the recess in the side wall is used as a space for installing the tensioner. This has the effect of making it possible to arrange the device compactly and improving space efficiency.

[Brief explanation of the drawing]

FIG. 1 is a side view of an example of an engine equipped with the device of the present invention, FIG. 2 is a bottom view taken from the line - in FIG. 1, and FIGS. 3 and 4 are the lines - and - in FIG. 1, respectively. FIG. 5 is an enlarged cross-sectional view taken along the line, FIG. 5 is a cross-sectional view taken along the line -- in FIG. 4, and FIG. 6 is a side view of a comparative example in which the tensioner is fixed in a recess. DESCRIPTION OF SYMBOLS 1... Engine body, 1a... Side wall part, 7... Timing belt, 8... Recess, 9... Rocking plate, 10... Tension pulley, 11... Tensioner, 11a... Cylinder, 11b... Plunger, 11c... Biasing mechanism,
15...Stotsupa.

Claims (1)

[Scope of utility model registration request] A belt tensioner device mounted on an engine that has a recess in a side wall of the engine body on the side where the timing belt is arranged, the recess being in a positional relationship that intersects the timing belt. Along with supporting the tension pulley on the side,
A tensioner is provided in the cylinder, in which a plunger is assembled so as to be urged forward in the axial direction of the cylinder by a biasing mechanism within the cylinder, and the tensioner is brought into pressure contact with the timing belt. The cylinder of the tensioner is fixed to the inner surface of the rocking plate so that the tensioner is recessed into the recess, and a stopper facing the plunger is provided protruding from the side wall, and the tensioner is recessed into the recess. A belt tensioner device for an engine, characterized in that a moment is applied to the rocking plate in the direction of pressing the tension pulley against the timing belt by a reaction force of the plunger against the stopper.