JPS61215844A - Tensioner apparatus in laying transmission apparatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To operate an autoadjustor efficiently by supplying the pressurized oil into a supplied-oil chamber and discharging the air in the oil in the supplied- oil chamber through an air vent passage. CONSTITUTION:A high-pressure oil chamber 31 and a supplied-oil chamber 32 are allowed to communicate through a valve port 33 formed onto a plunger 23. Further, a tension spring 34 for applying a prescribed tension onto the loosening side of a transmission belt 5 through a tensioner 8 by urging a check valve V and the plunger 23 in the extension direction is accommodated into the high-pressure chamber 31. Further, the discharge oil hole 49 of the supplied- oil chamber 32 is allowed to communicate to an oil sump 48, and an oil supplying hole 38 is allowed to communicate to a hydraulic pump P. Further a leak passage 51 is formed between the plunger 23 and a plunger case 21, and the oil feeding hole 38 is allowed to communicate to the oil discharge hole 49 through said leak passage 51. With such constitution, an autoadjustor can be operated efficiently.

Description

Detailed Description of the Invention A. Object of the Invention (1) Industrial Application Field The present invention relates to an endless transmission band suspended between a driving wheel and a driven wheel supported by an engine body in an internal combustion engine. The present invention relates to a tensioner device for a wrap-around transmission that automatically applies a constant tension.

(2) Conventional technology In conventional internal combustion engines, an endless transmission band is suspended between the driving wheels and driven wheels, and an auto-adjuster is connected to the tensioner body that is pressed into contact with the transmission band. A device that applies a tension of 1 is known (Japanese Utility Model Publication No. 57-202039).

(3) Problems to be Solved by the Invention In such oil-filled auto-adjusters, air mixed in the oil tends to get caught in the oil chamber as the plunger slides up and down, and this trapped air can be quickly and smoothly discharged. (There is a problem in that the number of bubbles generated in the oil chamber gradually increases, which may impede its operation.)

The present invention has been made in view of the above circumstances, and it is possible to continuously supply pressurized oil into the plunger case, thereby making it difficult for air to get trapped in the pond inside the case, and to prevent the air trapped therein. It is an object of the present invention to provide a tensioner device for a wrap transmission in an internal combustion engine, which can ensure efficient operation of an auto-adjuster by quickly and smoothly discharging it to the outside.

B1 Structure of the Invention (1) Means for Solving Problems According to the present invention, in order to achieve the above-mentioned object, an endless transmission belt is suspended between a driving pulley and a driven pulley supported by the engine body, and the transmission belt is In a tensioner device for a wrap transmission in an internal combustion engine, which applies a predetermined tension to the transmission belt by pressing a tensioner against the slack side of the belt, a plunger case is provided in the adjuster case fixed to the engine body, A plunger connected to the tensioner is slid onto the plunger case to form a high-pressure oil chamber in the lower part of the plunger case and a sealed replenishment oil chamber in the upper part thereof, and the high-pressure oil chamber and the replenishment oil chamber are formed in the plunger case. , communicates with the high pressure oil chamber through a valve port bored in the plunger, and
A check valve that closes the valve port when the pressure of the cough chamber increases and opens the valve port when the pressure decreases, and a tension spring that biases the plunger in the extension direction and applies a predetermined tension to the slack side via the tensioner. Furthermore, the replenishment oil chamber communicates its oil supply hole with the hydraulic pump and its oil drain hole with the oil reservoir of the engine body, and furthermore, forms a leak passage between the plunger and the plunger case, and the leak passage is connected to the hydraulic pump. The supply oil chamber is communicated with the oil drain hole through the oil supply hole.

(2) Function According to the above configuration, pressurized oil from the hydraulic pump is constantly supplied to the replenishment oil chamber in the plunger case, and the air trapped in the oil in the replenishment oil chamber flows through the air vent passage. and are actively removed.

(3) Embodiment A first embodiment in which the device of the present invention is applied to a DOHC four-stroke internal combustion engine will be described below with reference to FIGS. 1 to 6.

In FIG. 1, a timing winding transmission T is provided on one end surface of an engine body E of the internal combustion engine for interlocking a crankshaft 1 and a pair of valve operating camshafts 2 of a valve operating mechanism. This timing winding transmission device T has an endless transmission belt 5 suspended between a driving pulley 3 fixed to a crankshaft 1 and driven pulleys 4 fixed to a pair of valve drive camshafts 2, respectively. configured.

Another driven pulley 6 is suspended in the middle of the transmission belt 5, and a cooling water pump 7 of the engine body E is driven by this driven pulley 6.

In FIGS. 1 to 3, between the driving pulley 3 and the other driven pulley 6, on the outside of the loose side 51 of the transmission belt 5,
A tension pulley I78 is provided, and this tension pulley 8 is attached to a pulley shaft 1 protruding from the middle part of the swing lever 9.
0 through a ball bearing 11 so as to be rotatable. The base end of the swing lever 9 is supported by a support shaft 12 on an end wall 13 of the engine body E so as to be able to swing up and down. Lubrication type auto adjuster A is connected. The tension pulley 8 is pressed against the transmission belt 5 by the control force of the auto adjuster A, and a constant tension is applied to the belt 5.

Further, the other end side of a tension spring 14 whose base end is tied to the end wall 13 of the engine body E is connected to the upper part of the intermediate position of the swing lever 9, and the tension force of this tension spring 14 is as follows. The swing lever 9 is biased so as to swing counterclockwise around the support shaft 12, and the tension pulley 8 is biased so as to come into pressure contact with the outer surface of the loose side 51 of the transmission belt 5.

A conventionally known hydraulic pump P is fixed to the end wall 13 of the engine body E for forcibly supplying lubricating oil or the like to each lubricated part of the engine body E, and this hydraulic pump P is directly connected to the crankshaft 1. It is driven by Then, the reservoir in the engine body E is discharged from the suction passage Pi (FIG. 4) to the suction and discharge passage Po.

On the outer surface of the pump case 16 of the hydraulic pump P, an adjuster case 17 of the oil supply type auto adjuster A is integrally cast.

Next, we will mainly explain the structure of this oil-filled auto adjuster A in Section 5.
Referring to FIG. 6, the adjuster case 17 of the auto adjuster A is integrally formed on the upper outer surface of the pump case 16. A hollow cylindrical housing 19 having an open upper end 18 is formed in the adjuster case 17 . A hollow cylindrical plunger case 21 having an open upper end 20 is fitted into the housing 19.
The upper outer periphery of the plunger case 21 and the housing 19
An O-ring 22 is interposed between the inner circumferential surfaces of.

A plunger 23 having a tapered upper part is slidably movable up and down inside the plunger case 21, and a plug 25 is fitted into the open upper end 24 of the plunger 23. A slipper member 27 is fitted into the recess 26 formed in the upper part of the plug 25 via an O-ring 29, and a slipper surface 28 is formed on the top surface of the slipper member 27. The lower end of an adjusting screw 30 that is adjustably screwed into the tip of the lever 9 is brought into contact.

The plunger 23 defines a high-pressure oil chamber 31 in the lower part of the plunger case 21, and a replenishment oil chamber 32 in the upper part thereof.

A valve port 33 is opened in the bottom wall 23d of the plunger 23, and the high pressure oil chamber 31 and the replenishment oil chamber 32 communicate with each other through the valve port 33. Inside the high pressure oil chamber 31, there is a check valve V for opening and closing the valve port 33, and a plunger 23.
A tension spring 34 that springs the valve upward is housed in the check valve (2). It is composed of a valve spring 37 that urges the valve body 35 in the valve closing direction.

Below the O-ring 22, a side wall 21s of the plunger case 21 and a side wall 23 of the plunger 23.
S includes a refueling hole 38 that constantly communicates with each other, and a cuff 3.
The oil supply hole 38 is communicated with an oil supply passage 40 bored in the adjuster case 17, and the oil hole 39 is communicated with the oil supply chamber 32.

The oil supply passage 40 communicates with a discharge port 41 of the hydraulic pump P. Therefore, when the hydraulic pump p connected to the crankshaft 1 is driven as the engine is operating, pressurized oil from the pump always passes through the discharge port 41, the oil supply passage 40, the oil supply hole 38, and the oil hole 39. The refueling oil chamber 32 is forcibly refueled.

As clearly shown in FIG. 6, the oil supply passage 40 consists of a downstream passage 40d on the side of the oil supply chamber 32 and an upstream passage 40u on the side of the hydraulic pump P, and the open end of the downstream passage 40d is a plug. It is closed by a body 42. Downstream oil supply path 40d
A pressure regulating regulator R is built inside. The regulator R includes a piston 46 that is slidably fitted into the lower ilt side passage 40d to open and close the oil reservoir communication hole 44, and a spring 47 that biases the piston 46 toward the closing side. When the oil pressure inside rises above a predetermined value, the piston 46 is slid in the opening direction against the elastic force of the spring 47, and the oil sump communication hole 44 is communicated with the oil supply passage 40 to open the oil supply passage 4.
The pressurized oil in the engine body E is returned to the oil reservoir 48 at the bottom of the engine body E.

The outer periphery of the tapered upper part of the plunger 23 and the plunger 23
- An annular leak passage 51 is formed between the
This leak passage 51 is connected to the open upper end 24 of the plunger 23.
The plug 25 is communicated with the replenishment oil chamber 32 via a passage 56 formed between the fitting surfaces of the plug 25 and the plug 25 . Also, the O-ring 2
2 and the oil supply hole 38, an oil drain hole 49 is formed in the side wall 21s of the plunger case 21 and opens into the recess passage 51. It communicates with an oil reservoir 48 in the engine body E via an oil drain passage 50.

The oil in the supply oil chamber 32 flows into the passage 56 together with the trapped air.
The oil flows through the leak passage 51, and is further returned from the passage 5J to the oil sump 48 in the engine body E through the oil drain hole 49 and the oil drain passage 50.

Furthermore, as shown in FIG. This is for removing air sealed in the oil chamber 57 when the plunger case 21 is assembled into the oil chamber 57.

A tightening ring 5 is attached to the lower end of a boot 53 formed of rubber, synthetic resin, etc. on the outer peripheral surface of the upper end of the plunger case 21.
4, and the upper end of the boot 53 is inverted and tightened.
It is oil-tightly wrapped around the outer circumference of 5. The boot 53 expands and contracts to follow the elevation and descent of the plunger 23, thereby sealing the space between the plunger case 21 and the plug 25 in an oil-tight manner.

Next, the operation of the embodiment of the present invention will be explained.

When the engine is operated, the rotation of the crankshaft 1 is transmitted to a pair of valve drive camshafts 2 via a timed winding transmission T consisting of a drive pulley 3, a transmission belt 5, and a driven pulley 4.

Loose side of the transmission belt 55. Tension pulley 8 disposed at 5. It automatically operates in response to tension fluctuations in the transmission heald 5 to apply a constant tension to the transmission heald 5.

Next, the function of the auto-adjuster A will be explained in more detail.

The same oil as the lubricating oil of the engine is injected into the high-pressure oil chamber 31 and the supply oil chamber 32 in the plunger case 21 in advance.

In addition, a part of the pressurized oil from the hydraulic pump P for lubricating the engine connected to the crankshaft l is constantly forced into the replenishment oil chamber 32 through the discharge port 41, the oil supply passage 40, the oil supply hole 38, and the oil hole 39. The replenishment oil chamber 32 is filled with oil. Further, the oil in the replenishment oil chamber 32 passes through the passage 56 together with the trapped air sealed in the chamber 32, and passes through the leak passage 5.
1, and from there, it passes through an oil drain hole 49 and an oil drain passage 50, and is returned to the oil sump 48 at the bottom of the engine body E. In this case, the air trapped in the oil in the supply passage 32 is removed from the upper passage 5.
6 and is easily discharged from the leak passage 51 to the oil drain hole 49. The oil flowing between the hydraulic pump P, the auto adjuster A, and the oil reservoir 48 does not leak outside the engine body E.

When the oil pressure in the oil supply passage 40 exceeds a predetermined value, the piston 46 of the regulator R retreats against the elastic force of the spring 47, and the oil sump communication hole 44 communicates with the oil supply passage 40 to open the passage. The pressurized oil in 40 is returned to oil sump 48.

In the auto adjuster A, the tension spring 34 in the high pressure oil chamber 31 pushes up the plunger 23 with its elastic force, and moves the swing lever 9 via the slipper member 27 and the adjustment screw 30 as shown in FIG. Swings counterclockwise. Thereby, the tension pulley 8 presses the loose side 51 of the transmission belt 5 inward, and applies a constant tension to the transmission belt 5.

The elastic force of the tension spring 14 also urges the swinging lever 9 to swing counterclockwise in FIG. 1, thereby assisting in applying tension to the transmission belt 5.

When the plunger 23 rises following the elongation of the transmission belt 5, the pressure in the high-pressure oil chamber 31 is reduced, and the spherical valve body 35 of the check valve 2
3 is opened, and the oil in the replenishment oil chamber 32 is supplied to the high pressure oil chamber 31 through the valve port 33.

During operation of the timing winding transmission T, the slack side 5 of the transmission belt 5 is caused by torque fluctuations acting on the crankshaft 1, valve drive camshaft 2, etc. When a tensile force is applied to , this tensile force acts to push back the tension pulley 8 and further acts to push down the plunger 23 via the swing lever 9 . As a result, the oil pressure in the high-pressure oil chamber 31 increases and the spherical valve body 35 of the check valve V closes the valve port 33, thereby preventing oil from flowing back into the replenishment oil chamber 32, and eventually inside the high-pressure oil chamber 31. The hydraulic pressure of 5. on the loose side of the transmission belt 5. By resisting the tensile force of the tension pulley 8, the tension pulley 8 is prevented from retreating.

When the tensile force is released from the loose side 51 of the transmission belt 5,
The plunger 23 rises again due to the elastic force of the tension spring 34, and the tension pulley 8 is moved to the slack side 5. of the transmission belt 5 via the swing lever 9. is pressed to apply a constant tension to the transmission belt 5 again, and if there is any elongation in the transmission belt 5, this can be compensated for. The high-pressure oil chamber 31, which is depressurized by the rise of the plunger 23, is replenished with the oil in the replenishment oil chamber 32 as described above.

During the above operation, pressurized oil from the hydraulic pump P is constantly supplied into the replenishment oil chamber 32 as described above, so even if there is some leakage of oil in the replenishment oil chamber 32, this can be compensated for immediately. In addition, by constantly replenishing oil into the replenishment oil chamber 32, it becomes easier to discharge trapped air into the chamber 32, and as a whole, the automatic adjustment of the tension of the transmission belt becomes more accurate. It will be held on.

In the above embodiment, the tension boob IJ8 constitutes a tensioner according to the present invention.A second embodiment of the present invention is shown in Fig. 7.8.

In this second embodiment, a pump case 16 and an adjuster case 17 are formed separately, and the adjuster case 17 is directly fixed to the outer end surface of the pump case 16 with a plurality of bolts 60.

Therefore, in this second embodiment, the maintenance of the auto adjuster A is easy, and the auto adjuster A is easy to maintain.
The degree of freedom in attaching the pump to the pump case 16 increases, and the layout becomes easier.

The other structures are the same as those of the first embodiment.

For example, the sealed replenishment oil chamber inside the plunger case communicates its oil supply hole with the hydraulic pump and its oil drain hole with the oil reservoir of the engine body, and also communicates between the plunger that is slid into the plunger case and the plunger case. form a leak passage,
Since the replenishment oil chamber is communicated with the oil drain hole through the leak passage, pressurized oil is continuously supplied to the sealed replenishment oil chamber in the plunger case, making it difficult for air to be trapped in the pond inside the chamber. In addition, the air trapped in the replenishment oil chamber can be quickly discharged outside the replenishment oil chamber through the leak passage, and as a result, the air bubbles in the hydraulic oil in the auto adjuster can be reported in the report. In addition, the transmission efficiency of the wrapped transmission device is greatly increased by eliminating the possibility of oil adhering to the wrapped transmission device. I can do it.

[Brief explanation of the drawing]

Figures 1 to 6 show an embodiment of the device of the present invention.
The figure is a front view of a timing winding transmission device for an internal combustion engine equipped with the device of the present invention, FIG. 2 is a side view taken along the line ■ in FIG. 1, and FIG. The enlarged sectional view, Figure 4, is
Figure 2: Back view of the pump case along line IV-IV, No. 5
The figure is an enlarged sectional view taken along the line V-V in FIG. 2, FIG. 6 is a sectional view of the adjuster case taken along the line Vl-VT in FIG. 7 is a front view of a part of the pump, and FIG. 8 is a cross-sectional view taken along the line ■--■ in FIG. 7. E... Engine body, ■... Check valve, P... Hydraulic pump 3... Driving pulley, 4... Driven pulley, 5... Transmission -, Rut, 51... Loose side, 8... Tension pulley, 17... Adjuster case, 21... Plunger case, 23... Plunger, 31... High pressure oil chamber, 32... Supply oil chamber, 33... Valve port, 34...
Tension spring, 38... Oil supply hole, 4th... Oil sump, 49.
・・Drain hole, 51・-Lee passage Patent Applicant: Honda Motor Co., Ltd. Tanaka Machine Co., Ltd. Figure 3, Figure 4

Claims (1)

[Claims] In an internal combustion engine, an endless transmission belt is suspended between a driving pulley and a driven pulley supported by an engine body, and a tensioner is pressed against the loose side of the transmission belt to apply a predetermined tension to the transmission belt. In a tensioner device for a wrap-around transmission, a plunger case is provided in the engine body, and a plunger connected to the tensioner is slid onto the plunger case to provide a high-pressure oil chamber in the lower part of the plunger case and a sealed upper part thereof. The high-pressure oil chamber and the replenishment oil chamber are communicated through a valve port formed in the plunger, and the high-pressure oil chamber has a valve port that is closed when the pressure in the chamber is increased. , and a check valve that opens the valve port when the pressure is reduced; and a tension spring that biases the plunger in the extension direction and applies a predetermined tension to the slack side via the tensioner; The oil supply hole is connected to the hydraulic pump, and the oil drain hole is connected to the oil reservoir of the engine body, and a leak passage is formed between the plunger and the plunger case, and the oil supply chamber is connected to the drain through the leak passage. A tensioner device for a wrap transmission in an internal combustion engine, characterized in that the tensioner device communicates with an oil hole.