JPS61215846A - Tensioner apparatus in laying transmission apparatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To apply an autoadjustor onto the tensioner of a belt type laying transmission apparatus by preventing oil from leaking from the autoadjustor to the outside. CONSTITUTION:An oil feeding port 26 for the communication of a supplied-oil chamber 32 to the outside is opened at the upper edge of a plunger 23. A cap 27 connecting to a tensioner 8 is installed oiltightly at the oil feeding port 26. A high-pressure oil chamber 31 and the supplied-oil chamber 32 are allowed to communicate through a valve port 33 formed onto the bottom wall of the plunger 23. Further, a check valve V and a tension spring 34 are accommodated into the high-pressure oil chamber 31. Further, the supplied-oil chamber allows an oil feeding hole to communicate to an oil feeding source.

Description

Detailed Description of the Invention A6 Object of the Invention (11 Industrial Application Fields) The present invention is directed to an internal combustion engine in which an endless power transmission band suspended between a driving wheel and a driven wheel supported by an engine body automatically This invention relates to a tensioner device for a wrap-around transmission that applies a constant tension to the belt.

(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 Incidentally, in the auto adjuster of the conventional tensioner device, the oil supply chamber is open to the outside, and when the oil supply chamber is operated, a part of the oil leaks to the outside. If applied to a tensioner device of a two-wrap belt transmission, there is a risk that leaked oil may adhere to the two-wrap belt transmission, making it difficult to apply to such a device.

Therefore, the present invention prevents oil from leaking to the outside from an oil-filled auto-adjuster, making it possible to apply it to a tensioner device of a two-belt transmission device, and making it easy to fill the high-pressure oil chamber of the auto-adjuster with oil. Furthermore, the manufacturing cost of the plunger itself can be reduced.
It is an object of the present invention to provide a tensioner device for a wrap transmission in an internal combustion engine.

B0 Configuration of the Invention +11 Means for Solving Problems To achieve the above object, according to the present invention, an endless transmission belt is suspended between a driving pulley and a driven pulley supported by an 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 transmission belt, a plunger case is provided in the engine body, and a plunger case is provided with a plunger during the plunge. The plunger is slid together to form a high-pressure oil chamber below the plunger and a replenishment oil chamber therein, and an oil fill hole is opened at the upper end of the plunger to communicate the replenishment oil chamber to the outside. , a cap connected to the tensioner is provided in an oil-tight manner, and the high pressure chamber and the replenishment oil chamber are communicated via a valve hole bored in the bottom wall of the plunger, and the high pressure oil chamber is provided with a supply oil chamber. a check valve that closes the valve port when the pressure 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, Further, the replenishment oil chamber communicates its oil supply hole with an oil supply source.

(2) Function The oil circulating between the hydraulic pump, the auto adjuster, and the oil reservoir in the engine body does not leak out of the engine body, and the plunger can be easily left installed during assembly and maintenance of the auto adjuster. High-pressure oil can be filled with oil, and the plunger does not have a connecting part to the tensioner that requires hardness, so it can be manufactured at low cost.

(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 T has a conventionally known structure, and has an endless shape between a driving pulley 3 fixed to a crankshaft 1 and driven pulleys 4 fixed to a pair of valve drive camshafts 2, respectively. It is constructed by suspending a transmission belt 5. 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, a tension pulley 8 is provided on the outside of the loose side 51 of the transmission belt 5 between the drive boob IJ 3 and the other driven pulley 6, and this tension pulley 8 is connected to the swing lever 9. Pulley shaft 1 protruding from the middle part of
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 moved to the slack side 5. of the transmission belt 5. It is biased so that it comes into pressure contact with the outer surface.

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 l. 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 I7 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.

Inside the plunger case 21, a plunger 23 is slidably movable up and down. Below the plunger 23,
The bottom wall 23d of this plunger 23 and the plunger case 2
1 forms a high-pressure oil chamber 31, and a replenishment oil chamber 32 is formed within the plunger 23.

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 valve V for opening and closing the valve port 33, and a plunger 23.
The check valve V includes a spherical valve body 35 that is seated on the valve seat of the valve port 33, a pulp cage 36 that accommodates the valve body 35, and a pulp cage 36 that accommodates the valve body 35. It is composed of a valve spring 37 that urges the valve body 35 in the valve closing direction.

A plug 25 is fitted into the open upper end 24 of the plunger 23 . An oil filling hole 26 is bored in the center of the plug 25 to communicate the replenishing oil chamber 32 to the outside, and an O-ring 29 is connected to the upper end of the oil filling hole 26 to connect the cap 26 to the outside.
7 is fitted, and the top surface of the cap 27 is formed with a connecting surface 28 which has been subjected to a heat hardening treatment such as quenching, and this connecting surface is adjustably screwed onto the tip of the swing lever 9. The lower end of the adjustment screw 30 is connected.

Below the O-ring 22, the side wall 21S1 of the plunger case 21 and the 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 pop P. Therefore, when the hydraulic pump P connected to the crankshaft l 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 downstream 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 of the spring 47 increases to a predetermined value or more, the spring 47
The piston 46 is slid in the opening direction against the elastic force of the piston 46, the oil sump communication hole 44 is communicated with the oil supply passage 40, and the pressurized oil in the oil supply passage 40 is returned to the oil sump 48 at the bottom of the engine body E. It looks like this.

Between the O-ring 22 and the oil supply hole 38, an oil drain hole 49 is bored in the side wall 21g on the plunger case 21 side. The oil drain hole 49 opens into an annular chamber 51 formed between the plunger case 21 and the plunger 23, and communicates with an oil reservoir 48 in the engine body E through an oil drain passage 50 formed in the housing 19.

The replenishment oil chamber 32 in the plunger 23 is communicated with the annular chamber 51 through a leak passage 56 formed between the open upper end 24 of the plunger 23 and the fitting surface of the plug 25, and the oil in the replenishment oil chamber 32 is It flows along with the trapped air into the annular chamber 51 through the leak passage 56, and is further returned from the annular chamber 51 through the oil drain hole 49 and the oil drain passage 50 into the oil reservoir 48 in the engine body E. .

Furthermore, as shown in FIG. 5, an air vent passage 52 is provided at the bottom of the housing 19 to communicate the lower part of the high pressure oil chamber 31 with the discharge port 41 of the oil pump P. This is for removing air sealed in the oil chamber 31 when the plunger case 21 is assembled therein.

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 attached to the plug 25 by a tightening ring 55.
It is oil-tightly wrapped around the outer periphery of the 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 the 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.

The tensile lamp pulley 8 disposed on the slack side 51 of the transmission belt 5 is pressed against the transmission belt 5 by an auto adjuster A, and the tensioner pulley 8 is placed in pressure contact with the transmission belt 5 on the slack side 51 of the transmission belt 5. It automatically operates in response to tension fluctuations in the transmission belt 5 to apply a constant tension to the transmission belt 5.

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

The same oil as the engine's lubricating oil is injected into the high-pressure oil chamber 31 in the plunger case 21 in advance. In this case, if the cap 27 is removed from the plug 25 as shown in FIG.
is opened to the outside, so if the push rod B is inserted into the replenishment oil chamber 32 inside the plunger 23 through the oil filling hole 26 and the spherical valve body 35 is pushed down, the valve port 33 opens and the plunger 23 is assembled. Oil can be injected and filled into the high pressure oil chamber 31 as it is.

When the lubrication hydraulic pump P is driven by the operation of the engine,
A part of the pressurized oil from there is delivered to the discharge port 41, the oil supply passage 40,
The replenishing oil chamber 32 is always forcibly supplied with oil through the oil supply hole 38 and the oil hole 39, and the replenishing oil chamber 32 is filled with oil. Further, the oil in the replenishment oil chamber 32 passes through the leak passage 56 together with the trapped air sealed in the chamber 32 to reach the annular chamber 51, and from there passes through the oil drain hole 49 and the oil drain passage 5o to the engine body. It is refluxed into the oil sump 48 at the bottom of E.
'Therefore, the oil circulating between the hydraulic pump P1 auto-adjuster A and the oil reservoir 48 of the engine E does not leak outside the engine body E, and lubricating oil is constantly supplied to the replenishing oil chamber 32 of the adjuster A during engine operation. be done.

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, causing the passage 4o The pressurized oil inside is returned to the oil reservoir 48.

In the auto adjuster A, the tension spring 34 in the high pressure oil chamber 31 pushes the plunger 23 upward with its elastic force, and moves the swing lever 9 through the connecting surface 28 made of the hardened layer and the adjustment screw 3o. In FIG. 1, it swings counterclockwise. As a result, the tension pulley 8 is connected to the transmission heald 5.
5 degrees of the loose side of the transmission belt 5 is pressed inward to apply 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 suppresses the retreat of the tension pulley 8 by opposing the tensile force on the loose side 5I of the transmission belt 5.

In this case, the pressure oil in the high pressure oil chamber 31 is absorbed by the sliding gap between the plunger case 21 and the plunger 23 and the high pressure oil chamber 31.
This is due to the fact that the oil contains some air bubbles inside.
In reality, the plunger 23 sinks slightly, thereby making it possible to alleviate the tensile impact acting on the loose side 51 of the transmission belt 5.

Loose side of transmission belt 55. When the tensile force is released from
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 in

In the above embodiment, the tension pulley 8 constitutes the tensioner in the present invention.As is clear from the above embodiments, according to the present invention, a plunger case is provided in the engine body, and the plunger is installed in the plunger case. are slid together to form a high-pressure oil chamber below the plunger and a replenishment oil chamber within the plunger, and an oil supply hole is opened at the upper end of the plunger to communicate the replenishment oil chamber to the outside, and the oil supply hole A cap connected to the tensioner is provided in an oil-tight manner, and the high pressure chamber and the replenishment oil chamber are communicated through a valve port bored in the bottom wall of the plunger, and the high pressure oil chamber includes: a check valve that closes the valve port when the pressure 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 of the transmission belt via the tensioner. Moreover, since the replenishing oil chamber communicates its oil supply hole with the oil supply source, when filling the high pressure oil chamber of the auto adjuster with oil, the plunger is installed in the plunger case and the oil supply hole is communicated with the oil supply source. The plunger can be easily filled with oil, making assembly, maintenance, etc. of the plunger easier.

Further, the plunger does not need to form a connecting surface to the tensioner that requires hardening treatment, and the manufacturing cost can be reduced.

Further, the automatic adjuster does not have to worry about leaking oil to the outside during its operation, assembly, or maintenance, and the transmission efficiency of the belt two-wrap transmission device can be improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the device of the present invention, and FIG. 1 is a front view of a timing winding transmission device for an internal combustion engine equipped with the device of the present invention, and FIG. Side view, Figure 3 is the 1st
The enlarged sectional view taken along the line m-m in Figure 4 is the same as that in Figure 2 IV-
A front view of the pump case taken along line IV, FIG. 5 is an enlarged sectional view taken along line V-V in FIG. 2, and FIG.
FIG. 7 is a cross-sectional view of the adjuster case taken along line I, and is a cross-sectional view showing the state when oil is injected into the high-pressure oil chamber. E... Engine body, ■... Check valve, P... Hydraulic pump as oil supply source 3... Drive pulley, 4... Driven pulley, 5... Transmission belt, 21... Plunge Middle case, 26...Oil filling hole, 27...Cap, 31...High pressure oil chamber, 32
...Replenishment oil chamber, 33...Valve port, 34...Tension spring patent applicant Honda Motor Co., Ltd. Tanaka Machine Co., Ltd. Figure 3 Figure 4 Isao Figure 2 Figure 5 @

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 transmission, a plunger case is provided in the engine body, a plunger is slid onto the plunger case to form a high-pressure oil chamber below the plunger, and a replenishment oil chamber inside the plunger. An oil filling hole is opened at the upper end to communicate the oil supply chamber to the outside, and a cap connected to the tensioner is provided in the oil hole in an oil-tight manner, and the high pressure chamber and the oil supply chamber are connected to the oil supply hole. The high-pressure oil chamber is connected to the high-pressure oil chamber through a valve port drilled in the bottom wall of the plunger, and includes a check valve that closes the valve port when the pressure in the chamber increases and opens the valve port when the pressure decreases, and the plunger moves in the extension direction. A tension spring biased to apply a predetermined tension to the slack side via the tensioner is housed, and the replenishment oil chamber has an oil supply hole communicating with an oil supply source. Tensioner device for hanging transmission.