JPS61215847A - Tensioner apparatus in laying transmission apparatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To effectively utilize all the stroke of an autoadjustor free from futility by connecting one edge of an adjusting screw screwed in adjustable ways onto a swing lever, onto the upper edge of a plunger. CONSTITUTION:A swing lever 9 is axially supported onto an engine body, and a tensioner 8 is supported onto the swing lever 9. A hydraulic type autoadjustor A is connected to the swing lever 9 through the tensioner 8. Said autoadjustor A is equipped with a high-pressure chamber 31 for suppressing the sinking of a plunger 23, check valve V and a supplied oil chamber 32. Further, an adjusting screw 30 screwed in adjustable ways onto the swing lever 9 is installed at the upper edge of the plunger 23. With such constitution, all the stroke of the autoadjustor can be utilized free from futility, and the dimension of the autoadjustor can be reduced.

Description

Detailed Description of the Invention A6 Object of the Invention (1) Industrial Field of Application The present invention provides an internal combustion engine in which automatic transmission is applied to an endless transmission band suspended between a driving wheel and a driven wheel supported by an engine body. The present invention relates to a tensioner device for a wrap-around transmission device that 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 By the way, the tensioner device is easy to assemble to the engine body, and adjusts the transmission band by effectively utilizing the entire stroke of the auto adjuster attached to the device. The auto adjuster can be made more compact, and if the auto adjuster is hydraulic, the unnecessary stroke can be eliminated. It is required that the oil hole formed in the internal relatively movable part be made as small as possible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tensioner device for a wrap transmission in an internal combustion engine that can satisfy such requirements.

B. Structure of the Invention (1) Means for Solving the Problems According to the present invention, in order to achieve the above object, an endless transmission band is suspended between a driving wheel and a driven wheel supported by an engine body, and the transmission band is suspended between a driving wheel and a driven wheel. In a tensioner device for a wrap transmission in an internal combustion engine, the tensioner device applies a predetermined tension to the transmission band by pressing a tensioner on the slack side of the transmission band, and the tensioner device includes a swing lever pivotally supported on the engine body. a tensioner supported by the swing lever; and a hydraulic auto-adjuster connected to the swing lever to apply a predetermined tension to the transmission band via the tensioner, the auto-adjuster comprising:
a plunger case provided in the engine body; a plunger slidably fitted into the case; a tension spring and spring biasing the plunger in a direction to project; a high pressure chamber and a check valve for preventing the plunger from sinking; It has a replenishment oil chamber for replenishing oil to the high pressure chamber, and one end of an adjustment screw adjustably screwed into the swing lever is connected to the upper end of the plunger.

(2) Effect According to the above configuration, the auto adjuster of the tensioner device can effectively utilize its entire stroke, and there is no waste in the stroke, and the oil circulation hole formed in the plunger case and plunger can be effectively used. It can be made smaller, and furthermore, it is easy to assemble the entire tensioner device and adjust the stroke.

(3) Embodiment A first embodiment in which the present invention is applied to a DOHC type 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 drive pulley 3 fixed to a crankshaft 1 and a driven boot +J4 fixed to a pair of valve drive camshafts 2, respectively. It consists of

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

Between the driving pulley 3 and the driven pulley for driving the water pump 7, a tension 7'-
A tension boolean IJ8 is provided, and this tension boob IJ8 is rotatably supported via a ball bearing 11 on a pulley shaft portion 91 protruding from an intermediate portion of the swing lever 9.

As clearly shown in FIG. 3, the swing lever 9 is pivotally supported at its base end 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. An arcuate hole 10 centered on the support shaft 12 is bored at the end of the pulley shaft portion 9I of the swing lever 9, and the arcuate hole 10 is connected to the guide shaft 15 fixed to the end wall 13 of the engine body E. The circular arc hole 10 and the guide shaft 1
5 engage with each other, and the swing angle of the swing lever 9 is regulated.

A hydraulic auto-adjuster A, which will be described in detail later, is connected to the free end of the swing lever 9, and the control force of this adjuster A is applied via the swing lever 9 to the tension pulley 8 on the loose side 51 of the transmission band 5. The swing lever 9 has a base end supported on the engine main body E at the intermediate portion thereof. The other end of an auxiliary spring 14 made of a tension spring is connected, and the elastic force of this auxiliary spring 14 biases the swinging lever 9 to swing counterclockwise around the support shaft 12, and the tension pulley 8 auxiliary to the loose side of the transmission belt 5. Press against the outside 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 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.

The adjuster case 17 of the hydraulic auto-adjuster λ is integrally cast on the outer surface of the pump case 16 of the hydraulic pump P.

Next, we will mainly explain the structure of this hydraulic 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 and housing of this plunger case 21.

An O-ring 22 is interposed between the inner peripheral surfaces of the ring 19.

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 spherical lower end 30 of the adjusting screw 30 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 there 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 path 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 It is closed by a stopper 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.

An annular air bleed road 51 is formed between the outer periphery of the tapered upper part of the plunger 23 and the plunger case 21, and this air bleed road 51 is formed between the fitting surface of the open upper end 24 of the plunger 23 and the plug 25. It communicates with the replenishment oil chamber 32 via a leak passage 56 formed therein. Further, between the O-ring 22 and the oil supply hole 38, the plunger case 21
An oil drain hole 49 that opens to the air bleed road 51 is formed in the side wall 21s of the engine, and this oil drain hole 49 drains oil in the engine body E through an oil drain passage 50 formed in the plunger case 17. It communicates with the reservoir 48.

The oil in the replenishment oil chamber 32 flows together with the trapped air through the leak passage 56 to the air vent road 51, and further flows through the passage 5.
1, the oil is returned to the oil reservoir 48 in the engine body E through the oil drain hole 49 and the oil drain passage 50.

Furthermore, as shown in FIG. 5, an air vent road 52 is bored in the bottom of the housing 19 to communicate the lower part of the oil chamber 31 and the discharge port 41 of the oil pump P. This is for removing air sealed in the oil chamber 57 when the plunger case 21 is assembled.

The lower end of a boot 53 made of rubber, synthetic resin, etc. is oil-tightly attached to the outer peripheral surface of the upper end of the plunger case 21 by a tightening ring 34, and the upper end of the boot 53 is inverted and tightened. The plug 2 is attached by a ring 55.
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 assembly procedure of the tensioner device will be explained. The swing lever 9, which is swingably supported on the engine body E by a support shaft 12, has an auxiliary spring 1 connected to the engine body E.
4 are connected to each other, and the swing lever 9 is held in a substantially use position together with the tension pulley 8. On the other hand, auto adjuster A
A tension spring 34 is built into the inner bottom of the adjuster case 21, and oil is injected into it. Next, insert the plunger 23 with the check valve ■ assembled into the lower end into the adjuster case 21.
Insert it inside from the top. Next, the spherical lower end 30 of the adjusting screw 30 screwed onto the tip of the swing lever 9 is brought into contact with the slipper member 28 at the upper end of the plunger 23, and the adjusting screw 30 is rotated in the tightening direction. The lower end of the plunger 23 is bottomed on the bottom surface of the plunger case 21 while compressing the tension spring 34. In this state, the tension pulley 8 is pressed against the loose side 5I of the transmission belt 5 to apply the desired tension to the belt 5, and the assembly of the tensioner device is completed.

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.

Loose side of the transmission belt 55. A tension pulley 8 disposed on the transmission belt 5 is pressed against the transmission belt 5 by an auto adjuster A, and automatically operates in response to tension fluctuations on the loose side 51 of the transmission belt 5, thereby maintaining a constant tension on the transmission belt 5. Grant. Further, the auxiliary spring 14 uses its elastic force to push the tension boob I78 toward the loose side 5 of the transmission band 5. auxiliary pressure contact.

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

A part of the pressurized oil from the hydraulic pump P for lubricating the engine connected to the crankshaft l is constantly forcedly supplied 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 supply oil chamber 32 is filled with oil. In addition, the oil in the replenishment oil chamber 32 passes through the leak passage 56 and the air bleed road 51 together with the trapped air sealed in the chamber 32, and then passes through the oil drain hole 49 and the oil drain passage 50 to the engine body. It is refluxed into the oil sump 48 at the bottom of E. In this case, the air trapped in the oil in the supply passage 32 passes through the leak hole 56 in the upper part and is easily discharged from the air vent road 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, the oil sump communication hole 44 communicates with the oil supply passage 40, and the passage 4
The pressurized oil in 0 is returned to the oil reservoir 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. As a result, the tension boob IJ 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 auxiliary 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 V is forced to close the valve port 3 due to the pressure difference with the replenishment oil chamber 32.
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, when a tensile force is applied to the loose side 51 of the transmission belt 5 due to torque fluctuations acting on the crankshaft 1, valve drive camshaft 2, etc., this tensile force pushes back the tension pulley 8. It also works 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 counteracting the tensile force 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 action of the tension spring 34, and the tension pulley 8 presses the loose side 51 of the transmission belt 5 via the swing lever 9, applying a constant tension to the transmission belt 5 again, and the transmission is stopped. If the belt 5 has elongation, 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.

A second embodiment of the invention is shown in Figure 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.

In addition, the auxiliary pulley 3 and the driven pulley 4 in the above embodiment
, the transmission belt 5, and the tension pulley 8 constitute a driving wheel, a driven wheel, a transmission band, and a tensioner in the present invention. Further, in the above embodiments, the present invention is applied to a two-belt transmission, but it can also be applied to a chain-type or other belt-wrapped transmission.

C0 Effects of the Invention As is clear from the above embodiments, according to the present invention, the tensioner device includes a swing lever pivotally supported on the engine body;
A tension supported by the swing lever, a tensioner, and a hydraulic auto-adjuster that is connected to the swing lever and applies a predetermined tension to the transmission band via the tensioner, and the auto-adjuster is connected to the engine body. a plunger case provided in the case, a plunger slidably fitted into the case, a tension spring biasing the plunger in the direction of protrusion, a high pressure chamber and a check valve for preventing the plunger from sinking, and a hydraulic chamber installed in the high pressure chamber. One end of the adjustment screw, which is adjustable and screwed onto the swing lever, is connected to the upper end of the plunger, so that the auto adjuster can be used only when the plunger is in its lowest position. This allows the entire stroke to be used effectively without waste, allowing for a large adjustment allowance for the transmission band, and also making it possible to make the auto adjuster itself more compact. In addition, the oil hole drilled between the plunger case and the plunger can be made as small as possible since there is no unnecessary stroke of the plunger as mentioned above, which facilitates machining and contributes to cost reduction. obtain.

In addition, a relatively strong tension spring can be easily compressed by rotating the adjustment screw, and the auto-adjuster can remain fixedly supported on the engine body, making it easier to assemble the entire tensioner device and adjust the stroke. can be significantly improved.

[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 from the line ■ in FIG. 1, and FIG. The enlarged sectional view, Figure 4, is the same as Figure 2 I.
5 is an enlarged sectional view taken along line V-V in FIG. 2, and FIG. 6 is a back view of the pump case taken along line V-IV.
7 and 8 are cross-sectional views of the adjuster case taken along the -Vl line, and show the second embodiment of the present invention. FIG. 7 is a front view of a part of the pump case, and FIG. −■Make a cross-sectional diagram of the cotton cross section. E... Engine body, A... Forced hydraulic auto adjuster 3... Drive wheel, 4... Driven wheel, 5... Transmission band, 5
1... Loose side, 8... Tension pulley, 9...
Swing lever patent applicant Honda Motor Co., Ltd. Tanaka Machine Industry Co., Ltd. Figure 2 μI Figure 3 Figure 4 Figure 7 Figure 8 Figure 5 (-)

Claims (1)

[Claims] In an internal combustion engine, an endless power transmission band is suspended between a driving wheel and a driven wheel supported by an engine body, and a tensioner is pressed against the loose side of the transmission band to apply a predetermined tension to the transmission band. In a tensioner device for a wrap-around transmission, the tensioner device includes a swing lever pivotally supported by the engine body, a tensioner supported by the swing lever, and a tensioner connected to the swing lever and connected through the tensioner. a hydraulic auto-adjuster that applies a predetermined tension to the transmission band; The device has a biasing tension spring, a high pressure chamber and check valve that prevents the plunger from sinking, and a replenishment oil chamber that replenishes oil to the high pressure chamber, and is provided at the upper end of the plunger and can be freely adjusted by the swing lever. 1. A tensioner device for a wrap transmission in an internal combustion engine, characterized in that one end of an adjusting screw screwed into the tensioner device is connected to the tensioner device.