JPS5840241Y2 - Screwdriver device for engine valve timing adjustment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a screw driver device for adjusting the valve timing of an engine, and in particular, adjusts the screwing amount of an adjustment screw attached to a rocker arm of an engine valve system, and also controls the lock nut of the adjustment screw. This invention relates to a screwdriver device that can be tightened and loosened.

Conventionally, the valve tying of the intake and exhaust valves of overhead drive type engines and overhead cam type engines was
When one end of the bushing rod or rocker arm is in contact with the inner part of the base of the camshaft and the intake and exhaust valves are completely closed, the tip of the adjustment screw attached to the other end of the rocker arm and the bushing rod Insert a thickness gauge of a predetermined thickness between the top end of the adjustment screw attached to the rocker arm or between the tip of the adjustment screw attached to the rocker arm and the top end of the valve stem, and insert the adjustment screw into the rocker arm to the extent that it can be easily pulled out. By tightening the lock nut at the screwed-in position, the clearance between the adjustment screw and the bushing rod or valve stem can be adjusted, so-called tappet clearance adjustment.By performing this adjustment, the specified crank rotation angle can be achieved. Adjustments were made to ensure that a predetermined amount of doku-lubu lift was obtained.

However, such adjustments are not made by actually measuring when the intake and exhaust valves open, close, or open at a predetermined lift amount in relation to the crank rotation angle, but by calculating them from the cam blow file. Since it is estimated based on the above, it includes machining errors and assembly errors of valve train elements, especially cams, resulting in variations in valve timing from engine to engine.

In view of the above-mentioned circumstances, the opening amount of the intake and exhaust valves is actually measured from the valve lift amount at a predetermined crank rotation angle, and the adjustment screw is screwed in or loosened so that the opening amount becomes the predetermined value. An adjustment method in which valve timing is adjusted by adjusting the opening amount of the exhaust valve has already been proposed in Japanese Patent Application No. 122139/1983, which was filed by the same applicant as the applicant of the present application. There is.

In order to implement such an adjustment method effectively and efficiently, a control device that compares a measurement signal from a detection device that measures the opening amount of the intake and exhaust valves with a target value signal and outputs a command signal in accordance with the comparison is required. The adjustment screw is automatically screwed in or loosened according to the output signal of the device, and the adjustment screw must be fastened to the rocker arm by a lock nut at a predetermined screwed-in position without any rotation. In particular, it is an object of the present invention to provide a screw driver device for effectively and efficiently carrying out the valve timing adjustment method as disclosed in the specification of Japanese Patent Application No. 51-122139 mentioned above.

This purpose, according to the present invention, includes a screw driver element that rotates an adjustment screw screwed onto a rocker arm of an engine valve system, and a screw driver element rotatably mounted on the outer periphery of the screw driver element and screwed onto the adjustment screw. A first rotational force transmission including a socket wrench element that rotates a lock nut, first and second rotary actuators that rotate in forward and reverse directions, and a worm gear that transmits the rotational force of the first rotary actuator to the screw driver element. a second rotational force transmitting device for transmitting the rotational force of the second rotary actuator to the socket wrench element; and a displacement amount for measuring the axial displacement amount of the valve, the second rotational force transmitting device having a contact element that comes into contact with the valve retainer. a detection device, a crank angle detection device that detects an arbitrary rotation angle of the engine crank, and actuation of the first rotary actuator in response to an output signal of the displacement amount detection device and an output signal of the crank rotation angle detection device. This is achieved by a screw driver device for adjusting valve timing, characterized in that it includes a control device for controlling the valve timing.

A lock nut of an adjustment screw in an engine valve train is generally tightened with a large tightening torque on the order of several hundred kg-cm.

Therefore, when tightening the lock nut, in order to prevent the adjustment screw from turning, it is necessary to clamp the lock nut with a torque value on the same order of magnitude as the tightening torque of the lock nut.

In the case of the present invention, since the rotational force transmission device that transmits the rotational force of the rotary actuator to the screwdriver includes a worm gear, the screwdriver element rotates at a desired large order torque value due to its self-locking action. This means that there is no risk of the adjustment screw being screwed in incorrectly when tightening the lock nut.

In this case, butt crush in gear drive systems such as worm gears becomes a problem, but this is caused by screwing in the adjustment screw a little more than the set screw-in amount, then rotating it counterclockwise (clockwise) to position it at the set screw-in position. This can be resolved by rotating and tightening, and the adjustment screw will not rotate when the lock nut is fastened due to backlash present in the drive system of the screwdriver, and will be reliably locked at the correctly set position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an embodiment of the valve timing adjustment of an engine using a screw driver device according to the present invention.

In FIG. 1, 1 is an engine, 2 is a clamping device for clamping the flywheel 3 of the engine 1 and fixing the crankshaft at an arbitrary crank rotation angle, and 4 is a crank rotation angle from the flywheel 3 to the crankshaft. 5 is a valve opening amount detection device that detects the opening amount of the intake and exhaust valves; 6 is a screw driver device according to the present invention; 7 is the crank rotation angle peak m* 4 and the valve opening amount detection device 5, and outputs a sequence control signal to the screw driver device 6 in accordance with the input detection signals.

The crank rotation angle detection device 4 may be arranged on the front side of the engine so as to index and detect the crank rotation angle from the rotation angle of the crank pulley.

FIG. 2 is a longitudinal cross-sectional view showing in detail the valve train of the engine, the valve opening amount detection device, and the screw driver device according to the present invention.

The engine 1 includes an intake valve 8 and an exhaust valve 9. The intake valve 8 and the exhaust valve 9 open and close an intake port 11 and an exhaust port 12 formed in a cylinder head 10, respectively, and a valve stem 13, The valve springs 17 and 18 installed between the retainers 15 and 16 installed at the tips of each of the valves 14 and the cylinder head 10 move upward in the figure in the direction of closing the valve with a predetermined spring installation load. energized.

The cylinder head 10 rotatably supports a camshaft 20 equipped with cams 19 corresponding to each of the intake and exhaust valves at the center of its upper part, and also rotatably supports rocker arms 21 and 22 on both sides of the camshaft 20. A rocker shaft 23 for the intake valve and a rocker shaft 24 for the exhaust valve are integrally supported.

Each rocker arm 2L22 has a butt surface 25.2 at one end.
Adjustment screws 27, 2 which are in sliding contact with the land surface of the cam 190 at 6 and have a locking nut (29.30) at the other end.
8 is screwed on, and the intake and exhaust valves 8,
The valve stems 9 are brought into contact with the upper end surfaces of the valve stems 13 and 14 of each of the valve stems 9 .

The structure described above is a general structure of an overhead cam type engine.

The valve opening amount detection device 5 includes a displacement meter 31 such as a differential transformer to detect the opening amount of the intake and exhaust valves as a valve lift amount.

The displacement gauge 31 is supported by a movable support device 32 so that it can approach and move away from the intake and exhaust valve portions of the engine 1.

The displacement meter 31 has a detection arm 3 equipped with a contact 33 at the tip.
4, and during measurement, the contactor 33 as shown in the figure.
is positioned in contact with the upper surface of the retainer 15 (or 16), and detects the movement of the retainer in the valve axis direction to detect the valve lift amount.

The valve lift amount signal output from the displacement meter 31 is sequentially input to the logic control device 7 shown in FIG.

In addition to detecting the valve lift amount as described above, the valve opening amount detection device 5 may also be used, for example, by supplying appropriate compressed air to the intake/exhaust port of the valve to be adjusted, and detecting air pressure or air as the valve opening amount changes. The valve opening amount may be detected by measuring a change in the amount.

The screwdriver device 6 according to the present invention has a fixed base 50
The unit housing 51 is supported substantially vertically movably and is accessible from above the adjusting screw and lock nut.

The unit housing 51 has a round rod-shaped screw driver element 53 including a flat tip 52 that can be engaged with the slot of the adjustment screw, and two upper and lower sleeves 54.5.
5 and ball bearings 56, 57, and 5B, it is supported rotatably and movably in its axial direction.

The screwdriver element 53 is attached to the unit housing 5
The air cylinder device 60 is connected via a ball 62 to a piston rod 61 of an air cylinder device 60 that is attached to the air cylinder device 60 via a fitting 59 to the air cylinder device 60, and is pushed with a predetermined load by the air cylinder device 60 in the direction of engaging with the slot of the adjustment screw. It has become so.

The screwdriver element 53 is mutually rotatable with respect to the lower sleeve 55, but is connected to the upper sleeve 54 by a key 63 and is connected to a first rotary actuator for driving the screwdriver, in this embodiment. In the case of , an electric motor 6 with an electromagnetic clutch brake capable of forward and reverse rotation
4 is transmitted to the sleeve 54 via the power transmission system, so that the sleeve 54 rotates in the forward and reverse directions.

The electric motor 64 is fixed to the unit housing 51, and its motor shaft 65 is connected to a worm shaft 66 via a joint element 76.

The worm shaft 66 is rotatably supported by the unit housing 51 via ball bearings 67 and 68.
It is equipped with a worm 69.

The worm 69 is connected to a worm wheel 73 that is integrally supported by an intermediate shaft 72 that is rotatably supported by the unit housing 51 via ball bearings 70 and 71.
650 rotations of the motor shaft are transmitted to the intermediate shaft 72 at a reduced speed.

The intermediate shaft 72 integrally carries a bevel gear 74 at one end thereof, which bevel gear 74 is connected to the sleeve 54.
The rotation of the intermediate shaft 720 is transmitted to the sleeve 54 by meshing with a bevel gear 75 integrally attached to the outer periphery of the intermediate shaft 720.

The sleeve 55 extends close to the flat tip 52 of the screwdriver element 53 and has a square cross section, and carries a socket wrench element 77 in its extension.

Socket wrench element 77 is connected to sleeve 55 by pin 78.
It is connected to be movable only in the axial direction thereof, and is biased downward in the figure by a compression coil spring 79 installed between it and the unit housing 51, that is, in the direction of engagement with the lock nut 29. ing.

The socket wrench element 77 rotates integrally with the sleeve 55 by being rotated forward and backward by the second rotary actuator for driving the socket wrench, in this embodiment, the air nut liner 80. There is.

A motor shaft 81 of the air nut liner 80 is connected to a gear shaft 83 via a joint element 82.

The gear shaft 83 is rotatably supported by the unit housing 51 by ball bearings 84 and 85,
A spur gear 86 is provided at one end.

The spur gear 86 is an idle gear 8 rotatably supported by the unit housing 51 via an intermediate gear shaft 87.
8, this idle gear 88 meshes with the sleeve 55.
It meshes with a spur gear 89 formed on a part of the outer peripheral surface of.

Therefore, the rotational force of the air nut liner 800 is the same as that of the motor shaft 81. joint element 82, gear shaft 83, spur gear 86,
It is transmitted to the socket wrench element 77 via the idle gear 88, the spur gear 89, and the sleeve 55.

In the illustrated embodiment, a pressing lever element 90 is also provided which presses the rocker arm of the engine against the land surface of the cam.

This pressing lever element 90 is connected to the unit housing 51.
It is rotatable about a pivot shaft 91 supported by the air micro cylinder device 92, and is connected at one end to a piston rod 93 of the air micro cylinder device 92.
Due to the operation of the rocker arms 21, 220, the pad surface 2
5.26 selectively presses against the land surface of the cam 19.

This pressing mechanism causes the pad surface of the rocker arm to cam due to the total load of the engagement load of the screw driver element 53 given by the air cylinder device 60 and the engagement load of the socket wrench element 77 given by the compression coil spring 79. This is to prevent the valve from floating above the land surface of the engine, and therefore, it is not necessarily necessary as long as the total load is smaller than the valve spring load of the engine.

In general engines, the valve spring load is sufficiently greater than the total load, so the above-mentioned pressing mechanism is not necessary.

Each of the above-mentioned air cylinder device 60, electric motor 64 with electromagnetic clutch brake, air nut liner 80 button, and air micro cylinder device 60, 92 is automatically operated in sequence based on the above-mentioned logic control device 70 command. This will become clear in the operation description below.

Next, a case will be described in which the valve adjustment of the intake valve 8 is performed using the screw driver device according to the present invention.

When the engine whose valve timing is to be adjusted is a four-cylinder engine, the engine is set to the valve timing adjustment work position with the pistons of the first and second cylinders at the top dead center position.

Once the engine set-up is complete, flywheel 3
The outer periphery of the crankshaft is clamped by the lamp device 2, and the crank rotation angle is determined using this position as the indexing origin.

For example, if you want to adjust the valve timing of the intake valve based on the valve lift amount Le at point E on the lift curve of the intake and exhaust valves shown in FIG. Rotate the crankshaft until angle θe is detected.

Figure 3 shows the valve lift amount on the vertical axis and the crank rotation angle on the horizontal axis, where 1 is the lift curve of the exhaust valve,
11 shows the lift curve of the intake pulp.

When adjusting the valve timing of an intake valve, in addition to the above-mentioned point E, points C, F, G, etc. can be used as adjustment standards, and in the case of exhaust valves, points A, B, C, etc.
Point, D point, etc. can be used as the adjustment reference.

In this case, since point C is the common point for the intake and exhaust valves (the point where the intake and exhaust valves both open and exhibit the same valve lift amount at the same crank rotation angle), the valve timing is adjusted using this point C as the adjustment reference. In this case, by rotating the crankshaft to a predetermined crank rotation angle prior to adjusting the valve timing of the intake and exhaust valves, the valve timing of the intake and exhaust valves can be adjusted without adjusting the crank rotation angle thereafter.

Once the crank rotation angle has been determined as described above,
The displacement gauge 31 of the valve opening detection device 5 is advanced to bring its contact 33 into contact with the upper surface of the retainer 15 of the intake valve 8 as shown, and the unit housing 51 is lowered to touch the flat tip of the screw driver element 53. portion 52 is engaged with the slot in the head of adjustment screw 270 and socket wrench element 77 is engaged with lock nut 29.

When the start switch is operated in this state, the air cylinder device 60 is actuated, thereby causing the screwdriver element 5
3 is pressed toward the adjusting screw 27 with a predetermined load, for example, about 2 kg, and at this time, the socket wrench element 77 is pressed against the lock nut 29 by the spring force of the compression coil spring 79.

If it has a pressing mechanism, the air cylinder device 6
0 is activated, the air micro cylinder device 92 of the pressing mechanism is activated, and the pressing lever 90 is moved to the rocker arm 21.
The butt surface 25 of the cam 190 is pressed against the land surface of the cam 190.

When all of the above-mentioned settings are completed, the air nut liner 80 is driven in reverse rotation to rotate the socket wrench element 77 to the left and loosen the lock nut 29 from the adjustment screw 27.

When the lock nut 29 is loosened by a predetermined amount, the reverse rotation of the air nut liner 80 is stopped, and then the electric motor 64 is driven to rotate in the reverse direction.

Then, the rotational force is applied to the motor shaft 65 and the joint element 7.
6, worm shaft 66, worm 69, worm wheel 73, intermediate word 72, bevel gear 74.75. The signal is transmitted to the screwdriver element 53 via the sleeve 54 and the key 63, and the screwdriver element 53 rotates to the left.

By turning the screw driver element 53 to the left, the adjustment screw 27 is screwed upward in the figure.

When the tip of the adjustment screw 27 is screwed up to the extent that it separates from the upper end surface of the valve stem 13, the reverse rotation of the electric motor 64 is stopped.

At this time, the intake valve 8 is in a completely closed state, and the height of the upper surface of the retainer 15 at this time is measured with the displacement meter 31.
Set this point to auto zero so that it becomes the point of heavy snowfall on the valve lift.

After this, the electric motor 64 is driven to the forward rotation point.

Then, the screw driver element 53 is rotated to the right, so that the adjustment screw 27 is screwed downward as shown in the figure and hits the upper end surface of the valve stem 13, further pushing the intake valve 8 against the spring force of the valve spring 17 as shown in the figure. This will cause the valve to drop downward and open the valve.

At this time, for example, if point E in FIG. When a predetermined amount of large lift is detected,
The forward rotation of the electric motor 64 is stopped.

Thereafter, the electric motor 64 is rotated in the opposite direction, causing the screw driver element 53 to rotate to the left and screw the adjustment screw 27 upward again.

As a result, when the displacement shape 31 detects the set value Le,
Reverse rotation of the electric motor 64 is stopped.

That is, the adjustment screw 27 has been screwed into the predetermined screwing position.

Then, the air nut liner 80 is driven to rotate in the forward direction.
As a result, the socket wrench element 77 is rotated clockwise, thereby tightening the lock nut 29 and locking the adjustment screw 27 in a predetermined screwed-in position.

Thereafter, the height of the retainer 15 is measured by the displacement meter 31, it is checked whether it is at a predetermined setting position, and a determination signal is output.

Furthermore, when the lock nut 29 is fastened, the adjustment screw 27 engages with the screw driver element 53, and the screw driver element 53 is operatively connected to the electric motor 64 via a worm gear consisting of a worm 69 and a worm wheel 73. Therefore, the adjustment screw 27 is firmly locked in its screwed-in position by the self-locking action of the worm gear, and will not rotate with the locking wheel's 1290 rotations, thereby preventing the screw-in amount from becoming incorrect.

Further, the adjustment screw 27 is placed in the correct screwed-in position by turning it to the left, and is fastened to that screwed-in position by tightening the lock nut by turning it to the right.
The adjustment screw 27 will not rotate due to the adjustment in step 5 and will be locked at the correct position.

Although the present invention has been described in detail with respect to specific embodiments above, it will be appreciated by those skilled in the art that the present invention is not limited thereto, and that various embodiments are possible within the scope of the present invention. It should be obvious.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an example of adjusting the valve timing of an engine using the screw driver device according to the present invention, and Fig. 2 shows the valve timing adjustment using the screw driver device according to the present invention. FIG. 3 is a vertical cross-sectional view showing the main parts of the case, and FIG. 3 is a graph showing the lift curve of the intake and exhaust valves of the engine. DESCRIPTION OF SYMBOLS 1... Engine, 2... Clamp device, 3... Flywheel, 5... Valve opening amount detection device, 6... Screw driver device, 7... Logic control device, 8...
・Intake valve, 9... Exhaust valve, 10... Cylinder head, 11... Intake port, 12... Exhaust port, 13° 14... Valve stem, 15.16...
Retainer, 17.18... Valve spring, 19.
...Cam, 20...Cam shaft, 21.22-...Rocker arm, 23゜24...Rocker shaft, 25, 26-...
Butt surface, 27° 28... Adjustment screw, 29
, 30... Lock nut, 31... Displacement meter, 32...
...Movable support device, 33--Contactor, 34--Detection arm, 50--Fixed base, 51--Unit housing, 52--Flat tip, 53--Screw driver element, 54, 55...Three 7, 56, 57
, 58... Ball bearing, 59... Mounting tool, 6
0... Air cylinder device, 61... Piston rod, 62-... Ball, 63... Key, 64... Electric motor with electromagnetic clutch brake, 65... Motor shaft, 66
...Worm shaft, 67.68...Ball bearing, 69...Worm, 70,71...Ball bearing, 72...Intermediate shaft, 73-...Worm wheel, 74,75... Bevel tooth L76...joint element, 77...socket wrench element, 78--pin,
79...Compression coil spring, 80...Air nut liner, 81...Motor shaft, 82...Joint element, 83...Gear shaft, 84.85...Ball bearing, 86...・Spur gear, 87...Intermediate gear shaft, 8
8...Idle gear, 89...Spur gear, 90...
Pressing lever element, 91... Pivot, 92... Air micro cylinder device, 93... Piston rond.

Claims (1)

[Scope of utility model registration request] a screw driver element for rotating an adjustment screw screwed onto a rocker arm of an engine valve system; a socket wrench element for rotating a lock nut rotatably attached to the outer periphery of the screw driver element and screwed onto the adjustment screw; a first rotational force transmission device including second and second rotary actuators that rotate in opposite directions; a worm gear that transmits the rotational force of the first rotary actuator to the screw driver element; a second rotational force transmission device that transmits rotational force to the socket wrench element; a displacement detection device that has a contact that contacts the valve retainer and measures the amount of axial displacement of the valve; The crank angle detection device includes a crank angle detection device that detects an angle, and a control device that controls the operation of the first rotary actuator in response to an output signal of the displacement amount detection device and an output signal of the crank rotation angle detection device. A screwdriver device for adjusting valve timing, characterized by: