JPH11153007A - Method for adjusting tappet clearance of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust easily and certainly the tappet clearance of a valve without a worker's high skill. SOLUTION: A clearance is formed between a valve 5 and a valve sheet 4 by sandwiching a thickness gage 11 between the valve 5 and an adjust screw 9, and high pressure air is supplied from an air source 21 to a combustion chamber 3. After a worker adjusts the screwing-in amount of the adjust screw 9 by a screwdriver 45, the worker temporarily fastens a lock nut 10 by a nut wrench 41 and further fastens the lock nut 10 by a torque wrench 48. When the tightening torque of the lock nut 10 reaches a predetermined value, a timing signal transmitted by an FM transmitter 30 is inputted to a judging device 29 through an FM receiver 31. The judging device 29 to which an AD conversion value of inner pressure of the combustion chamber 3 detected by a manometer 27 is inputted, judges the suitability of a tappet clearance by confirming whether or not the inner pressure of the combustion chamber 3 at the moment when the timing signal is outputted falls in the range of a set value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting tappet clearance of an intake valve or an exhaust valve of an engine in an assembly process of the engine.

[0002]

2. Description of the Related Art Conventionally, the tappet clearance of an intake / exhaust valve of an engine has been adjusted in the following procedure. High pressure air of a predetermined pressure is supplied from the plug hole into the combustion chamber in a state where all valves other than the valve to be adjusted are closed and the piston of the cylinder corresponding to the valve to be adjusted is stopped at the top dead center. With the slipper at one end of the rocker arm in contact with the base circle of the cam, a predetermined thickness gauge is sandwiched between the adjusting screw screwed into the other end of the rocker arm and the stem end of the valve to be adjusted. Thus, a minute gap is formed between the valve and the valve seat, and air leaks from this gap. While reading the combustion chamber pressure displayed on the manometer, the adjustment screw is rotated by a driver to adjust the size of the gap, and the combustion chamber pressure is made to match a preset value. The adjustment screw is fixed to the rocker arm by rotating a lock nut screwed into the adjustment screw by turning the nut.

[0003]

However, in the above-mentioned conventional method, even if the adjusting screw is rotated by a screwdriver to adjust the tappet to a position where an appropriate tappet clearance can be obtained, a predetermined tightening operation is performed on the lock nut by turning the nut. When the torque is applied, the adjustment screw may rotate together with the rotation of the lock nut, causing the adjusted position of the adjustment screw to shift. If the worker notices this, the adjustment can be performed again. However, if the worker does not notice, there is a possibility that an incorrectly adjusted product will flow to the next line.

The present invention has been made in view of the above circumstances, and has as its object to make it possible to easily and accurately adjust the tappet clearance of a valve without requiring the skill of an operator.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a pressure detecting means for detecting the internal pressure of a combustion chamber to which high-pressure air is supplied so as to adjust a tappet clearance of a valve. After adjusting the screwing amount of the adjusting screw into the cam follower while monitoring so that the detected combustion chamber pressure matches a preset value, an engine that tightens the lock nut to fix the adjusting screw to the cam follower Tapping clearance adjustment method, wherein the lock nut is tightened with a torque wrench that outputs a signal when the tightening torque reaches a predetermined value, and the combustion chamber pressure at the moment when the signal is output is compared with the set value. Judge whether tappet clearance is appropriate or not.

In the conventional method, when the lock nut is tightened after adjusting the screwing amount of the adjusting screw into the cam follower, the adjusting screw rotates together with the rotation of the lock nut, and the screwing amount of the adjusting screw once adjusted changes. However, the combustion chamber pressure may deviate from the set value. However, according to the above configuration, the lock nut is tightened with a torque wrench that outputs a signal when the tightening torque reaches a predetermined value, and the pressure in the combustion chamber at the moment when the signal is output is compared with a set value, thereby locking the lock nut. This ensures that the nut tightening torque has reached the predetermined value and that the combustion chamber pressure at that time matches the set value. As a result, it is possible to easily and accurately adjust the tappet clearance of the valve without requiring the skill of the operator.

According to a second aspect of the present invention, in addition to the first aspect, the judging device compares the pressure in the combustion chamber with the set value to judge whether tappet clearance is appropriate, and determines the tappet clearance. Is notified to a worker of the suitability.

[0010] According to the above configuration, the applicability of the tappet clearance is judged by the judging device, and the judgment result is notified to the operator, so that the judgment accuracy and reliability are improved as compared with the judgment by the operator's eyes.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, the transmission of the signal from the torque wrench to the determination device is performed wirelessly.

According to the above configuration, it is not necessary to connect the torque wrench and the determination device with a cord, so that the operation of the torque wrench is facilitated and the working efficiency is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 5 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a tappet clearance adjusting device, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. 2, and FIG. 5 is a graph showing criteria for judging whether tappet clearance is appropriate.

As shown in FIG. 1, a combustion chamber 3 partitioned above a piston 2 slidably fitted to a cylinder 1 is provided with a plurality of valves 5 which can be seated on a valve seat 4. The rocker arm 7 as a cam follower which is swingably pivotally supported on the rocker shaft 6, with slippers ₇₁ provided on one end thereof abuts against the cam 8, the adjusting screw 9 is screwed into the other end. The adjusting screw 9 is provided with a lock nut 10 screwed thereto.
Is locked to the rocker arm 7 so that it cannot rotate. The lower end of the adjusting screw 9 faces the stem end of the valve 5, and a thickness gauge 11 having a predetermined thickness is sandwiched between the two.

For example, 5.0 supplied from the air source 21
The high-pressure air of 0 kg / cm ² is supplied to a pressure regulating valve 23 via an air cutoff valve 22, and the pressure regulating valve 23 supplies, for example, 2.
The air adjusted to 00 kg / cm ² is supplied to a joint 26 screwed into a plug hole of the combustion chamber 3 through a throttle 24 and a check valve 25 connected in parallel. The aperture 2
A manometer 27 for detecting the pressure in the combustion chamber and an AD converter 28 for converting the output of the manometer 27 into a digital signal are provided between the joint 4 and the joint 26.

Judgment device 2 provided with microcomputer
9 includes a signal from the AD converter 28 and an F
FM receiver 31 for receiving a signal transmitted by M transmitter 30
Is input. The determination device 29 notifies the operator of the suitability of the tappet clearance adjustment based on the signals from the AD converter 28 and the FM receiver 31.
The lamp 32 and the NG lamp 33 are connected to a buzzer 34 for notifying the operator when the adjustment of the tappet clearance is defective.

The nut wrench 41 includes a pipe-shaped main body 43 having a socket 42 engageable with the lock nut 10 at a tip thereof, and handles 44, 44 fixed to an upper end of the main body 43. . When the shaft portion 46 of the driver 45 is inserted into the main body portion 43 with the socket 42 of the nut wrench 41 engaged with the lock nut 10, the tip of the shaft portion 46 becomes the groove 9 _{1 at} the upper end of the adjusting screw 9.
(See FIG. 2). Therefore, by rotating the handle portion 47 of the driver 45 projecting upward from the upper end of the nut wrench 41, the screwing amount of the adjusting screw 9 into the rocker arm 7 can be adjusted.

The torque wrench 48 is configured such that a handle 49 and a socket 50 are swingably connected via a pivot 51, and the socket 50 is connected to the main body 4 of the nut wrench 41.
3 can be engaged with any of the pair of upper and lower rectangular cross-sections 52. The torque wrench 48 is a commercially available product that is generally available, and when the tightening torque reaches a predetermined value, the socket 50 swings with respect to the handle 49, at which time a clicking sound is generated and the tightening torque is generated. Is notified to the worker that has reached the predetermined value. The FM transmitter 30 is mounted on a handle 49 of the torque wrench 48.
The M transmitter 30 outputs an FM radio signal to the receiver 31 when detecting the sound emitted by the torque wrench 48.

Next, a procedure for adjusting the tappet clearance of the valve 5 will be described.

First, with all valves other than the valve 5 to be adjusted closed, the piston 2 of the cylinder 1 corresponding to the valve 5 is located at the top dead center, and high-pressure air from the air source 21 is supplied to the air. The gas is supplied to the combustion chamber 3 via a shutoff valve 22, a pressure regulating valve 23, a throttle 24 and a joint 26. Slippers 7 ₁ of the rocker arm 7 corresponding to the valve 5 to be adjusted being in contact with the base circle of the cam 8, sandwiching a predetermined thickness gauge 11 between the adjusting screw 9 and the stem end of the valve 5 By doing
A minute gap is formed between the valve 5 and the valve seat 4.

At this time, since the air in the combustion chamber 3 leaks from the gap to the outside, a constant pressure (2.
Even if the air of 00 kg / cm ² ) is supplied, the pressure in the combustion chamber detected by the manometer 27 disposed downstream of the throttle 24 changes according to the size of the gap. For example, if the gap becomes too small because the tappet clearance is too large, the pressure in the combustion chamber detected by the manometer 27 becomes higher than a preset set value. Conversely, if the tappet clearance is too small, the gap becomes small. If the pressure becomes excessive, the pressure in the combustion chamber detected by the manometer 27 becomes lower than a preset value. The set value is, for example, 0.65 kg /
cm ^{2 to} 1.00 kg / cm ² (see FIG. 5).

Subsequently, the operator checks the position of the pointer of the manometer 27 and adjusts the pressure in the combustion chamber to 0.65 kg / c.
The screwing amount of the adjusting screw 9 is adjusted so as to fall within the range of m ^{2 to} 1.00 kg / cm ² . When the adjusting screw 9 is tightened, the tappet clearance decreases and the gap between the valve 5 and the valve seat 4 increases, so that the air leakage increases, the combustion chamber pressure decreases, and conversely, the adjusting screw 9 When the pressure is loosened, the tappet clearance increases and the gap between the valve 5 and the valve seat 4 decreases, so that the amount of air leakage decreases and the pressure in the combustion chamber increases.

The adjustment of the screwing amount of the adjusting screw 9 is performed as follows. Operator in a state of engaging the socket 42 of the nut wrench 41 to the lock nut 10, the lower end of the shaft portion 46 of the driver 45 which is inserted into the main body portion 43 of the nut wrench 41 in the groove 9 ₁ of the adjustment screw 9 By engaging the engagement and rotating the handle 47 of the driver 45 to adjust the screw-in amount of the adjusting screw 9, the pressure in the combustion chamber falls within the set value range while checking the reading of the manometer 27. When the adjustment of the screwing amount of the adjusting screw 9 is completed, the operator operates the handles 44 and 44 of the nut wrench 41 to temporarily tighten the lock nut 10, and then connects the socket 50 of the torque wrench 48 to one of the nut wrench 41. Square section 5 of
The lock nut 10 is further tightened via the nut wrench 41.

When the tightening torque of the lock nut 10 reaches a predetermined value, the socket 50 swings with respect to the handle 49 of the torque wrench 48, and generates a clicking sound to notify the operator of the completion of the tightening of the lock nut 10. Notify. FM transmitter 3
When a timing signal corresponding to the sound is output from 0, the timing signal is input to the determination device 29 via the FM receiver 31. As described above, by transmitting the timing signal using the FM radio wave, the torque wrench 48 is transmitted.
And the determination device 29 need not be connected by a code,
The operability of the torque wrench 48 is improved.

A of the combustion chamber pressure detected by the manometer 27
The determination device 29 to which the D-converted value is input determines whether or not the pressure in the combustion chamber at the moment when the timing signal is output falls within the range of the set value. The OK lamp 32 is turned on. If the combustion chamber pressure is not within the range of the set value, it is determined that there is an abnormality, the NG lamp 33 is turned on, and the buzzer 3 is turned on.
4 to notify the worker.

If the engine is provided with one intake valve and one exhaust valve for each of the four cylinders, it is determined whether the adjustment of the tappet clearance for the four intake valves is appropriate from # 1 cylinder to # 2. Cylinder → # 4
The determination is repeated four times in the order of cylinder → # 3 cylinder, and the above determination is repeated four times in the above order for the four exhaust valves. In this case, each time the determination of one cylinder is completed, it is necessary to replace the joint 26 with the plug hole of the new cylinder and rotate the crankshaft by 180 ° to move the piston 2 to the top dead center. .

As described above, the torque wrench 4 outputs a signal when the tightening torque of the lock nut 10 reaches a predetermined value.
8, the output value of the manometer at the moment when the torque wrench 48 outputs a signal is compared with a set value to determine whether or not the tappet clearance is appropriate, so that the lock nut 10 can be fastened with a constant tightening torque. Even if the adjusting screw 9 rotates together when the lock nut 10 is tightened and the tappet clearance changes, the operator is notified of the change without fail and prompts re-adjustment. Flow can be reliably prevented. In addition, since it is not necessary to rely on the operator's visual judgment to determine whether tappet clearance is appropriate or not, and since there is no need for skilled workers or cans, even unskilled workers can easily and reliably adjust tappet clearance. Becomes possible.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made.

For example, in the embodiment, the final determination as to whether or not the tappet clearance is appropriate is made in the determination device 29. However, in the invention described in claim 1, the torque wrench 48 is used.
Even if the operator compares the pressure in the combustion chamber at the moment when the signal is output and the set value with the naked eye of the operator, the rotation of the adjusting screw 9 can be reliably recognized, so that a predetermined effect can be obtained. In the embodiment, the rocker arm 7 is exemplified as the cam follower, but the cam follower may be a swing arm.

[0029]

As described above, according to the first aspect of the present invention, the lock nut is tightened with the torque wrench that outputs a signal when the tightening torque reaches a predetermined value.
By comparing the pressure in the combustion chamber at the moment when the signal is output with the set value, the tightening torque of the lock nut has reached a predetermined value, and the pressure in the combustion chamber at that time matches the set value. Is surely guaranteed. As a result, it is possible to easily and accurately adjust the tappet clearance of the intake valve or the exhaust valve without requiring the skill of the operator.

According to the second aspect of the present invention,
The suitability of tappet clearance is determined by the determination device,
In addition, since the determination result is notified to the worker, the determination accuracy and reliability are improved as compared with the determination by the operator's eyes.

According to the invention described in claim 3,
Since it is not necessary to connect the torque wrench and the determination device with a cord, the operation of the torque wrench is facilitated and the working efficiency is improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a tappet clearance adjustment device.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is a graph showing criteria for judging whether tappet clearance is appropriate or not.

[Explanation of symbols]

 Reference Signs List 3 Combustion chamber 5 Valve 7 Rocker arm (cam follower) 9 Adjust screw 10 Lock nut 27 Manometer (pressure detecting means) 29 Judging device 48 Torque wrench

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norihisa Ikemura 1907 Hiratacho, Suzuka City, Mie Prefecture Honda Motor Co., Ltd. Suzuka Factory

Claims (3)

[Claims] An internal pressure of a combustion chamber (3) to which high-pressure air is supplied is detected by a pressure detecting means (27) in order to adjust a tappet clearance of a valve (5), and the detected pressure of the combustion chamber is set in advance. After adjusting the screwing amount of the adjusting screw (9) into the cam follower (7) while monitoring so as to match the set value, the lock nut (10) is adjusted.
A torque tap wrench (48) for outputting a signal when the tightening torque reaches a predetermined value, wherein the lock nut (10) is tightened to fix the adjusting screw (9) to the cam follower (7). ), And determining whether the tappet clearance is appropriate by comparing the pressure in the combustion chamber at the moment when the signal is output with the set value. 2. The apparatus according to claim 1, wherein the determination device determines the suitability of the tappet clearance by comparing the pressure in the combustion chamber with the set value, and notifies the worker of the determined suitability of the tappet clearance. Item 2. The tappet clearance adjustment method for an engine according to Item 1. 3. A torque wrench (48) is connected to a determination device (2).
The method according to claim 2, wherein the transmission of the signal to (9) is performed wirelessly.