JPH09303120A - Valve bridge height adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy adjusting a height of a valve bridge, by providing a means respectively turn operating an adjusting screw and a lock nut, and controlling turn operation of the lock nut and the adjusting screw while measuring a height of the valve bridge based on a prescribed program. SOLUTION: In height adjustment of a valve bridge 2 slidably fitted to a bridge guide 3 positioned in the center between 2-piece-set of valves 1a, 1b of a 4-valve engine, a lock nut 5 and an adjusting screw 4 are once loosened, a clearance is provided from the valve 1a. Next, the adjusting screw 4 is started to be tightened, here, tightening torque of the adjusting screw 4 is continuously detected, when a rise up of the then torque is detected, the adjusting screw 4 is decided to lead to an adjusting point, tightening of the adjusting screw 4 is stopped, the lock nut 5 and the adjusting screw 4 are fixed to the valve bridge 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a height adjusting device for an engine valve bridge.

[0002]

2. Description of the Related Art For example, in a 4-valve engine, 2
A valve bridge that straddles two valves is provided, and the two valves are driven by the reciprocating motion of the valve bridge accompanying the rotation of the camshaft. In that case, the height of the valve contact surface of the valve bridge needs to be adjusted in order to synchronize the opening and closing of the two valves. This height adjustment is performed by displacing the adjusting screw of the valve bridge that hits the valve to a specified height with a driver or the like, and after the adjustment, the adjusting screw is fixed with a lock nut.

[0003]

However, such manual adjustment of the height requires a lot of time and labor, and variations occur due to sensuous individual differences. In addition, the adjustment height may be slightly changed after the lock nut is tightened.

The present invention has been made in view of the above problems, and provides a device capable of automatically adjusting the height of a valve bridge by an adjusting screw and then fixing the adjusting screw with a lock nut with high accuracy. To aim.

[0005]

According to the first invention, FIG.
And a valve bridge that opens and closes at least two valves in synchronization with the camshaft rotation of the engine,
As a height adjusting device for the valve bridge with respect to the valve drive mechanism, which includes an adjusting screw for adjusting the height of the valve contact surface and a lock nut for fixing the adjusting screw, a means a for rotating the adjusting screw, Means b for rotating the lock nut, means c for measuring the height of the valve bridge, and means for controlling the rotating operation of the lock nut and the adjusting screw while measuring the height of the valve bridge based on a predetermined program. d and means e for displaying the adequacy of the bridge height adjustment based on this control.

In the second invention, as the means d for controlling the turning operation of the lock nut and the adjusting screw in the first invention, the lock nut is loosened, and then the adjusting screw is loosened by a predetermined rotation angle, and the valve bridge height is increased. The means for initializing the measured value of, the means for tightening the adjusting screw after this initialization, the means for judging whether the valve bridge height changes immediately at the beginning of tightening, and the valve bridge height from this judgment result. If the valve bridge height does not change immediately from the result of the judgment, the adjustment screw is stopped and the adjustment screw is loosened by a predetermined rotation angle. When tightened and the valve bridge height is within the specified range, adjust Stop means, a means for determining whether or not the valve bridge height is within a predetermined range after this stop, and a means for tightening the lock nut when the valve bridge height is within a predetermined range based on this determination result. From the determination result, when the valve bridge height is not within the predetermined range, a means for retrying from the process of loosening the adjusting screw by a predetermined rotation angle, and a means for determining whether the valve bridge height is within the predetermined range after tightening the lock nut Based on this determination result, OK is given when the valve bridge height is within the predetermined range, and NG when it is not within the predetermined range.
And means for displaying.

In the third invention, as a means for controlling the rotating operation of the lock nut and the adjusting screw in the first invention, the valve bridge height is constantly changed by loosening the lock nut and then the adjusting screw. No means to find the initial state, means to find the initial state to initialize the measured value of the valve bridge height, and after this initialization, tighten the adjust screw and adjust the valve bridge height when it reaches the specified value. A means for stopping the screw, a means for obtaining the rotation angle of the adjusting screw from when the valve bridge height starts to be displaced toward the tightening side until it reaches a specified value, and after adjusting the screw stops, adjust the adjusting screw by a considerable amount. After loosening and then tightening the lock nut, after And means for displaying the Tsu measurement height of di- and provided.

In the fourth aspect of the invention, as shown in FIG. 12, a valve bridge that synchronously opens and closes at least two valves according to the rotation of the camshaft of the engine, an adjusting screw that adjusts the height of the valve contact surface, In a valve bridge height adjusting device for a valve drive mechanism including a lock nut for fixing the adjusting screw, a means f for rotating the adjusting screw, a means g for rotating the lock nut, and a valve bridge. A means i for applying a predetermined pressing load, a means h for measuring the tightening torque of the adjusting screw, and a state in which the lock nut and the adjusting screw are loosened while applying a predetermined pressing load to the valve bridge when adjusting the height of the valve bridge. Tighten the adjusting screw from the And means j to tighten the lock nut to stop the adjusting screw reaches to, the provision.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a valve bridge height adjusting method will be described first. 1a and 1b are a pair of valves of a 4-valve engine, 2 is a valve bridge which is freely slidable on a bridge guide 3 located at the center between these valves, and 4 is for adjusting a clearance between the valve 1a and one side thereof. Adjusting screws 5 and 5 are lock nuts for fixing the adjusting screw 4. When adjusting the height of the valve bridge 2, the lock nut and the adjusting screw 4 are once loosened to leave a gap with the valve 1a. When the clearance is generated, the load on the adjusting screw 4 is removed, and the clearance of the other valve 1b becomes zero. Then, tighten the adjusting screw 4. At this time, the tightening torque of the adjusting screw 4 is continuously detected, and the tightening is stopped when the torque rises. At the height at which the adjusting screw 4 hits the valve 1a, the clearance between the valves 1a and 1b on both sides becomes zero.

Therefore, by tightening while detecting the tightening torque of the adjusting screw 4, the tightening torque rapidly increases according to the tightening amount as shown in FIG. 2 from the time when the adjusting screw 4 contacts the valve 1a. Since it rises, if you detect the rise of this torque,
It is determined that the adjusting screw 4 has reached the adjustment point, and the tightening of the adjusting screw 4 is stopped. Then, adjust the screw 4 with the lock nut 5.
Is fixed to the valve bridge 2. In this case, in order to generate the tightening torque of the adjusting screw 4, a predetermined pressing load W is applied to the center of the valve bridge 2 during the height adjustment. Instead of detecting the tightening torque of the adjusting screw 4, the gap between the adjusting screw 4 and the valve 1a may be detected from the voltage fluctuation.

FIG. 3 shows the structure of an apparatus for automatically adjusting the height of the valve bridge 2. Above the assembly line 10, there is provided a traveling crane 11 capable of moving vertically and horizontally within a predetermined range on a plane. This crane 11 has a height adjustment device 12
The main body portion 13 is suspended by a lifting cylinder 14. 15 is a rail extending in the direction along the line 10, 1
7 is a roller rolling on the rail 15, 16 is a line 1
A rail extending in the direction crossing 0, 18 is the rail 16
With the rollers rolling over, the lower rail 16 is connected to the upper roller bracket 17a, and the lower roller bracket 18a is connected to the base 19 of the crane 11. Shaft 2 slidably passing through base 19 of crane 11
0 is provided, the lower end of which is fixed to the plate 23 of the body portion 13 of the height adjusting device 12. A lower end of a guide rod 21 that is slidable on the base 19 of the crane 11 is coupled to a bracket 22 that can move on the shaft 20.
Support 4

In the main body portion 13 of the height adjusting device 12, a machine frame 26 is formed by the upper and lower plates 23, 24 and a plurality of rods 25 connecting them. Machine frame 26
Means 27 for rotating the adjusting screw 4 and the lock nut 5 of the valve bridge 2 are mounted on the plate 24. The operating means 27 is a modification of an existing lock nut device that can handle two kinds of works with one shaft, and a rotating jig 28 that projects below the plate of the machine frame 26.
As shown in FIG. 5, a socket 29 having a square hole into which the lock nut 5 engages and a driver 30 extending coaxially with the socket 29 are provided. Although not shown in the nut runner 27, a switching mechanism that selectively transmits the rotational force of the actuator 31 (AC servo motor) to the socket 29 and the driver 30, and a brake that restrains the rotation of the driver 30 when the lock nut 5 is tightened. And a mechanism are provided.

Reference numeral 32 denotes a pressing mechanism for applying a predetermined load to the center of the valve bridge 2, and its actuator 33.
The (AC servomotor) is mounted on the plate 24 of the machine frame 26. Plate 3 of the positioning mechanism 34 described later
5, a pressure rod 36 that vertically presses the center of the valve bridge 2 is arranged so as to be able to advance and retract in the axial direction, and a relay rod 37 that transmits the load received from the operating rod 33a of the actuator 33 to the pressure rod 36 moves the plate 35 to the plate 35. It is supported by sliding through it. Reference numeral 38 denotes a handle that projects to both sides of the machine frame 26, and is used to operate the operation switch 3 of the lifting cylinder 14.
9 and a start switch 40 for height adjustment described later.

The plate 35 of the positioning mechanism 34 is connected to the plate 24 of the machine frame 26 in parallel via a spacer 41. A guide 43 having U-shaped cross sections facing each other is formed on the lower surface of the plate 35, and a plate 44 which is seated on the locking surface (flange) of the guide 43 inside thereof is housed. Long pins 45 on the upper plate 35,
4, short pins 46 vertically project downward.
These pins 45, 46 perform a positioning function for the cylinder head 47 on the line 10 when the height of the valve bridge 2 is adjusted. The pins 45, 46 are connected to the bolt holes of the cylinder head 47 through the stepped surfaces 45a, 46a on the pin tip side. Small diameter parts 45b and 46b that can be inserted are formed.

From the nut runner 27 side to the cylinder head 4
In order to prevent the vibration from being transmitted to the 7 side, a height difference m is set between the stepped surface 45a of the pin 45 and the stepped surface 46a of the pin 46, and when positioning to the cylinder head 47, only the height difference m is set. The plate 44 floats from the locking surface in a non-contact state. As a means for detecting the positioning completion state, the stepping surface 45a of the long pin 45 is turned on via one of the short pins 46 via the actuating mechanism at the height at which the stepped surface 45a of the long pin 45 is locked (seat) to the bolt hole of the cylinder head 47. The detection switch 49 is assembled.

The controller 50 controls the actuator 31 of the rotating jig 28 and the actuator 33 of the pressing mechanism 32 according to a predetermined program. The controller 50 tightens the average value of the current to the actuator 31 of the rotating jig 28 from the average value. It has a function to detect torque. 51 is a terminal box.

The control contents will be described with reference to the flow chart of FIG. 6. At the station for adjusting the valve bridge height of the assembly line 10, an operator manually operates the traveling crane 11 and the elevating cylinder 14 on the line. When the body portion 13 is lowered toward the valve bridge 2 to be adjusted by the cylinder head 47, the body portion 1
When the pins 45 and 46 of the positioning mechanism 34 of No. 3 are inserted into the bolt holes of the cylinder head 47 and the detection switch 49 of the pin 46 is turned on, the completion of positioning is determined (step 1).

When the activation switch 40 is turned on based on the manual operation of the operator, the actuator 33 of the pressing mechanism 32 is operated (steps 2 and 3). As a result, the actuating rod 33a of the actuator 33 presses the relay rod 37, and a load W for exerting the tightening torque of the adjusting screw 4 is added to the center of the valve bridge 2 via the pressure rod 36. At the same time, the switching mechanism of the rotary jig 28 is switched to the socket 29 side, the actuator 31 of the nut runner 27 is rotationally driven in the opposite direction, and the lock nut 5 is loosened and stopped (step 4). Next, the switching mechanism of the rotary jig 28 is switched to the driver 30 side, and the actuator 31 of the nut runner 27 is also rotationally driven to adjust the adjusting screw 4
Is loosened to provide a gap with the valve 1a and stop (step 5).

From this state, the actuator 31 of the nut runner 27 is rotationally driven in the positive direction to start tightening the adjusting screw 4, and the tightening torque is continuously detected (step 6). When the tightening torque reaches the adjustment point (A in FIG. 2), it is determined that the valve bridge 2 is in contact with the valves 1a and 1b on both sides without a gap, and the tightening of the adjusting screw 4 is stopped ( Step 7). After that, while switching the switching mechanism of the rotating jig 28 to the socket 29 side, while driving the brake mechanism to restrain the rotation of the adjusting screw 4, the actuator 31 of the nut runner 27 is rotationally driven in the positive direction to lock the lock nut 5. Tighten (step 8). As a result, the adjusting screw 4 is fixed by the lock nut 5, and the valve bridge 2 is adjusted to a predetermined height at which the valves 1a and 1b on both sides come into contact with each other with zero clearance.
After this height adjustment, the actuator 33 of the pressing mechanism 32 is stopped (step 9). Then, in the reverse procedure, the main body portion 13 is moved upward from the valve bridge 2 of the cylinder head 47.
Once to release the next valve bridge 2 to be adjusted.
Will be adjusted in height.

By the way, according to this height adjustment, there is a possibility that variations in torque fluctuation detection and measurement errors may occur due to friction during tightening of the adjusting screw 4. In other words, it is difficult to accurately adjust the clearance to zero, and it is considered to be a little unreliable. for that reason,
In the flowchart of FIG. 7, a method of measuring the center height (displacement amount) of the valve bridge 2 instead of the tightening torque of the adjusting screw 4 is adopted. In this case, in the height adjusting device 12 of FIGS. 3 and 4, the pressing mechanism 32 has a built-in stroke sensor (not shown) that detects the amount of displacement of the valve bridge 2, and a monitor (not shown) that displays the measured value. No.) is provided at an appropriate place.

Describing with reference to the reference numerals of the height adjusting device 12 shown in FIGS. 3 and 4, the main body portion 13 is an object to be adjusted by the cylinder head 47 on the assembly line 10 by the manual operation of the operator. Is positioned on the valve bridge 2. At that time, the detection switch 4 of the positioning mechanism 34
When 9 is turned on, the completion of positioning is determined (step 1). Then, when the activation switch 40 is turned on by the manual operation of the operator, the actuator 33 of the pressing mechanism 32 is operated (step 2, step 3). As a result, the actuating rod 33a of the actuator 33 presses the relay rod 37, and in this case exerts a light weight (w in FIG. 1) that guarantees the guide collapse in this case via the pressure rod. At the same time, the switching mechanism of the rotary jig 28 is switched to the socket 29 side, the actuator 31 of the nut runner 27 is rotationally driven in the opposite direction, and the lock nut 5 is loosened and stopped (step 4).

In this state, the adjustment process depending on the height measurement of the valve bridge 2 is started. The adjustment method will be described with reference to FIG. 8 as well.
After the stop of the
To the actuator side of the nutrunner 27.
1 is also rotationally driven to loosen the adjusting screw 4, while the stroke sensor of the pressing mechanism 32 continuously measures the height of the valve bridge 2 being adjusted (step 5). Adjusting screw 4 is valve 1a
While in contact with, the valve bridge 2 is displaced downward as the adjusting screw 4 rotates. This is because the valve bridge 2 is supported by the valve spring and the load w of the pressing mechanism 32 via the adjusting screw 4, but since the valve spring has a stronger spring force than the load w of the pressing mechanism 32, the adjusting screw 4 is loosened. This is because the valve bridge 2 is displaced downward by a relative amount. But,
When the adjusting screw 4 is separated from the valve 1a, even if the adjusting screw 4 is loosened thereafter, the valve bridge 2 is not displaced and its height becomes constant.

When the reference height at which the valve bridge 2 does not change even if the adjusting screw 4 is loosened is determined from the detection signal of the stroke sensor, the measurement value based on the stroke sensor is initialized (auto zero) at this point (step 6,). Step 7). Then, the actuator 31 of the nut runner 27 is rotationally driven in the forward direction to start tightening the adjusting screw 4 (step 8). As a result, when the adjusting screw 4 comes into contact with the valve 1a, it starts pushing the valve bridge 2 upward. When it is determined from the detection signal of the stroke sensor that the displacement amount has reached the specified value A, the tightening of the adjusting screw 4 is stopped (step 9). Next, the rotation angle of the adjusting screw 4 from the time when the valve bridge 2 starts to be displaced until the displacement amount reaches the specified value A is obtained, and the actuator 31 of the nut runner 27 is rotationally driven in the opposite direction by a corresponding amount (step 10). . As a result, the valve bridge 2 is adjusted to a predetermined height at which it contacts the valves 1a and 1b on both sides with zero clearance. It should be noted that the symbols (1) to (8) in FIG. 8 indicate the order of transition of the height (displacement amount) of the valve bridge due to the turning operation of the adjusting screw.

After that, the switching mechanism of the rotating jig 28 is switched to the socket 29 side, while the brake mechanism is driven to restrain the rotation of the adjusting screw 4, the actuator 31 of the nut runner 27 is rotationally driven in the forward direction to lock. Tighten the nut 5 (step 11). As a result, the adjusting screw 4 is fixed by the lock nut 5. Then, while the height of the valve bridge 2 measured by the stroke sensor is displayed on the monitor, the actuator 33 of the pressing mechanism 32 is turned off (step 1
2). The operator determines whether or not the bridge height is within the applicable range (0 to a) by looking at the displayed contents.

FIG. 9 shows the height (displacement amount) of the valve bridge 2.
10 is a flowchart illustrating yet another embodiment in which the method for measuring is adopted. Although not shown, the monitor of the height adjusting device is adapted to display the suitability judgment after the height adjustment of the valve bridge 4. The height adjustment device 12 shown in FIGS.
When the detection switch 49 of No. 4 is turned on, the completion of positioning is determined (step 1). Then, when the activation switch 40 is turned on by the manual operation of the operator, the actuator 33 of the pressing mechanism 32 is operated (step 2, step 3). As a result, the operating rod 3 of the actuator 33 is
3a presses the relay rod 37, and the center of the valve bridge 2 is supported by the predetermined light load w via the pressure rod. At the same time, the switching mechanism of the rotating jig 28 is switched to the socket 29 side, the actuator 31 of the nut runner 27 is rotationally driven in the opposite direction, the lock nut 5 is loosened and stopped, while the stroke sensor of the pressing mechanism 32 causes The height of the valve bridge 2 being adjusted is continuously measured (step 4).

In this state, the adjusting screw 4
The adjustment method will be described with reference to FIG. 10 as well. After the lock nut 5 is stopped, the switching mechanism of the rotating jig 28 is switched to the driver 30 side, and the actuator 33 of the nut runner 27 is also rotationally driven to adjust the adjusting screw 4.
Is loosened by a predetermined angle (step 5). Then, when the adjusting screw 4 is stopped, the measurement value of the stroke sensor is initialized (auto zero) (step 6).

After the auto zero, the actuator 31 of the nut runner 27 is rotationally driven in the positive direction to tighten the adjusting screw 4 (step 7). At that time, it is judged from the detection signal of the stroke sensor whether or not the height of the valve bridge 2 changes immediately (step 8). If the height of the valve bridge 2 changes immediately, it is determined that there is no gap between the adjusting screw 4 and the valve 1a, auto zero is invalidated, the tightening of the adjusting screw 4 is stopped, and the adjusting screw 4 is removed. Retry from the process of loosening by a predetermined rotation angle. If the height of the valve bridge 2 does not change immediately, it is determined that there is a gap between the adjusting screw 4 and the valve 1a, auto zero is effective, and tightening of the adjusting screw 4 is continued.
When the height of the valve bridge 2 falls within the predetermined range A to B,
Stop the adjusting screw 4.

After this stop, it is judged from the detection signal of the stroke sensor whether the height of the valve bridge 2 is within the predetermined range A to B (step 9). When the height of the valve bridge 2 is out of the predetermined range A to B, a failure (NG) of the adjusting stage by the adjusting screw 4 is determined, and the adjustment screw 4 is retried from the process of loosening by a predetermined rotation angle. The valve bridge 2 has a predetermined height range A
When the value is in the range of ~ B, it is determined whether the adjustment stage of the adjusting screw 4 has passed (OK), and the lock nut 5 is tightened.

When tightening the lock nut 5,
While switching the switching mechanism of the rotary jig 28 to the socket 29 side, while driving the brake mechanism to restrain the rotation of the adjusting screw 4, the actuator 31 of the nut runner 27 is rotationally driven in the forward direction to tighten the lock nut 5 ( Step 10). As a result, the adjusting screw 4 is fixed by the lock nut 5. Then, in order to reconfirm the height adjustment, it is determined whether or not the height of the valve bridge 2 measured by the stroke sensor is within a predetermined range 0 to C, and the height of the valve bridge 2 is within a predetermined range 0 to C.
If the adjustment is passed (OK), the adjustment failure (NG) is displayed on the monitor as the final adjustment result when the value is out of the predetermined range 0 to C, while the actuator 33 of the pressing mechanism 32 is stopped ( Step 11 to Step 1
3). From the displayed contents, the operator excludes the cylinder head whose height adjustment of the valve bridge 2 is NG from the assembly line 10.

[0030]

According to the first aspect of the invention, the height adjustment by the adjusting screw of the valve bridge and the subsequent fixing by the lock nut can be automatically and efficiently processed by one adjusting device. In addition, high adjustment accuracy can be secured.

According to the second aspect of the present invention, when the height of the valve bridge is adjusted, the suitability is checked before and after the lock nut is tightened.
High reliability can be ensured because the judgment is made step by step. Also,
Initialization of valve bridge height measurements is reasonably handled, which can help reduce adjustment time.

According to the third aspect of the invention, the rotation angle from when the valve bridge starts to be displaced by tightening the adjusting screw until the displacement reaches a specified value is fed back, so that the contact surface between the adjusting screw and the valve is fed back. The height of can be adjusted accurately.

According to the fourth aspect of the present invention, the tightening torque of the adjusting screw is liable to cause variations and measurement errors, and the reliability is a little lacking. You can easily check the adjustment position of.

[Brief description of drawings]

FIG. 1 is a diagram showing a mounting state of a valve bridge for explaining an embodiment of the present invention.

FIG. 2 is a characteristic diagram of tightening torque of the adjusting screw.

FIG. 3 is an overall configuration diagram of a height adjusting device.

FIG. 4 is a partial configuration diagram of the height adjusting device.

FIG. 5 is an explanatory view of the structure of a rotary jig.

FIG. 6 is a flow chart for explaining the same control contents.

FIG. 7 is a flowchart illustrating another embodiment.

FIG. 8 is a characteristic diagram for explaining adjustment contents of the adjusting screw in the same manner.

FIG. 9 is a flowchart illustrating another embodiment.

FIG. 10 is a characteristic diagram for explaining adjustment contents of the adjusting screw.

FIG. 11 is a diagram corresponding to claims of the present invention.

FIG. 12 is a diagram corresponding to claims of the present invention.

[Explanation of symbols]

 1a, 1b Valve 2 Valve bridge 3 Bridge guide 4 Adjust screw 5 Lock nut 10 Assembly line 11 Traveling crane 12 Height adjusting device 13 Main body part 14 Lifting cylinder 26 Machine frame 27 Rotating operation means (nut runner) 28 Rotating jig 29 Socket 30 Driver 31 Nutrunner actuator 32 Pushing mechanism 33 Pushing mechanism actuator 34 Positioning mechanism 35,44 Plate 40 Start switch 43 Guide 45,46 pin 47 Cylinder head (workpiece) 50 Controller

Claims (4)

[Claims] 1. A valve bridge that opens and closes at least two valves in synchronization with the rotation of a camshaft of an engine, an adjusting screw that adjusts the height of a valve contact surface, and a lock nut that fixes the adjusting screw. In the height adjusting device for the valve bridge with respect to the valve drive mechanism including ,, means for rotating the adjusting screw, means for rotating the lock nut,
A means for measuring the height of the valve bridge, a means for controlling the rotational operation of the lock nut and the adjusting screw while measuring the height of the valve bridge based on a predetermined program, and the appropriateness of the bridge height adjustment based on this control. A valve bridge height adjusting device comprising: a means for displaying. 2. A means for controlling the turning operation of the lock nut and the adjusting screw, for loosening the lock nut and then loosening the adjusting screw by a predetermined rotation angle to initialize the measured value of the valve bridge height. A means for tightening the adjust screw after this initialization, a means for determining whether the valve bridge height changes immediately at the beginning of tightening, and a means for adjusting the adjust screw when the valve bridge height changes immediately from this determination result. A means to stop tightening and loosen the adjusting screw by a predetermined rotation angle, and to retry, and when the judgment result shows that the valve bridge height does not change immediately, tighten the adjusting screw to set the valve bridge height to the specified value. A means to stop the adjusting screw when it enters the range, and a A means for determining whether the bridge height is within a predetermined range, a means for tightening the lock nut when the valve bridge height is within a predetermined range based on this determination result, and a valve bridge height within a predetermined range based on the same determination result. If not, a means to retry from the process of loosening the adjusting screw by a predetermined rotation angle, a means to judge whether the valve bridge height is within a predetermined range after tightening the lock nut, and a valve bridge height from this judgment result. The valve bridge height adjusting device according to claim 1, further comprising: a means for displaying OK when within a predetermined range and NG when not within a predetermined range. 3. As a means for controlling the turning operation of the lock nut and the adjusting screw, means for locating an initial state in which the valve bridge height is constant and is not changed by loosening the lock nut and then the adjusting screw,
When the initial state is sought, a means for initializing the measured value of the valve bridge height, a means for tightening the adjusting screw after this initialization, and a means for stopping the adjusting screw when the valve bridge height reaches a specified value, a valve A means for obtaining the rotation angle of the adjusting screw from when the bridge height starts to be displaced to the tightening side until it reaches a specified value, and a means for loosening the adjusting screw by a considerable amount after this adjusting angle and then tightening the lock nut. And means for displaying the measured height of the valve bridge after this tightening.
Valve bridge height adjusting device described in. 4. A valve bridge that synchronously opens and closes at least two valves in accordance with rotation of a camshaft of an engine, an adjusting screw that adjusts the height of a valve contact surface of the valve bridge, and a lock nut that fixes the adjusting screw. In the height adjusting device for the valve bridge with respect to the valve drive mechanism including ,, means for rotating the adjusting screw, means for rotating the lock nut,
Means for applying a predetermined pressing load to the valve bridge, means for measuring the tightening torque of the adjusting screw,
When adjusting the height of the valve bridge, tighten the adjusting screw from the state where the lock nut and adjusting screw are loosened while applying a predetermined pressing load to the valve bridge, and stop the adjusting screw when the tightening torque reaches the specified value. A valve bridge height adjusting device comprising: a means for tightening a lock nut.