JPH09177520A - Valve bridge adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct the adjustment work of the adjust screw of a valve bridge with high efficiency and precision. SOLUTION: A valve bridge adjustment device is provided with a bridge press mechanism 42 which has a press portion 90 pressing a valve bridge 6 and an energizing member, first rotation tool 55 which can be engaged with an adjust screw 10, first motor 52, second rotary tool 72 which can be fitted into a lock nut 11, second motor 60, a current sensor 59 which detects the drive current of the first motor 52, a displacement sensor 95 which detects the height of the valve bridge 6, and a controller 56. When a current value exceeding a predetermined value is detected by the current sensor 59 or the rise of the valve bridge 6 is detected by the displacement sensor 95, the controller 56 as taking the time as reference, rotates the first motor 42 further by a predetermined amount, and thereafter, the same locks the first motor 52 and rotates the second motor 60 so as to rotate the second rotary tool 72.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve bridge adjusting device used to adjust a screwing amount of an adjusting screw of a valve bridge which constitutes a part of a valve operating mechanism of an engine.

[0002]

2. Description of the Related Art As shown in FIG. 12, in a valve operating mechanism 1 for driving an intake valve or an exhaust valve of a relatively large engine such as an automobile, two valves 3, which are arranged in parallel with each other on a cylinder head 2. If two rockers 4 are driven simultaneously by one rocker arm 5, a valve bridge 6 is used. Both ends of the valve bridge 6 are valves 3,
4 is in contact with the end faces 3a, 4a of the valve 4, and when the end face 6a at the substantially central portion of the valve bridge 6 is pushed by the rocker arm 5, the two valves 3, 4 simultaneously move in the valve opening direction. The valve bridge 6 is movably supported in the vertical direction by fitting a vertical hole 6b into a pin-shaped guide member 7 provided upright on the cylinder head 2. The valves 3 and 4 are biased in the valve closing direction by valve springs 8. The rocker arm 5 is driven by a drive member 9 such as a push rod that interlocks with the crankshaft.

Valve operating mechanism 1 using the above valve bridge 6
In order to drive the two valves 3 and 4 in synchronism with each other at precise timing, in order to drive the two valves 3 and 4,
It is necessary to keep the positional relationship between 4a and the valve bridge 6 accurate. Therefore, the adjusting screw 10 is provided on one end side of the valve bridge 6, and the screwing amount is adjusted so that the valve bridge 6 contacts the end faces 3a, 4a of the valves 3, 4 with an appropriate load. This adjusting screw 10 will be
Fixed by

In order to adjust the screwing amount of the adjusting screw 10, the adjusting screw 10 is conventionally rotated by a manual rotating tool such as a screwdriver, and the tip 10a thereof is in contact with the end face 3a of the valve 3 (seating position). After screwing in up to 45 ° (1/8
Rotation) The adjusting screw 10 is rotated. Then, while the rotation of the adjusting screw 10 is locked by the above tool, the adjusting nut 10 is fixed by tightening the lock nut 11 by a second rotating tool such as a wrench.

[0005]

Since the above adjustment work needs to be repeated a plurality of times for each cylinder when assembling a cylinder head for one engine, not only is the work efficiency extremely poor by manual work, , Adjustment errors are likely to occur due to individual differences among workers. In particular, in order to know that the adjusting screw has been seated on the end face of the valve, there is a tendency to rely on the intuition of the worker, which requires not only skill but also a very nervous work.

Therefore, an object of the present invention is to make it possible to efficiently perform the work of screwing a predetermined amount of the adjusting screw of the valve bridge and the work of tightening the lock nut, avoiding the occurrence of adjustment variations, and enabling accurate adjustment. To provide a bridge adjusting device.

[0007]

The valve bridge adjusting device of the present invention, which has been developed to achieve the above object, has a pressing portion contacting an end surface of the valve bridge and the pressing portion of the valve bridge. A bridge pressing mechanism having a biasing means for pushing in the direction, a first rotary tool having a tip end portion having a shape capable of engaging with the operating end of the adjusting screw, and a first rotary tool connected to the first rotary tool. An electric first motor for rotating the rotary tool, a first rotary tool which is concentric with the first rotary tool on the outer peripheral side of the first rotary tool, and is movable in the axial direction relative to the first rotary tool. A second rotating tool having a socket portion having a shape capable of being fitted to the lock nut of the adjusting screw on the tip side, and the second rotating tool is relatively moved in the axial direction with respect to the first rotating tool. A position switching actuator that can be driven, a second motor that is connected to the second rotary tool and that generates a torque that rotates the second rotary tool, and a drive current that is supplied to the first motor. And a current sensor that detects a drive current exceeding a predetermined value as a reference, the first motor is further rotated by a predetermined angle, the rotation of the first motor is locked, and the first motor is locked. The control means for activating the position switching actuator in the direction of fitting the socket portion of the rotary tool of No. 2 into the lock nut and rotating the second motor in the direction of tightening the lock nut.

By supplying a drive current to the first motor with the bridge pressing mechanism pressing the vicinity of the central portion of the valve bridge (almost on the extension line of the guide member) to the cylinder head side, the first rotary tool is operated. It rotates and the adjusting screw moves forward. When the tip of the adjusting screw contacts (seats) the end surface of the valve, the valve bridge tries to rise against the elastic force of the urging means of the pressing mechanism, increasing the load on the first motor and increasing the drive current. Rises.

The first motor is further rotated by a predetermined amount (for example, 45 °) on the basis of the time point when the increase of the drive current is detected by the current sensor, and the adjustment screw becomes the specified screwing amount. Next, the first rotary tool is fixed by locking the first motor, and the second rotary tool is moved forward by the position switching actuator so that the socket portion can be fitted into the lock nut. Become. After that, the second motor rotates,
By the second rotary tool tightening the lock nut,
Adjust screw is fixed.

The valve bridge adjusting device according to the second aspect uses the displacement sensor as a means for detecting the seating of the adjusting screw. In this case, when the adjusting screw is seated on the end surface of the valve, the valve bridge tries to move up, and the change in height is detected by the displacement sensor, and the first motor further sets a predetermined amount (eg 45 °) rotated. In the valve bridge adjusting device according to the third aspect, the seating timing of the adjust screw is more accurately detected by using both the current sensor and the displacement sensor as means for detecting seating of the adjust screw.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The valve bridge adjusting device 20 shown in FIGS. 2 and 3 includes a base frame 21 installed on the floor of a factory, a horizontal guide rail 22 provided on the upper portion of the base frame 21, and a direction along the guide rail 22. The adjusting device main body 23 is movable. A transport mechanism 25 is arranged below the adjusting device main body 23, and the transport mechanism 25 can carry in the cylinder heads 2 (an example is shown in FIG. 12) of an engine having a plurality of cylinders to a predetermined position.

On the cylinder head 2, the valve mechanism 1 is arranged at a predetermined pitch for each cylinder. The adjusting device body 23 is moved in the direction of arrow A along the guide rail 22 by a distance corresponding to the arrangement pitch of the valve train 1 for each cylinder by the pitch feed actuator 26 (shown in FIG. 2). You can do it.

The adjusting device main body 23 includes a base plate 30.
A supporting structure 32 provided above the base plate 30, an elevating unit 33 movable up and down with respect to the supporting structure 32, an elevating actuator 34 for driving the elevating unit 33 in the up and down direction, and an elevating and lowering unit. Unit 33
It is provided with a guide mechanism 35 for smoothly guiding the ascending / descending operation, and the ascending / descending actuator 34 can move the ascending / descending unit 33 in the vertical direction.

The elevating unit 33 includes a movable substrate 40 which is driven up and down by the actuator 34. As shown in FIG. 4, the tool rotation mechanism 4 is attached to the movable substrate 40.
1, a bridge pressing mechanism 42, a height detecting mechanism 43 and the like are provided.

As shown in FIG. 5 and the like, the tool rotating mechanism 41 is
It has a rotatable first shaft 51 provided inside the housing 50. The first shaft 51 is rotationally driven by a servo motor 52 that functions as an electric first motor. A first rotary tool (bit) 55 is detachably connected to the lower end of the first shaft 51 via a joint member 54. The tip portion 55a of the first rotary tool 55 is located right above the adjusting screw 10 and has a shape capable of engaging with the operating end 10b of the adjusting screw 10. The tip portion 55a of the first rotary tool 55 in the illustrated example is shaped like the tip of a minus driver, but when the operating end 10b of the adjusting screw 10 is provided with a cross-shaped groove, the tip portion 55a is formed. Should be shaped like the tip of a Phillips screwdriver. When the adjusting screw 10 is a hexagonal headed bolt, a tip portion 55a having a shape like a box spanner for tightening a hexagonal nut having a hexagonal hole is adopted.

As shown in FIG. 1, the servo motor 52 is driven via a drive circuit 57 by a controller 56 functioning as a control means. The servo motor 52 is provided with a rotation angle sensor 58 such as a rotary encoder for detecting the rotation angle. Further, a current sensor 59 for detecting the drive current of the servo motor 52 is provided. The output (driving current value) of the current sensor 59 is input to the controller 56.

An air motor 60, which functions as a second motor, is provided outside the first shaft 51. The air motor 60 shown in FIG. 5 supplies the compressed air sent from the air supply source (not shown) to the air supply port 63 through the control valve to the housing 50.
The blade 64 is introduced into the inside of the engine and the blade 64 is rotated by compressed air, and the generated torque is transmitted to the second shaft 70 via the power transmission mechanism 65 such as a planetary gear mechanism. Reference numeral 66 in FIG. 5 is an outlet for compressed air.

A second rotary tool 72 is connected to the lower end side of the second shaft 70 via a joint member 71.
The second rotary tool 72 is provided concentrically with the first rotary tool 55, is rotatable relative to the first tool 55 about its axis, and is locked by a key 73 as shown in FIG. In this state, the joint member 71 is movably fitted in the axial direction (vertical direction) and is urged downward by the spring 74. The second rotary tool 72 is located right above the lock nut 11, and is provided with a socket portion 72 a having a shape that can be fitted into the lock nut 11.

The second rotary tool 72 is supported by a connecting plate 79, and is vertically moved from a raised position shown by a solid line to a lowered position shown by a two-dot chain line in FIG. Can be driven in any direction. Then, in the lowered position, the socket portion 72a projects below the tip end portion 55a of the first rotary tool 55, and the socket portion 72a can be fitted into the lock nut 11. The magnitude of the torque transmitted from the second motor 60 to the second rotary tool 72 is detected by the torque sensor 82, and is fed back to the controller 56 to give a predetermined tightening torque to the second motor 60. You can do it.

The bridge pressing mechanism 42 shown in FIG.
A vertically extending guide 85 fixed to the movable substrate 40.
A rod 86 that is vertically movable along the guide 85, a mounting plate 87 fixed to the lower end of the rod 86, and a screw portion 89 that is screwed into a screw hole 88 of the mounting plate 87.
The pressing portion 90 having the urging member 90 and the urging member 91 for urging the pressing portion 90 downward are provided. The elastic force of the urging member 91 causes the pressing portion 90 to end face 6 near the central portion of the valve bridge 6.
It is designed to be pressed toward a. Urging member 91
Has a smaller spring constant than that of the valve spring 8. An example of the biasing member 91 is a compression coil spring,
A gas spring, rubber, a variable load type cylinder device, or the like may be used.

The pressing portion 90 is rotated clockwise or counterclockwise while the lock nut 92 is loosened, so that the pressing portion 90 protrudes downward from the mounting plate 87 (see FIG. 1).
(Shown in FIG. 2) can be adjusted, and the repulsive load of the biasing member 91 against the valve bridge 6 can be adjusted. By tightening the lock nut 92, the pressing portion 90 can be fixed at the desired protrusion amount H.

A displacement sensor 95 of the bridge height detecting mechanism 43 is provided near the pressing portion 90. As shown in FIG. 4 and the like, the displacement sensor 95 is attached to a bracket 96 provided on the movable substrate 40. This displacement sensor 9
5 has a contactor 97 which can be displaced in the vertical direction.
By bringing 7 into contact with the upper end surface of the valve bridge 6, information corresponding to the height of the valve bridge 6 is converted into an electric quantity and output to the controller 56.

As in the modification of the tool rotating mechanism 41 shown in FIG. 7, an electric second motor 60 may be used instead of the air motor. The second motor 60 is mounted outside the first motor 52 in parallel and transmits the torque of the motor 60 to the second shaft 70 via a power transmission mechanism 65 such as a gear. Further, as the biasing member 91 of the bridge pressing mechanism 42, a variable load type cylinder device is adopted. Since the adjusting screw 10 of this illustrated example is a hexagonal headed bolt, the tip portion 55a of the first rotary tool 55 is shaped like a box spanner for tightening a hexagonal nut. Other than that, the basic configuration and operation are the same as those of the above-described embodiment, and therefore, parts common to those of the above-mentioned embodiment are designated by common reference numerals and description thereof is omitted.

The tool rotating mechanism 41 of this modification (FIG. 7) is provided with a braking device 100 using a friction type electromagnetic brake or the like, and the rotational force of the first shaft 51 is transmitted to a rotational force transmitting mechanism 101 such as a reduction gear. It is transmitted to the braking device 100 via. Therefore, in the case of this modification, the first rotating tool 55 is locked by stopping the rotation of the first shaft 51 by the braking device 100, and the adjusting screw 10 is tightened when the lock nut 11 is tightened by the second motor 60. It is possible to prevent the rotation of the car.

Further, as in the modification of the tool rotating mechanism 41 shown in FIG. 8, a braking device 100 such as a friction type electromagnetic brake is arranged between the output shaft of the first motor 52 and the first shaft 51. Good. Also in this case, the first rotating tool 55 is locked by the braking device 100 when the lock nut 11 is tightened by the second motor 60, and the adjusting screw 1
It is configured so as to prevent the zero rotation.

Next, the operation of the valve bridge adjusting device 20 having the above structure will be described. The cylinder head 2 of the engine having the valve operating mechanism 1 to be adjusted is carried into a predetermined position below the adjusting device body 23 by the transfer mechanism 25.
The adjusting device body 23 is located directly above the first valve mechanism 1. The elevating actuator 34 lowers the elevating unit 33, and the pressing portion 90 of the bridge pressing mechanism 42 abuts near the central portion of the valve bridge 6 (almost on the extension line of the guide member 7), so that the urging member 91 repels. The valve bridge 6 is pressed against the cylinder head 2 side by the load. Further, the contact 97 of the displacement sensor 95 contacts the upper end surface of the valve bridge 6.

After that, a drive current is supplied to the servomotor 52 as the first motor, the first shaft 51 rotates clockwise, and the tip portion 5 of the first rotary tool 55.
The adjustment screw 10 is rotated clockwise (in the direction in which the adjustment screw 10 is screwed toward the valve 3) by fitting the operation end 10b of the adjustment screw 10 with the adjustment screw 5a.

As described above, the adjusting screw 1
0 is screwed toward the valve 3 and its tip 10a is seated on the end surface 3a of the valve 3 and then the adjusting screw 10
Is further screwed, the valve bridge 6 tries to rise against the elastic force of the biasing member 91. Therefore, the load on the servomotor 52 increases, and the drive current increases as shown in FIG. Further, as the valve bridge 6 is displaced upward, the output waveform of the displacement sensor 95 changes as shown in FIG.

When the seating of the valve bridge 6 is detected by the current sensor 59 and the displacement sensor 95, the first motor 52 is stopped as shown in FIG. After that, the first motor 52 is driven so that the adjusting screw 10 is further screwed clockwise by 45 ° (1/8 rotation) with reference to the seated position. In this way, the adjusting screw 10 becomes the specified screw-in amount.

Then, the position switching actuator 80 is actuated to the descending side, so that the socket portion 72a of the second rotary tool 72 descends to a position where it can be fitted into the lock nut 11. Further, the rotation of the first motor 52 is locked. As a means for locking, a holding current for suppressing the rotation of the first motor 52 may be supplied to the motor 52, or a tool rotation provided with a braking device 100 such as an electromagnetic brake as shown in FIG. 7 or 8. In the case of the mechanism 41, the rotation of the first shaft 51 is locked by the braking device 100. By thus locking the rotation of the first rotary tool 55, the rotation of the adjusting screw 10 is stopped via the first rotary tool 55. After that, the second motor 60 rotates to rotate the second shaft 70 in the clockwise direction. While the torque sensor 82 detects the transmitted torque, the socket portion 72a tightens the lock nut 11 to the specified torque, and the adjust torque is adjusted. The screw 10 is fixed.

In the above embodiment, since the seating of the adjusting screw 10 is detected by the combination of the signals of both the current sensor 59 and the displacement sensor 95, the displacement sensor 95
The instability of the output can be compensated by the output of the current sensor 59. Therefore, the seating of the adjusting screw 10 can be accurately detected. However, in carrying out the present invention, the seating of the adjusting screw 10 may be detected by the signal of only the current sensor 59 or only the displacement sensor 95, or by using both signals in combination.

After the adjustment of the valve bridge 6 of the first valve mechanism 1 is completed as described above, the elevating actuator 34 raises the elevating unit 33, and the pitch feeding actuator 26 further causes the adjusting device main body 23 to rise.
Is moved to the position of the second valve mechanism 1 and then the same adjustment work as above is repeated. In this way, the adjusting screw 10 of the valve bridge 6 of the valve train 1 of all cylinders
Can be adjusted, and all the lock nuts 11 can be automatically tightened.

[0033]

According to the present invention, the adjusting screw is rotated by the first motor while the valve bridge is pressed by the pressing portion of the bridge pressing mechanism with an appropriate force, and the adjusting screw is seated on the end face of the valve. The rise in the drive current of the first motor that occurs is detected by the current sensor, and the adjustment screw is further rotated by a predetermined amount based on this seating position, so the correct amount of the adjustment screw is screwed in. And a pair of valves driven through the valve bridge can be operated correctly. Further, even when the displacement sensor detects that the adjust screw is seated, it is possible to screw in the correct amount of the adjust screw based on the seated position. Further, by using both the output of the current sensor and the output of the displacement sensor, the seating timing of the adjusting screw can be detected more accurately.

[Brief description of the drawings]

FIG. 1 is a schematic view of a valve bridge adjusting device showing an embodiment of the present invention.

FIG. 2 is a side view showing the entire apparatus shown in FIG.

FIG. 3 is a front view showing the whole of the apparatus shown in FIG.

FIG. 4 is an enlarged front view of a part of the apparatus shown in FIG.

5 is a longitudinal sectional view showing a tool rotating mechanism of the apparatus shown in FIG.

FIG. 6 is an enlarged vertical sectional view showing a part of the tool rotating mechanism shown in FIG.

FIG. 7 is a cross-sectional view showing a modification of the tool rotating mechanism and the biasing means.

FIG. 8 is a cross-sectional view showing still another modified example of the tool rotation mechanism.

9 is a diagram showing an output waveform of a current sensor of the device shown in FIG.

10 is a diagram showing an output waveform of a displacement sensor of the apparatus shown in FIG.

11 is a diagram showing drive timings of a motor and a sensor of the apparatus shown in FIG.

FIG. 12 is a cross-sectional view of a part of a valve mechanism having a valve bridge.

[Explanation of symbols]

 1 ... Valve Operating Mechanism 2 ... Cylinder Head 3, 4 ... Valve 6 ... Valve Bridge 7 ... Guide Member 10 ... Adjust Screw 11 ... Lock Nut 20 ... Valve Bridge Adjusting Device 41 ... Tool Rotating Mechanism 42 ... Bridge Pressing Mechanism 52 ... First Motor 55 ... First rotary tool 56 ... Controller (control means) 59 ... Current sensor 60 ... Second motor 72 ... Second rotary tool 72a ... Socket part 80 ... Position switching actuator 82 ... Torque sensor 90 ... Pressing Part 91 ... Biasing member (biasing means) 95 ... Displacement sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seizo Fukumoto 1-9-15 Mizusawa, Higashi-Osaka City, Osaka Prefecture

Claims (5)

[Claims] 1. A device for adjusting the screw-in amount of an adjusting screw of a valve bridge movably supported in an axial direction of a guide member provided on a cylinder head, the pressing portion being in contact with an end face of the valve bridge. And a bridge pressing mechanism having a biasing means for pressing the pressing portion toward the valve bridge, a first rotary tool having a tip end portion having a shape capable of engaging with the operating end of the adjusting screw, and the first rotating tool. An electric first motor connected to the tool for rotating the first rotary tool; and a first rotary tool concentrically provided with the first rotary tool on the outer peripheral side of the first rotary tool. On the other hand, a second rotary tool having a socket portion that is relatively movable in the axial direction and has a shape on the tip side that can be fitted into the lock nut of the adjusting screw; A position switching actuator capable of moving the rotary tool relative to the first rotary tool in the axial direction, and a torque that is connected to the second rotary tool and rotates the second rotary tool. A second motor, a current sensor for detecting a drive current supplied to the first motor, and a time point at which the first motor detects a drive current exceeding a predetermined value. After the rotation, the rotation of the first motor is locked, and the position switching actuator is actuated in the direction in which the socket portion of the second rotary tool is fitted into the lock nut and in the direction in which the lock nut is tightened. A valve bridge adjusting device comprising: a control unit that rotates the second motor. 2. A device for adjusting the screw-in amount of an adjusting screw of a valve bridge movably supported in an axial direction of a guide member provided on a cylinder head, the pressing portion being in contact with an end face of the valve bridge. And a bridge pressing mechanism having a biasing means for pressing the pressing portion toward the valve bridge, a first rotary tool having a tip end portion having a shape capable of engaging with the operating end of the adjusting screw, and the first rotating tool. A first motor connected to the tool for rotating the first rotary tool; and a first motor concentric with the first rotary tool on the outer peripheral side of the first rotary tool and axially extending with respect to the first rotary tool. A second rotary tool having a socket portion that is relatively movable to the front end and has a shape that can be fitted to the lock nut of the adjust screw on the tip side; and the second rotary tool. A position switching actuator that is capable of axially moving relative to the first rotary tool, and a torque that is connected to the second rotary tool and generates a torque that rotates the second rotary tool. A displacement sensor that includes a motor No. 2 and a contactor that contacts the upper end surface of the valve bridge and converts information about the height of the valve bridge into an electric signal and outputs the electric signal; and the displacement sensor raises the valve bridge. In a direction in which the rotation of the first motor is locked and the socket portion of the second rotary tool is fitted into the lock nut after the first motor is further rotated by a predetermined angle with reference to Control means for activating the position switching actuator and rotating the second motor in a direction in which the lock nut is tightened. Valve bridge adjustment device for. 3. A device for adjusting the screw-in amount of an adjusting screw of a valve bridge movably supported in an axial direction of a guide member provided on a cylinder head, the pressing portion being in contact with an end face of the valve bridge. And a bridge pressing mechanism having a biasing means for pressing the pressing portion toward the valve bridge, a first rotary tool having a tip end portion having a shape capable of engaging with the operating end of the adjusting screw, and the first rotating tool. An electric first motor connected to the tool for rotating the first rotary tool; and a first rotary tool concentrically provided with the first rotary tool on the outer peripheral side of the first rotary tool. On the other hand, a second rotary tool having a socket portion that is relatively movable in the axial direction and has a shape on the tip side that can be fitted into the lock nut of the adjusting screw; A position switching actuator capable of moving the rotary tool relative to the first rotary tool in the axial direction, and a torque that is connected to the second rotary tool and rotates the second rotary tool. A second motor, a current sensor for detecting a drive current supplied to the first motor, and a contactor in contact with the upper end surface of the valve bridge, and information about the height of the valve bridge is an electrical signal. And a displacement sensor for converting and outputting the first motor to a predetermined angle based on a time point when the current sensor detects a drive current exceeding a predetermined value or when the displacement sensor detects a rise of the valve bridge. After the rotation, the rotation of the first motor is locked, and the position is cut in the direction in which the socket portion of the second rotary tool is fitted into the lock nut. Actuates the use actuator and valve bridge adjusting apparatus characterized by comprising a control means for rotating the second motor in a direction to tighten the lock nut. 4. A torque sensor is provided for detecting the magnitude of torque transmitted from the second motor to the second tool, and when the torque sensor detects a torque exceeding a specified value. The valve bridge adjusting device according to any one of claims 1 to 3, further comprising a controller that stops the rotation of the second motor. 5. The pressing portion of the bridge pressing mechanism is arranged so as to press on the extension line of the guide member located near the central portion of the valve bridge. The valve bridge adjusting device according to item 1.