JPH10180559A - Inspecting device for installation of valve cotter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and quickly sense failed assembling of a valve cotter coupling a valve stem with a retainer. SOLUTION: A valve stem 4 is mounted on a cylinder head, and a proximity switch 20 installed on a body base 17 is positioned confronting the valve stem 4 with the set sensing distance L reserved in between, and if therein valve cotter 7 is missing, a retainer 6 is inclined by the energizing force of a valve spring 5 so that the distance L1 between its top and the switch 20 becomes smaller than L; if the cotter 7 is afloat, the distance L2 between the cotter top and switch 20 becomes smaller than L. In both cases, the proximity switch 20 is turned on to notify that the installation of the cotter is made in a poor workmanship.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve cotter assembly inspection apparatus for inspecting an assembly state of a valve cotter for coupling a valve stem and a retainer for engaging a valve spring.

[0002]

2. Description of the Related Art As is well known, the valve operating mechanism of a four-cycle engine is of an overhead valve type or a side valve type, and the overhead valve type is further divided into a push rod type, a rocker arm type, a swing arm type, a direct acting type and the like. The opening and closing timing of the intake valve and the exhaust valve is subdivided, and is often set by a cam that rotates in synchronization with the engine.

For example, in a rocker arm type engine, FIG.
As shown in the figure, an intake valve 2 for opening and closing an intake port 1a and an exhaust valve 3 for opening and closing an exhaust port 1b are provided in the cylinder head 1.
The valve stem 4 is connected to each of the valves 2 and 3. This valve stem 4 has a valve spring 5
The valve stem 4 is connected with a retainer 6 for receiving the valve spring 5. The urging force of the valve spring 5 constantly urges each of the valve stems 4 in the valve closing direction.

[0004] The valve stem 4 and the retainer 6 are connected via a plurality of divided valve cotters 7.
In the assembly line, the retainer 6 is automatically assembled with the valve cotter 7 held at a predetermined position of the valve stem 4.

Various devices for inspecting whether or not the above-mentioned valve cotter is properly assembled have been conventionally proposed.

[0006] For example, in an assembly inspection apparatus disclosed in Japanese Utility Model Laid-Open No. 3-79228, a tentacle is arranged corresponding to each of a plurality of divided pieces of a valve cotter, and whether or not each tentacle is displaced. Is detected by a rod displacement sensor, and whether or not the rod connected to the above-mentioned rod is retracted by a predetermined amount is detected by a rod displacement sensor. It is determined that the piece corresponding to is missing, and the tentacle displacement sensor is ON and the rod displacement sensor is OFF
In the case of, it is determined that the pieces are assembled correctly,
In addition, a technique is disclosed in which when both sensors are ON, it is determined that the piece is floating toward the distal end of the valve stem.

Japanese Patent Application Laid-Open No. 63-123640 discloses a technique in which one tentacle provided at the tip is rotated by 120 ° to detect a missing or floating cotter at three points.

Further, Japanese Utility Model Laid-Open No. 4-19727 discloses that
Detects the relative position between the end of the valve stem and the retainer,
A technique for inspecting whether or not the valve cotter is properly loaded based on the relative position is disclosed.

[0009]

However, in the above prior arts, each of them has a contact portion at its tip which comes into contact with the retainer or the valve cotter, and the relative movement of the contact portion causes the valve cotter to be missing or floating. Since the failure is detected, a mechanism for moving each component connected to the contact site together with the contact site is required, and the structure is complicated and the equipment cost rises. Further, since the contact portion comes into contact with the retainer or the valve cotter every inspection, the durability must be sufficiently ensured, and not only does the cost of parts increase, but also the maintenance becomes complicated due to the large number of mechanical parts.

Further, as disclosed in Japanese Patent Application Laid-Open No. 63-123640, one tentacle is rotated by 120 ° to remove a cotter,
Alternatively, in the technique of detecting a lift, a contact must be brought into contact with one valve stem three times, so that the inspection time is prolonged and the inspection efficiency is reduced, and a mechanism for rotating the contact is required. To complicate the structure.

In view of the above circumstances, the present invention not only reduces the number of components with a simple structure, reduces costs, but also has excellent durability and maintainability, and can quickly and accurately detect a defective assembly of a valve cotter. It is an object of the present invention to provide a valve cotter assembling inspection device capable of detecting an error.

[0012]

In order to achieve the above object, a first valve cotter assembly inspection apparatus according to the present invention is provided.
Inspection of an assembled state of a valve stem when a retainer for receiving a valve spring is connected to a valve stem attached to an engine unit through a plurality of divided valve cotters. The proximity switch connected to the detection unit is set opposite to the set detection distance.

A second valve cotter assembly inspection apparatus according to the present invention is characterized in that in the first valve cotter assembly inspection apparatus, the proximity switch is fixed to a vertically movable main body base.

According to a third aspect of the present invention, there is provided a valve cotter assembling inspection apparatus, wherein a retainer for receiving a valve spring is connected to a valve stem mounted on an engine unit via a plurality of divided valve cotters. In the inspection of the attachment state, at least three touch sensors that come into contact with the retainer at a set detection position are arranged on a concentric circle, and each of the touch sensors is connected to a defect detection unit.

According to a fourth aspect of the present invention, each of the touch sensors is fixed to a vertically movable main body base. .

In the first valve cotter assembly inspection apparatus, the proximity switch is directly opposed to the end of the valve stem at a set detection distance. At this time, for example, when at least one of the valve cotters is missing, one end of the retainer is closed. Since the valve is inclined in the direction of the proximity switch by receiving the urging force of the valve spring, the distance between the end of the retainer and the proximity switch becomes shorter than the set detection distance, and the failure detection signal is sent from the proximity switch to the failure detection unit. Is output. Similarly, when the valve cotter is floating toward the end of the valve stem, the distance between the end of the valve cotter and the proximity switch is shorter than the set detection distance. A failure detection signal is output. On the other hand, if all the valve cotters are properly assembled, a non-detection signal is output from the proximity switch to the defect detection unit because the distance between the proximity switch and the valve cotter and the retainer is properly maintained. Is done.

In the second valve cotter assembly inspection apparatus, in the first valve cotter assembly inspection apparatus, preferably, the proximity switch is fixed to a vertically movable main body base so that the proximity switch is mounted on the engine unit. Can be retracted during transfer.

In the third inspection apparatus for assembling a valve cotter, at least three touch sensors arranged concentrically are brought into contact with the retainer at a set detection position. If at least one of the valve cotters connecting the valve stem and the retainer is missing, or if the valve cotter is floating toward the distal end of the valve stem, the retainer tilts under the biasing force of the valve spring, A deviation occurs in the detection value of each touch sensor, and the failure detection unit detects an assembly failure of the valve cotter from the deviation. On the other hand, when all the valve cotters are properly assembled, it is determined that the assembly is proper without a large deviation occurring in the output values of the touch sensors.

In the fourth inspection apparatus for assembling a valve cotter, in the third inspection apparatus for assembling a valve cotter, preferably, the touch sensor is fixed to a vertically movable main body base, so that the touch sensor is mounted on an engine unit. Can be evacuated when is being transported.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. Reference numeral 11 in FIGS. 1 and 2 denotes an assembly line for assembling a cylinder unit.

A conveyor 12 is laid on the assembly line 11, and a cylinder head 1 constituting an engine unit mounted on a pallet 13 on the conveyor 12 is provided.
Moves and is sequentially transferred to an assembling process and an inspection process provided on the way.

In the assembling process of the cylinder head 1, the components constituting the valve mechanism are assembled to the cylinder head 1. That is, the valve stem 4 for fixing the intake valve 2 and the exhaust valve 3 respectively is inserted into the tip, and the valve spring 5 is loosely inserted. Thereafter, the retainer 6 receiving the valve spring 5 is attached to the tip of the valve stem 4. It is assembled via a plurality of (for example, two pieces) divided valve cotters 7. Incidentally, four intake valves 2 and four exhaust valves 3 are used in the cylinder head 1 shown in the present embodiment.

In the inspection step, an inspection station 14 is provided, and a frame 15 of the inspection station 14 is laid on the conveyor 12.
An elevating cylinder 16 as a support member is suspended from substantially the center of the cylinder.

The center of the main body base 17 is connected to the end of the elevating cylinder 16, and four corners of the main body base 17 are slidably inserted and supported by guide rods 18 suspended from the frame 15.

The inspection station 14 is provided with a stopper 1 which can stop and retract so as to stop the pallet 13 at a normal position.
9 and a passage sensor (not shown) for detecting that the pallet 13 has been transferred to the inspection station 14.

Eight proximity switches 20 corresponding to the valve stems 4 mounted on the cylinder head 1 are arranged on the main body base 17. The detection surface of each proximity switch 20 is the falling end of the lifting cylinder 16 and the detection distance L set in advance with respect to the tip of the valve stem 4.
When the retainer 6 is properly attached to the tip of the valve stem 4 (see FIG. 3A), the tip of the valve stem 4 is The distance from the upper surface of the retainer 6 is almost constant,
If the detection distance L in this state is shown with reference to the upper surface of the retainer 6, it is L '. The proximity switch 2
For 0, various types such as a photoelectric type and a magnetic type can be considered.

The detection distance L 'is set based on the sensitivity or characteristics of the proximity switch 20, and outputs an ON signal when the object (retainer 6, valve cotter 7) is closer than the detection distance L'. The target object is the detection distance L '
If it is farther than the above, an OFF signal is output. Although the tip of the valve stem 4 is within the detection distance L ', the sensitivity is adjusted in advance so that the tip of the valve stem 4 is not detected.

The proximity switch 20 is connected to the frame 15
Is connected to a failure detection unit 21a incorporated in a display box 21 fixed to the display box 21. The display box 21 is provided with eight display lamps 22 corresponding to the proximity switch 20. When an ON signal is output from the proximity switch 20, the display lamp 21 responds via the failure detection unit 21a. The display lamp 22 is turned on.

Next, the operation of the present embodiment having the above configuration will be described. Conveyor 1 provided on assembly line 11
When the cylinder head 1 placed on the pallet 13 is transported on the pallet 2 and the components constituting the valve operating mechanism such as the valve stem 4 and the valve spring 5 are assembled in a predetermined manner in the assembly process provided in the middle, Is transferred to the inspection process.

The inspection station 1 provided in this inspection process
In step 4, first, a passage sensor (not shown) detects the transferred pallet 13, and a predetermined delay time (for example, 2 seconds)
After the elapse, the lifting cylinder 16 suspended from the frame 15 of the inspection station 14 starts descending. On the other hand, the pallet 13 is hung on the stopper 19 and stopped at the set position.

When the lift cylinder 16 reaches the lower end, the detection surface of each proximity switch 20 fixed to the main body base 17 connected to the tip of the lift cylinder 16 is assembled to the cylinder head 1. A sensing distance L is provided at the tip of the attached valve stem 4 to face each other.

At this time, when the retainer 6 and the valve cotter 7 are properly attached to the valve stem 4, as shown in FIG. 3A, the detection surface of the proximity switch 20 is connected to the surface of the retainer 6 as shown in FIG. The proximity switch 20 outputs an OFF signal at the position of the reference detection distance L ′. On the other hand, when at least one of the divided valve cotters 7 is missing, one end of the retainer 6 is inclined upward by receiving the urging force of the valve spring 5, as shown in FIG. The distance L1 between the detection surface of the proximity switch 20 and the uppermost part of the retainer 6 is shorter than the detection distance L ', and the proximity switch 20 detects the retainer 6 and outputs an ON signal. Further, the valve cotter 7 divided into a plurality
If at least one of the valve cotters floats toward the end of the valve stem 4, as shown in FIG.
Since the distance L2 between the upper end of the switch and the detection surface of the proximity switch 20 is shorter than the detection distance L ', the proximity switch 20 detects the valve cotter 7 and outputs an ON signal.

ON output from the proximity switch 20
The signal is output from the failure detection unit 21 provided in the display box 21.
a, the corresponding display lamp 22 is turned on through the failure detection unit 21a to notify the assembly failure of the valve cotter 7 and the location of the failure. At this time, the alarm buzzer may be sounded at the same time.

When the above-described inspection process has been completed, the stopper 19 is immersed in the cylinder head 1.
Is transferred to the next step, and a new pallet 13 is transferred.

As described above, in the present embodiment, the assembly failure of the valve cotter 7 is detected by the proximity sensor 20 directly facing the tip of the valve stem 4, so that the structure is simplified and the non-contact state is maintained. The detection is excellent in durability, and the assembly failure of the valve cotter 7 can be detected with higher accuracy.

FIGS. 4 and 5 show a second embodiment of the present invention. In the present embodiment, the assembly failure of the valve cotter 7 is detected by the inclination of the retainer 6, and the first
The proximity switch 20 is attached to the main body base 17 shown in the embodiment.
, A touch sensor unit 25 is provided.

The touch sensor unit 25 includes an equilateral triangular support 26 centered on the valve stem 4 and a touch sensor 27 mounted on a side surface of the support 26. 27a is opposed to the retainer 6 so as to be freely contactable.

The defect detection unit 21a provided in the display box 21 detects whether or not the retainer 6 is tilted based on the amount of displacement of the stylus 27a of each touch sensor 27 that contacts the retainer 6 at three points. Then, when it is determined that the retainer 6 is inclined, the display lamp 22 corresponding to the touch sensor unit 25 is turned on to notify the assembly failure of the valve cotter 7.

As described above, in the present embodiment, the stylus 27a of each touch sensor 27 that makes three-point contact with the retainer 6
Since it is detected whether or not the retainer 6 is tilted based on the amount of displacement, there is no need to adjust the sensitivity as with a proximity switch, and it is easy to handle, with uniform accuracy and in a short time. Can be grasped, and the assembly failure of the valve cotter 7 can be easily detected based on the inclination of the retainer 6.

[0040]

As described above, according to the present invention,
Since the assembly failure of the valve cotter coupling the valve stem and the retainer is detected by the inclination of the retainer or the float of the valve cotter using the proximity switch, or from the inclination of the retainer using the touch sensor,
Featuring fewer mechanical parts, the structure is simplified, and as a result, not only cost can be reduced, but also durability and maintainability are excellent, and defective installation of the valve cotter can be detected electrically in a short time and accurately. Can be.

Further, by fixing the proximity switch or the touch sensor to the vertically movable main body base, the proximity switch or the touch sensor can be retracted while the engine unit is being transferred.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line II of FIG. 2 according to a first embodiment;

FIG. 2 is a side view of the assembly inspection device for the valve cotter.

FIG. 3 is a side sectional view of a main part, showing an assembly inspection of the valve cotter according to a state.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 5 according to a second embodiment;

FIG. 5 is a plan view of a main part of the assembly inspection device for the valve cotter.

FIG. 6 is a side sectional view of a cylinder head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Valve stem 5 ... Valve spring 6 ... Retainer 7 ... Valve cotter 16 ... Support member (elevating cylinder) 20 ... Proximity switch 21a ... Defect detection unit 27 ... Touch sensor

Claims (4)

[Claims] 1. A valve cotter assembling inspection apparatus for inspecting an assembling state of a valve cotter when a retainer receiving a valve spring is connected to a valve stem attached to an engine unit via a plurality of divided valve cotters. A valve cotter assembly inspection apparatus, wherein a proximity switch connected to a failure detection unit is installed at an end of the valve stem at a set detection distance. 2. The valve cotter assembly inspection apparatus according to claim 1, wherein said proximity switch is fixed to a vertically movable main body base. 3. A valve cotter assembly inspection apparatus for inspecting an assembly state of a valve cotter when a retainer for receiving a valve spring is connected to a valve stem attached to an engine unit via a plurality of divided valve cotters. A valve cotter assembly inspection apparatus, wherein at least three touch sensors that contact the retainer at a set detection position are concentrically arranged, and each of the touch sensors is connected to a failure detection unit. 4. The assembly inspection apparatus according to claim 3, wherein each of the touch sensors is fixed to a vertically movable main body base.